Metastasis inhibitor composition comprising a phospholipid-linked glycosaminoglycan and method for inhibiting metastasis employing the same

FIELD OF THE INVENTION
This invention relates to phospholipid- or lipid-linked glycosaminoglycans, a process for producing the same and metastasis inhibitors.
BACKGROUND OF THE INVENTION
During the process of metastasis development, it is known that a cancer cell which has strayed into a blood vessel or lymphoduct adheres to an endothelial cell or to its extracellular matrix (so-called basement membrane) and the thus adhered cancer cell permeates into the extracellular matrix to develop a new metastatic lesion in the tissue. For example, S. Korach et al. (Cancer Research, 46, 3624-3629, 1986) reported that they have divided cancer cells into a high metastatic group and a low metastatic group and through their cancer cell cloning studies, conducted in vitro adhesion tests of cancer cells to cultured endothelial cells. As a result, the adhesiveness of cancer cells to blood vessel endothelial cells or to their extracellular matrices is closely related to metastasis of cancer cells because the high metastatic group cancer cells showed a high adhesiveness while the low metastatic cells showed a low adhesiveness.
On the other hand, the peptide sequence GRGDS (Gly-Arg-Gly-Asp-Ser) of the cell adhesion moiety of fibronectin, which is a component of the extracellular matrix, competitively inhibits binding between cancer cells and the extracellular matrix. Yamada et al. (Science, 233, 467-470, 1986) reported that the peptide GRGDS inhibited lung metastasis of B16F10 cells in mice. These results indicate that a substance which has cell adhesion inhibitory activity in a small amount could be used as a metastasis inhibitor.
The present invention has been accomplished based on a finding that certain types of phospholipid- or lipid-linked glycosaminoglycans can inhibit adhesion of cancer cells to blood vessel endothelial cells and their extracellular matrices and, as a result, can inhibit metastasis of cancer cells.
DESCRIPTION OF THE INVENTION
The present invention relates to phospholipid- or lipid-linked glycosaminoglycans, a process for producing the same and metastasis inhibitors containing the same or the salts thereof.
As shown in Table 1, glycosaminoglycan is a long chain polysaccharide which consists of recurring units of disaccharides or tetrasaccharides including D-glucosamine or D-galactosamine, D-glucuronic acid, L-iduronic acid and/or D-galactose. Examples of known glycosaminoglycans include hyaluronic acid, chondroitin, chondroitin sulfate A, chondroitin sulfate C, chondroitin sulfate D, chondroitin sulfate E, chondroitin sulfate K, chondroitin polysulfate, dermatan sulfate, heparin, heparan sulfate, keratan sulfate and keratan polysulfate.
TABLE 1______________________________________Glycosaminoglycan Hexosamine Uronic acid______________________________________Hyaluronic acid GlcNAc GlcUA(MW, 1,000-10,000,000)Chondroitin GalNAc GlcUA(MW, 1,000-100,000)Chondroitin sulfate A GalNAc (4S) GlcUA(MW, 1,000-100,000)Chondroitin sulfate C GalNAc (6S) GlcUA(MW, 1,000-100,000)Chondroitin sulfate D GalNAc (6S) GlcUA (2S)(MW, 1,000-100,000)Chondroitin sulfate E GalNAc (4S,6S) GlcUA(MW, 1,000-100,000)Chondroitin sulfate K GalNAc (4S) GlcUA (3S)(MW, 1,000-100,000)Chondroitin polysulfate GalNAc (S) GlcUA (S)(MW, 1,000-150,000)Dermatan sulfate GalNAc (4S) IduUA, GlcUA(MW, 1,000-20,000)Heparin GlcNS (6S) GlcUA, IduUA (2S)(MW, 1,000-20,000)Heparan sulfate GlcNS (NAc,S) GlcUA, IduUA (2S)(MW, 1,000-20,000)Keratan sulfate GlcNAc (6S) Gal(MW, 1,000-20,000)Keratan polysulfate GlcNAc (6S) Gal (6S)(MW, 1,000-20,000)______________________________________ GlcNAc: Nacetyl-D-glucosamine GalNAc: Nacetyl-D-galactosamine GlcNS: Dglucosamine Nsulfate GlcUA: Dglucuronic acid IduUA: Liduronic acid Gal: Dgalactose S: Osulfate
The phospholipid- or lipid-linked glycosaminoglycan of the present invention can be used as a salt, preferably with an alkali metal such as sodium, potassium or the like, an alkaline earth metal such as calcium, magnesium or the like and an amine such as trialkylamine, pyridine or the like.
The following are examples of the phospholipid- or lipid-linked glycosaminoglycans of the present invention.
A phospholipid-linked glycosaminoglycan represented by the following formula or a salt thereof: ##STR1## wherein P.sup.1 is a phospholipid having a primary amino group and; (1) GAG is located at the 4-position, R.sup.3 is located at the 3-position, R.sup.2 is a COOH group and R.sup.3 is an OH group when GAG is a glycosaminoglycan residue of hyaluronic acid, chondroitin, chondroitin sulfate A, C or E, dermatan sulfate or heparin excluding a reducing terminal glucuronic acid moiety or when GAG is a glycosaminoglycan residue of dermatan sulfate excluding a reducing terminal iduronic acid moiety,
(2) GAG is located at the 4-position, R.sup.3 is located at the 3-position, R.sup.2 is a COOH group and R.sup.3 is an OSO.sub.3 H group when GAG is a glycosaminoglycan residue of chondroitin sulfate K or chondroitin polysulfate excluding a reducing terminal glucuronic acid moiety,
(3) GAG is located at the 3-position, R.sup.3 is located at the 4-position, R.sup.2 is a CH.sub.2 OH group and R.sup.3 is an OH group when GAG is a glycosaminoglycan residue of keratan sulfate excluding a reducing terminal galactose moiety, and
(4) GAG is located at the 3-position, R.sup.3 is located at the 4-position, R.sup.2 is a CH.sub.2 OSO.sub.3 H group and R.sup.3 is an OH group when GAG is a glycosaminoglycan residue of keratan polysulfate excluding a reducing terminal galactose moiety.
A phospholipid-linked glycosaminoglycan represented by the following formula or a salt thereof: ##STR2## wherein P.sup.1 is a phospholipid having a primary amino group and; (1) R.sup.1 is a NHCOCH.sub.3 group and R.sup.3 is an OH group when GAG is a glycosaminoglycan residue of hyaluronic acid or chondroitin excluding a reducing terminal hexosamine moiety,
(2) R.sup.1 is a NHCOCH.sub.3 group and R.sup.3 is an OSO.sub.3 H group when GAG is a glycosaminoglycan residue of chondroitin sulfate A or K, chondroitin polysulfate or dermatan sulfate excluding a reducing terminal hexosamine moiety, and
(3) each of R.sup.1 and R.sup.3 is an OH group when GAG is a glycosaminoglycan residue of keratan sulfate or keratan polysulfate excluding a reducing terminal galactose moiety.
A phospholipid-linked glycosaminoglycan represented by the following formula or a salt thereof: ##STR3## wherein P.sup.1 is a phospholipid having a primary amino group and GAG is a glycosaminoglycan residue of keratan sulfate or keratan polysulfate excluding a reducing terminal galactose moiety.
A phospholipid-linked glycosaminoglycan represented by the following formula or a salt thereof: ##STR4## wherein P.sup.1 is a phospholipid having a primary amino group and; (1) GAG is located at the 4-position, R.sup.3 is located at the 3-position, R.sup.1 is an OH group, R.sup.2 is a COOH group and R.sup.3 is an OH group when GAG is a glycosaminoglycan residue of hyaluronic acid, chondroitin, chondroitin sulfate A, C or E, dermatan sulfate, heparin or heparan sulfate excluding a reducing terminal glucuronic acid moiety or when GAG is a glycosaminoglycan residue of dermatan sulfate excluding a reducing terminal iduronic acid moiety,
(2) GAG is located at the 4-position, R.sup.3 is located at the 3-position, R.sup.1 is an OSO.sub.3 H group, R.sup.2 is a COOH group and R.sup.3 is an OH group when GAG is a glycosaminoglycan residue of chondroitin sulfate D excluding a reducing terminal glucuronic acid moiety or when GAG is a glycosaminoglycan residue of heparin or heparan sulfate excluding a reducing terminal iduronic acid moiety,
(3) GAG is located at the 4-position, R.sup.3 is located at the 3-position, R.sup.1 is an OH group, R.sup.2 is a COOH group and R.sup.3 is an OSO.sub.3 H group when GAG is a glycosaminoglycan residue of chondroitin sulfate K excluding a reducing terminal glucuronic acid moiety,
(4) GAG is located at the 4-position, R.sup.3 is located at the 3-position, at least one of R.sup.1 and R.sup.3 is an OSO.sub.3 H group, while the other is an OH group, and R.sup.2 is a COOH group when GAG is a glycosaminoglycan residue of chondroitin polysulfate excluding a reducing terminal glucuronic acid moiety,
(5) GAG is located at the 3-position, R.sup.3 is located at the 4-position, each of R.sup.1 and R.sup.3 is an OH group and R.sup.2 is a CH.sub.2 OH group when GAG is a glycosaminoglycan residue of keratan sulfate excluding a reducing terminal galactose moiety,
(6) GAG is located at the 3-position, R.sup.3 is located at the 4-position, each of R.sup.1 and R.sup.3 is an OH group and R.sup.2 is a CH.sub.2 OSO.sub.3 H group when GAG is a glycosaminoglycan residue of keratan polysulfate excluding a reducing terminal galactose moiety,
(7) GAG is located at the 3-position, R.sup.3 is located at the 4-position, R.sup.1 is an NHCOCH.sub.3 group, R.sup.2 is a CH.sub.2 OH group and R.sup.3 is an OH group when GAG is a glycosaminoglycan residue of hyaluronic acid or chondroitin excluding a reducing terminal hexosamine moiety,
(8) GAG is located at the 3-position, R.sup.3 is located at the 4-position, R.sup.1 is an NHCOCH.sub.3 group, R.sup.2 is a CH.sub.2 OH group and R.sup.3 is an OSO.sub.3 H group when GAG is a glycosaminoglycan residue of chondroitin sulfate A or K or dermatan sulfate excluding a reducing terminal hexosamine moiety,
(9) GAG is located at the 3-position, R.sup.3 is located at the 4-position, R.sup.1 is an NHCOCH.sub.3 group, R.sup.2 is a CH.sub.2 OSO.sub.3 H group and R.sup.3 is an OH group when GAG is a glycosaminoglycan residue of chondroitin sulfate C or D excluding a reducing terminal hexosamine moiety,
(10) GAG is located at the 3-position, R.sup.3 is located at the 4-position, R.sup.1 is an NHCOCH.sub.3 group, R.sup.2 is a CH.sub.2 OSO.sub.3 H group and R.sup.3 is an OSO.sub.3 H group when GAG is a glycosaminoglycan residue of chondroitin sulfate E excluding a reducing terminal hexosamine moiety,
(11) GAG is located at the 3-position, R.sup.3 is located at the 4-position, R.sup.1 is an NHCOCH.sub.3 group, R.sup.2 is a CH.sub.2 OH group and R.sup.3 is an OSO.sub.3 H group, or R.sup.2 is a CH.sub.2 OSO.sub.3 H group and R.sup.3 is an ON group or an OSO.sub.3 H group, when GAG is a glycosaminoglycan residue of chondroitin polysulfate excluding a reducing terminal hexosamine moiety,
(12) GAG is located at the 4-position, R.sup.3 is located at the 3-position, R.sup.1 is an NHSO.sub.3 H group, R.sup.2 is a CH.sub.2 OSO.sub.3 H group and R.sup.3 is an OH group when GAG is a glycosaminoglycan residue of heparin excluding a reducing terminal hexosamine moiety,
(13) GAG is located at the 4-position, R.sup.3 is located at the 3-position, R.sup.1 is an NHCOCH.sub.3 group or an NHSO.sub.3 H group, R.sup.2 is a CH.sub.2 OH group when R.sup.3 is an OSO.sub.3 H group, or R.sup.2 is a CH.sub.2 OSO.sub.3 H group when R.sup.3 is an OH group or an OSO.sub.3 H group, when GAG is a glycosaminoglycan residue of heparan sulfate excluding a reducing terminal hexosamine moiety,
(14) GAG is located at the 4-position, R.sup.3 is located at the 3-position, R.sup.1 is an NHCOCH.sub.3 group, R.sup.2 is a CH.sub.2 OSO.sub.3 H group and R.sup.3 is an OH group when GAG is a glycosaminoglycan residue of keratan sulfate or keratan polysulfate excluding a reducing terminal hexosamine moiety.
A phospholipid- or lipid-linked glycosaminoglycan represented by the following formula or a salt thereof: ##STR5## wherein P.sup.2 is a phospholipid or a lipid, m is an integer of 1 to 8 and l is an integer of 1 to 10, and;
(1) GAG is located at the 4-position, R.sup.3 is located at the 3-position, R.sup.2 is a COOH group and R.sup.3 is an OH group when GAG is a glycosaminoglycan residue of hyaluronic acid, chondroitin, chondroitin sulfate A, C or E, dermatan sulfate, heparin or heparan sulfate excluding a reducing terminal glucuronic acid moiety or when GAG is a glycosaminoglycan residue of dermatan sulfate excluding a reducing terminal iduronic acid moiety,
(2) GAG is located at the 4-position, R.sup.3 is located at the 3-position, R.sup.2 is a COOH group and R.sup.3 is an OSO.sub.3 H group when GAG is a glycosaminoglycan residue of chondroitin sulfate K or chondroitin polysulfate excluding a reducing terminal glucuronic acid moiety,
(3) GAG is located at the 3-position, R.sup.3 is located at the 4-position, R.sup.2 is a CH.sub.2 OH group and R.sup.3 is an OH group when GAG is a glycosaminoglycan residue of keratan sulfate excluding a reducing terminal galactose moiety, and
(4) GAG is located at the 3-position, R.sup.3 is located at the 4-position, R.sup.2 is a CH.sub.2 OSO.sub.3 H group and R.sup.3 is an OH group when GAG is a glycosaminoglycan residue of keratan polysulfate excluding a reducing terminal galactose moiety.
A phospholipid- or lipid-linked glycosaminoglycan represented by the following formula or a salt thereof: ##STR6## wherein GAG, R.sup.1 and R.sup.3 are as defined in the foregoing formula (II), and m, l and P.sup.2 are as defined in the foregoing formula (V).
A phospholipid- or lipid-linked glycosaminoglycan represented by the following formula or a salt thereof: ##STR7## wherein GAG, R.sup.1, R.sup.2 and R.sup.3 are as defined in the foregoing formula (IV), and m, l and P.sup.2 are as defined in the foregoing formula (V).
A phospholipid-linked glycosaminoglycan represented by the following formula or a salt thereof: ##STR8## wherein P.sup.1 is a phospholipid having a primary amino group and n is an integer not more than the number of carboxyl groups contained in glycosaminoglycan, and;
(1) each of R.sup.1 and R.sup.3 is an OH group when GAG is a glycosaminoglycan chain of hyaluronic acid, chondroitin, chondroitin sulfate A, C or E, or dermatan sulfate,
(2) R.sup.1 is an OSO.sub.3 H group and R.sup.3 is an OH group when GAG is a glycosaminoglycan chain of chondroitin sulfate D,
(2) R.sup.1 is an OH group and R.sup.3 is an OSO.sub.3 H group when GAG is a glycosaminoglycan chain of chondroitin sulfate K,
(4) at least one of R.sup.1 and R.sup.3 is an OSO.sub.3 H group while the other one is an OH group when GAG is a glycosaminoglycan chain of chondroitin polysulfate, and
(5) R.sup.1 is an OH group or an OSO.sub.3 H group and R.sub.3 is an OH group when GAG is a glycosaminoglycan chain of heparin or heparan sulfate.
Preferred molecular weights of the glycosaminoglycans are listed in Table 1.
The phospholipid having a primary amino group represented by P.sup.1 in the foregoing formulae (I), (II), (III), (IV) and (VIII) is a compound represented by the formula: ##STR9## wherein each of R.sup.4 and R.sup.5 is hydrogen, --CH.dbd.CHR.sup.6 or --COR.sup.7 (each of R.sup.6 and R.sup.7 is a C.sub.6-24 alkyl group) and Y is --CH.sub.2 CH.sub.2 NH-- or ##STR10## Particularly preferred are compounds in which either of R.sup.4 and R.sup.5 is a --COR.sup.7 group such as hexadecanoyl or octadecanoyl or in which R.sup.4 is a --CH.dbd.CHR.sup.6 group and R.sup.5 is a --COR.sup.7 group.
The phospholipid or lipid represented by P.sup.2 in the foregoing formulae (V), (VI) and (VII) is a compound represented by the formula: ##STR11## wherein R.sup.8 is hydrogen, R.sup.9 is an alkyl group, R.sup.10 is --CH.dbd.CHR.sup.6 or --COR.sup.7, wherein R.sup.6 and R.sup.7 are the same as above and X is --CH.sub.2 CH.sub.2 N.sup.+ (CH.sub.3).sub.3 or an inositol residue. Particularly preferred are a lipid represented by the formula (X) or (XI) in which either of R.sup.8 and R.sup.9 is a --COR.sup.7 group such as hexadecanoyl or octadecanoyl or in which R.sup.8 is hydrogen and R.sup.9 is a --COR.sup.7 group, or a phospholipid represented by the formula (XII) or (XIII) in which R.sup.10 is a --COR.sup.7 group.
According to the present invention, the aforementioned phospholipid- or lipid-linked glycosaminoglycans are produced by the processes as listed below.
A process for producing a phospholipid-linked glycosaminoglycan represented by the foregoing formula (I) or a salt thereof which comprises the steps of; reducing and cleaving the reducing terminal group of a glycosaminoglycan represented by the formula (I-1) ##STR12## thereby obtaining a reduced product represented by the formula (I-2) ##STR13## oxidizing the reduced product to obtain an oxidized product of the formula (I-3) ##STR14## allowing an aldehyde group in the oxidized product to react with a primary amino group of a phospholipid, wherein GAG, R.sup.2 and R.sup.3 in the formulae (I-1), (I-2) and (I-3), are as defined in the formula (I).
A process for producing a phospholipid-linked glycosaminoglycan represented by the formula (II) or a salt thereof which comprises the steps of;
reducing and cleaving the reducing terminal group of a glycosaminoglycan represented by the formula (II-1) ##STR15## thereby obtaining a reduced product represented by the formula (II-2) ##STR16## oxidizing the reduced product to obtain an oxidized product of the formula (II-3) ##STR17## allowing an aldehyde group in the oxidized product to react with a primary amino group of a phospholipid, wherein GAG, R.sup.1 and R.sup.3 in the formulae (II-1), (II-2) and (II-3), are as defined in the foregoing formula (II) and R is an OH or OSO.sub.3 H group.
A process for producing a phospholipid-linked glycosaminoglycan represented by the formula (III) or a salt thereof which comprises the steps of; oxidizing the reduced product represented by the formula (II-2) to obtain an oxidized product of the formula (11) ##STR18## wherein GAG is as defined in the formula (III), and allowing an aldehyde group in the oxidized product to react with a primary amino group of a phospholipid.
A process for producing a phospholipid-linked glycosaminoglycan represented by the formula (IV) or a salt thereof which comprises the steps of:
oxidizing and cleaving the reducing terminal group of a glycosaminoglycan represented by the formula (12) ##STR19## thereby obtaining an oxidized product represented by the formula (13) ##STR20## lactonizing the oxidized product to obtain a lactone represented by the formula (14) ##STR21## allowing the thus-obtained lactone to react with a primary amino group of a phospholipid, wherein GAG, R.sup.1, R.sup.2 and R.sup.3 in the formulae (12), (13) and (14), are as defined in the formula (IV) and A is an alkali metal,
A process for producing a phospholipid- or lipid-linked glycosaminoglycan represented by the formula (V) or a salt thereof which comprises the steps of;
allowing an aldehyde compound represented by the formula (I-3) to react with an alkylene diamine to obtain a derivative represented by the formula (15) ##STR22## wherein GAG, R.sup.2, R.sup.3 and m are as defined in the formula (V), separately allowing a phospholipid or a lipid to react with a dicarboxylic acid or a dicarboxylic acid anhydride to obtain a phospholipid or lipid derivative having a carboxyl group, and
allowing a primary amino group in the derivative of the formula (15) to react with the carboxyl group in the phospholipid or lipid derivative.
A process for producing a phospholipid- or lipid-linked glycosaminoglycan represented by the formula (VI) or a salt thereof which comprises the steps of;
allowing an aldehyde compound represented by the formula (II-3) to react with an alkylene diamine to obtain a derivative represented by the formula (16) ##STR23## wherein GAG, R.sup.1, R.sup.3 and m are as defined in the formula (VI), separately allowing a phospholipid or a lipid to react with a dicarboxylic acid or a dicarboxylic acid anhydride to obtain a phospholipid or lipid derivative having a carboxyl group, and
allowing a primary amino group in the derivative of the formula (16) to react with the carboxyl group in the phospholipid or lipid derivative.
A process for producing a phospholipid- or lipid-linked glycosaminoglycan represented by the formula (VII) or a salt thereof which comprises the steps of;
allowing a lactone compound represented by the formula (14) to react with an alkylene diamine to obtain a derivative represented by the formula (17) ##STR24## wherein GAG, R.sup.1, R.sup.2, R.sup.3 and m are as defined in the formula (VII),
separately allowing a phospholipid or a lipid to react with a dicarboxylic acid or a dicarboxylic acid anhydride to obtain a phospholipid or lipid derivative having a carboxyl group, and
allowing a primary amino group in the derivative of the formula (17) to react with the carboxyl group in the phospholipid or lipid derivative.
A process for producing a phospholipid-linked glycosaminoglycan represented by the formula (VIII) or a salt thereof which comprises allowing a primary amino group of a phospholipid to react with, in the presence of a condensing agent, a carboxyl group of a glycosaminoglycan represented by the formula (18) ##STR25## wherein GAG, R.sup.1, R.sup.3 and n are as defined in formula (VIII).
A process for producing a phospholipid-linked glycosaminoglycan represented by the formula (VIII) or a salt thereof which comprises the steps of;
activating a carboxyl group of a glycosaminoglycan represented by the formula (18), and
allowing the activated carboxyl group to react with a primary amino group of a phospholipid.
The processes for producing phospholipid- or lipid-linked glycosaminoglycans of the present invention are described in detail below.
Limited oxidation of reducing terminal group
In this process, the reducing terminal uronic acid, galactose or hexosamine moiety of a glycosaminoglycan is partially oxidized and cleaved to form an aldehyde group and the thus-formed aldehyde group is subjected to reductive alkylation reaction with a primary amino group of a phospholipid to give a phospholipid-linked glycosaminoglycan. The reaction scheme of this process is described below.
(A) In the case where glucuronic or iduronic acid in the reducing terminal sugar is subjected to the reaction: ##STR26## wherein R.sup.3 is as defined above and P.sup.1 is a phospholipid having a primary amino group.
In the case of using, as the starting material, hyaluronic acid, chondroitin, chondroitin sulfate A, chondroitin sulfate C, chondroitin sulfate E, chondroitin sulfate K, chondroitin polysulfate, dermatan sulfate and heparin, represented by the formula (1) having the reducing terminal D-glucuronic acid or L-iduronic acid in which an OH group is linked to the 2-position carbon, atom, a phospholipid-linked glycosaminoglycan represented by the formula (I-a) is produced in accordance with the above reaction scheme.
(B) In the case where glucosamine or galactosamine in the reducing terminal sugar is subjected to the reaction: ##STR27## wherein R.sup.3 is as defined above and P.sup.1 is a phospholipid having a primary amino group.
In the case of using, as the starting material, hyaluronic acid, chondroitin, chondroitin sulfate A, chondroitin sulfate K, chondroitin polysulfate and dermatan sulfate, represented by the formula (4) having glucosamine or galactosamine as the reducing terminal group in which a CH.sub.2 OH group is linked to the 5-position carbon atom, a phospholipid-linked glycosaminoglycan represented by the formula (II-a) is produced in accordance with the above reaction scheme.
(C) In the case where galactose in the reducing terminal sugar is subjected to the reaction: ##STR28## wherein R.sup.3 is as defined above and P.sup.1 is a phospholipid having a primary amino group.
In the case of using keratan sulfate and keratan polysulfate represented by the above formula (7); as the starting material having galactose as the reducing terminal sugar, a phospholipid-linked glycosaminoglycan represented by the formula (I-b), (II-b) or (III) is produced in accordance with the above reaction scheme.
In the above processes (A), (B) and (C), the reducing terminal sugar moieties of glycosaminoglycans represented by formulae (1), (4) and (7) are first subjected to reduction cleavage to obtain corresponding compounds (2), (5) and (8).
Usable as a reducing agent in the reduction step is an alkali salt of boron hydride such as sodium boron hydride, sodium cyanoboron hydride or the like.
As a solvent for use in the above reduction reaction, water or a 0.05% borate buffer (pH 8.3) may be used.
The reduction reaction may be effected at a temperature of from 10.degree. to 30.degree. C., preferably from 15.degree. to 25.degree. C.
The amount of the reducing agent, though varying depending on its type, ranges from 5 to 50 equivalents, preferably from 25 to 30 equivalents, per mole of compound (1), (4) or (7).
The thus obtained compounds of formulae (2), (5) and (8) are then subjected to partial oxidation to form aldehyde compounds represented by formulae (3), (6), (9), (10) and (11).
Usable as an oxidation agent in the oxidation reaction is an alkali salt of periodic acid such as sodium periodate, potassium periodate or the like.
The amount of the oxidation agent ranges from 1 to 10 equivalents, preferably from 3 to 6 equivalents, per mole of compound (2), (5) or (8). The oxidation reaction may be effected at a temperature of from 0.degree. to 10.degree. C., preferably from 0.degree. to 4.degree. C.
Each of the thus-formed aldehyde compounds (3), (6), (9), (10) and (11) can be reacted with a primary amino group of a phospholipid in accordance with the known reductive alkylation. Thus, the phospholipid-linked glycosaminoglycans of the present invention represented by the formulae (I-a), (II-a), (I-b), (II-b) and (III) are obtained.
Examples of phospholipids to be used in the above reaction include L-(.alpha.-phosphatidyl)ethanolamine, DL-phosphatidyl-L-serine, ethanolamine plasmalogen, serine plasmalogen and the like.
The reductive alkylation reaction for the production of the compounds represented by the formulae (I-a), (II-a), (I-b), (II-b) and (III) may be effected by mixing the aldehyde compound (3), (6), (9), (10) or (11) and a phospholipid dissolved in chloroform or the like uniformly in a solvent such as water, 0.05M phosphate buffer (pH 7.0) or dimethylformamide and allowing the mixture to react at a temperature of from 15.degree. to 60.degree. C., and simultaneously or thereafter carrying out a reduction reaction using a reducing agent such as sodium cyanoboron hydride or the like.
Examples of compounds which are produced by the limited reducing terminal group oxidation are shown in Table A.
TABLE A______________________________________Com-poundNo. Formula Glycosaminoglycan material______________________________________I-(1) ##STR29## hyaluronic acid, chondroitin, chondroitin sulfate A, C or E, dermatan sulfate, heparin, heaparan sulfateI-(2) ##STR30## chondroitin sulfate K, chondroitin polysulfateI-(3) ##STR31## keratan sulfateI-(4) ##STR32## keratan polysulfateII-(1) ##STR33## hyaluronic acid, chondroitinII-(2) ##STR34## chondroitin sulfate A or K, chondroitin polysulfate, dermatan sulfateII-(3) ##STR35## keratan sulfate, keratan polysulfateIII ##STR36## keratan sulfate, keratan polysulfate______________________________________
Lactonization of reducing terminal group
In this process, the reducing terminal uronic acid, galactose or hexosamine moiety of a glycosaminoglycan is subjected to oxidation to cleave the reducing terminal sugar moiety and the cleaved product is lactonized and reacted with a primary amino group of a phospholipid to obtain a phospholipid-linked glycosaminoglycan. This reaction scheme is illustrated below. ##STR37## wherein each of R.sup.1, R.sup.2 and R.sup.3 is as defined above, P.sup.1 is a phospholipid having a primary amino group and A is an alkali metal.
According to this process, a glycosaminoglycan represented by formula (12) is firstly subjected to oxidation to cleave its reducing terminal moiety, thereby obtaining a carboxyl compound represented by formula (13).
Usable as a starting material are compounds represented by the above formula (12) including hyaluronic acid, chondroitin, chondroitin sulfate A, chondroitin sulfate C, chondroitin sulfate D, chondroitin sulfate E, chondroitin sulfate K, chondroitin polysulfate, dermatan sulfate, heparin, heparan sulfate, keratan sulfate and keratan polysulfate.
Iodine, bromine or the like may be used in the oxidizing step as the oxidation agent.
The amount of the oxidation agent ranges from 2 to 20 equivalents, preferably from 5 to 15 equivalents, per mole of the compound of formula (12).
Water or a 0.05M phosphate buffer (pH 7.0) may be used as the solvent in the oxidation reaction.
The oxidation reaction may be effected at a temperature of from 0.degree. to 40.degree. C., preferably from 15.degree. to 20.degree. C.
The thus obtained compound of the formula (13) is then subjected to acid treatment to form a lactone compound represented by formula (14).
A strongly acidic cation exchange resin such as Dowex 50, Amberlite IR 120 or the like may be used in the acid treatment.
The thus-formed lactone compound of formula (14) is then allowed to react with a phospholipid to produce a phospholipid-linked glycosaminoglycan of the present invention represented by formula (IV).
The same phospholipid compounds as described in the foregoing limited reducing terminal group oxidation process may be used in this reaction step.
The reaction of the lactone compound of formula (14) with a phospholipid for the production of the compound represented by formulae (IV) may be effected by dissolving the lactone compound of formula (14) in a solvent such as water, 0.05M phosphate buffer (pH 7.0) or dimethylformamide, and mixing the solution with a phospholipid dissolved in chloroform or the like uniformly, and allowing the mixture to react at a temperature of from 5.degree. to 80.degree. C., preferably from 30.degree. to 60.degree. C.
Examples of compounds which are produced by the reducing terminal group lactonization process are shown in Table B.
TABLE B__________________________________________________________________________CompoundNo. Formula Glycosaminoglycan material__________________________________________________________________________IV-(1) ##STR38## hyaluronic acid, chondroitin, chondroitin sulfate A, C or E, dermatan sulfate, heparin, heaparan sulfateIV-(2) ##STR39## chondroitin sulfate D, heparin, heparin sulfateIV-(3) ##STR40## chondroitin sulfate KIV-(4)-a ##STR41## chondroitin polysulfateIV-(4)-b ##STR42## chondroitin polysulfateIV-(4)-c ##STR43## chondroitin polysulfateIV-(5) ##STR44## keratan sulfateIV-(6) ##STR45## keratan polysulfateIV-(7) ##STR46## hyaluronic acid, chondroitinIV-(8) ##STR47## chondroitin sulfate A or K, dermantan sulfateIV-(9) ##STR48## chondroitin sulfate C or DIV-(10) ##STR49## chondroitin sulfate EIV-(11)-a ##STR50## chondroitin polysulfateIV-(11)-b ##STR51## chondroitin polysulfateIV-(11)-c ##STR52## chondroitin polysulfateIV-(12) ##STR53## heparinIV-(13)-a ##STR54## heparan sulfateIV-(13)-b ##STR55## heparan sulfateIV-(13)-c ##STR56## heparan sulfateIV-(14) ##STR57## keratan sulfate, keratan polysulfate__________________________________________________________________________
Amidation of reducing terminal group
In this process, each of the aldehyde compounds represented by formulae (3), (6), (9) and (10) and the lactone compound represented by formula (14) is allowed to react with an alkylenediamine compound to obtain a glycosaminoglycan derivative having a primary amino group in its reducing terminal group. The thus-obtained glycosaminoglycan derivative having a primary amino group is then allowed to react with a phospholipid or lipid derivative having carboxyl group such that the primary amino group and the carboxyl group are linked together. Thus, a phospholipid- or lipid-linked glycosaminoglycan is produced. The reaction scheme of this process is illustrated below. ##STR58## wherein each of R.sup.1, R.sup.2 and R.sup.3 is as defined above and P.sup.2 is a phospholipid or a lipid.
A glycosaminoglycan derivative having a primary amino group in its reduction terminus, as represented by the above formula (15), (16) or (17), is obtained by allowing each of compounds (3), (6), (9) and (10) prepared by the aforementioned limited reducing terminal oxidation process, and compound (14) prepared by the aforementioned reducing terminal lactonization process to react with an alkylenediamine compound in the presence of a reducing agent.
An alkylenediamine compound usable in this reaction may be selected from compounds represented by the formula
NH.sub.2 --(CH.sub.2).sub.m --NH.sub.2
wherein m is an integer of from 1 to 8.
Sodium cyanoboron hydride or the like may be used as the reducing agent.
The amount of the reducing agent ranges from 10 to 100 moles per mole of the glycosaminoglycan to be used in the reaction system.
Water or a 0.05M phosphate buffer may be used as the reaction solvent.
The reaction may be effected at a temperature of from 0.degree. to 60.degree. C., preferably from 4.degree. to 25.degree. C.
A phospholipid or lipid derivative having a carboxyl group may be obtained by allowing a phospholipid or lipid compound having a hydroxyl group in its glycerol structure to react with a dicarboxylic acid or a dicarboxylic acid anhydride.
Examples of the phospholipid or lipid compound to be used in this reaction include monoacylglycerol, diacylglycerol, lysophosphatidylcholine, lysophosphatidylinositol, ether lipids, ether phospholipids and the like.
Succinic acid, glutaric acid, adipic acid or the like may be used as the dicarboxylic acid.
Maleic anhydride, succinic anhydride, fumaric anhydride or the like may be used as the dicarboxylic acid anhydride.
1-ethyl-3-(dimethylaminopropyl)carbodiimide, dicyclohexylcarbodiimide or the like may be used as the condensing agent.
Chloroform, acetanilide, dimethylformamide or the like may be used as the reaction solvent.
The reaction temperature may range from 0.degree. to 60.degree. C. when a dicarboxylic acid is used in the presence of a condensing agent, or from 20.degree. to 80.degree. C. when a dicarboxylic acid anhydride is used.
The reaction of a glycosaminoglycan derivative having a primary amino group in its reducing terminal group with a phospholipid or lipid derivative having a carboxyl group may be effected by first activating the carboxyl group in the phospholipid or lipid derivative in accordance with the well known means in the field of peptide chemistry, and then allowing the resulting activated compound to react with the glycosaminoglycan derivative.
Activation of the carboxyl group in the phospholipid or lipid derivative may be effected by converting the carboxyl group into an active ester through reaction of the phospholipid or lipid derivative with N-hydroxysuccinimide, p-nitrophenol, N-hydroxybenzotriazole, N-hydroxypiperidine, N-hydroxysuccinamide, 2,4,5-tri-chlorophenol or the like in the presence of a condensing agent.
Chloroform, acetonitrile, dimethylformamide or the like or a mixture thereof may be used as the reaction solvent. 1-ethyl-3-(dimethylaminopropyl)carbodiimide, dicyclohexylcarbodiimide or the like may be used as the condensing agent.
The reaction may be effected at a temperature of from 0.degree. to 60.degree. C.
The thus-obtained phospholipid or lipid derivative in which the carboxyl group has been activated is then allowed to react with the glycosaminoglycan derivative of formulae (15), (16) or (17) having a primary amino group to obtain the phospholipid or lipid-linked glycosaminoglycans of formulae (V), (VI) and (VII). The solvent used in this reaction is chloroform, acetonitrile, dimethylformamide or a mixture thereof. The reaction temperature ranges from 0.degree. to 60.degree. C.
Illustrative examples of compounds which are produced by the above reducing terminal group amination process are shown in Table C.
TABLE C__________________________________________________________________________(RNH(CH.sub.2).sub.mNHCO(CH.sub.2).sub.lCOP.sup.2)CompoundNo. Formula Glycosaminoglycan material__________________________________________________________________________V-(1) ##STR59## hyaluronic acid, chondroitin, chondroitin sulfate A, C or E, dermatan sulfate, heparin, heaparan sulfateV-(2) ##STR60## chondroitin sulfate K, chondroitin polysulfateV-(3) ##STR61## keratan sulfateV-(4) ##STR62## keratan polysulfateVI-(1) ##STR63## hyaluronic acid, chondroitinVI-(2) ##STR64## chondroitin sulfate A or K, chondroitin polysulfate, dermantan sulfateVI-(3) ##STR65## keratan sulfate keratan polysulfateVII-(1) ##STR66## hyaluronic acid, chondroitin, chondroitin sulfate A, C or E, dermatan sulfate, heparin, heaparan sulfateVII-(2) ##STR67## chondroitin sulfate D, heparin, heparin sulfateVII-(3) ##STR68## chondroitin sulfate KVII-(4)-a ##STR69## chondroitin polysulfateVII-(4)-b ##STR70## chondroitin polysulfateVII-(4)-c ##STR71## chondroitin polysulfateVII-(5) ##STR72## keratan sulfateVII-(6) ##STR73## keratan polysulfateVII-(7) ##STR74## hyaluronic acid, chondroitinVII-(8) ##STR75## chondroitin sulfate A or K, dermantan sulfateVII-(9) ##STR76## chondroitin sulfate C or DVII-(10) ##STR77## chondroitin sulfate EVII-(11)-a ##STR78## chondroitin polysulfateVII-(11)-b ##STR79## chondroitin polysulfateVII-(11)-c ##STR80## chondroitin polysulfateVII-(12) ##STR81## heparinVII-(13)-a ##STR82## heparan sulfateVII-(13)-b ##STR83## heparan sulfateVII-(13)-c ##STR84## heparan sulfateVII-(14) ##STR85## keratan sulfate, keratan polysulfate__________________________________________________________________________
Application of condensing agent
Each member of the glycosaminoglycans, excluding keratan sulfate and keratan polysulfate, contains D-glucuronic acid or L-iduronic acid as the uronic acid moiety, and each of these acids has a carboxyl group linked to its 5-position carbon atom.
In this process, a phospholipid-linked glycosaminoglycan is produced by allowing the uronic acid carboxyl group to react with a primary amino group of a phospholipid in the presence of a condensing agent.
The reaction scheme of this process is illustrated below. ##STR86## wherein each of R.sup.1, R.sup.3, n and P.sup.1 is as defined above.
Compounds represented by formula (18) to be used as the starting material are selected from hyaluronic acid, chondroitin, chondroitin sulfate A, chondroitin sulfate C, chondroitin sulfate D, chondroitin sulfate E, chondroitin sulfate K, chondroitin polysulfate, dermatan sulfate, heparin and heparan sulfate.
Any of the compounds described in the foregoing illustration of the limited reducing terminal group oxidation process may be used as the phospholipid.
Examples of the condensing agent include diethylcarbodiimide, diisopropylcarbodiimide, methylpropylcarbodiimide, dicyclohexylcarbodiimide, hexamethylenecarbodiimide, heptanemethylenecarbodiimide, 1-ethyl-3-(3-dimethylaminopropyl)carbodiimide, 1-cyclohexyl-3-(2-morpholinoethyl)carbodiimide-meso-p-toluenesulfonate, 1-t-butyl-3-(3-dimethylaminopropyl)carbodiimide, diphenylcarbodiimide, 4,4'-dinitrodiphenylcarbodiimide, di-p-tolylcarbodiimide, bis-(trimethylsilyl)carbodiimide and the like.
The condensing agent may be used in an amount of from 10 to 100 moles per mole of a phospholipid or lipid to be used.
The reaction may be effected at a temperature of from 4.degree. to 60.degree. C., preferably from 15.degree. to 25.degree. C., in a solvent such as dimethylformamide, chloroform or a mixture thereof.
Illustrative examples of compounds which are produced by the condensation process are shown in Table D.
TABLE D__________________________________________________________________________CompoundNo. Formula Glycosaminoglycan material__________________________________________________________________________VIII-(1) ##STR87## hyaluronic acid, chondroitin, chondroitin sulfate A, C or E, dermatan sulfateVIII-(2) ##STR88## chrondroitin sulfate DVIII-(3) ##STR89## chondroitin sulfate KVIII-(4)-a ##STR90## chondroitin polysulfateVIII-(4)-b ##STR91## chondroitin polysulfateVIII-(4)-c ##STR92## chondroitin polysulfateVIII-(5)-a ##STR93## heparin, heparan sulfateVIII-(5)-b ##STR94## heparin, heparan sulfate__________________________________________________________________________
Activation of glycosaminoglycan
In this process, similar to the case of the aforementioned condensing agent-applied process, the phospholipid-linked glycosaminoglycan (VIII) is produced by activating the uronic acid carboxyl group and then binding the activated carboxyl group to a primary amino group in a phospholipid.
The same glycosaminoglycan compounds and phospholipid compounds as described in the foregoing condensing agent-applied process may be used in this process.
Activation of the carboxyl group in the uronic acid moiety of a glycosaminoglycan compound may be effected by well known means in the field of peptide chemistry, for example, by converting the carboxyl group into an active ester through reaction of the glycosaminoglycan compound with N-hydroxysuccinimide, p-nitrophenol, N-hydroxybenzotriazole, N-hydroxypiperidine, N-hydroxysuccinamide, 2,4,5-trichlorophenol or the like in the presence of a condensing agent.
The carboxyl group of the uronic acid moiety may be subjected to the reaction as a form of amine salt such as of tri(n-butyl)amine salt, triethylamine salt, pyridine salt or the like.
Dimethylformamide, pyridine, dimethylsulfoxide or the like may be used as the reaction solvent.
1-ethyl-3-(dimethylaminopropyl)carbodiimide, dicyclohexylcarbodiimide or the like may be used as the condensing agent.
The reaction may be effected at a temperature of from 0.degree. to 60.degree. C., preferably from 4.degree. to 20.degree. C.
By allowing the thus obtained carboxyl group-activated glycosaminoglycan to react with a phospholipid, a phospholipid-linked glycosaminoglycan of the formula (VIII) is obtained.
This reaction may be effected by allowing the activated glycosaminoglycan to react with a phospholipid at a temperature of from 0.degree. to 90.degree. C., preferably from 25.degree. to 60.degree. C. in a solvent such as dimethylformamide, chloroform or a mixture thereof.
The contents of phospholipid or lipid portions in the phospholipid- or lipid-linked glycosaminoglycans of the present invention represented by formulae (I) to (VIII) may range from 0.005 to 50%, preferably from 2 to 10%.
Separation and purification of the phospholipid- or lipid-linked glycosaminoglycans obtained by the aforementioned processes may be carried out for instance in the following manner. The final reaction solution in each procedure is mixed with ethanol which has been saturated with sodium acetate and the resulting precipitate is filtered out to remove unreacted phospholipid or lipid. The thus-separated precipitates or subjected to hydrophobic chromatography and the carrier is washed with an aqueous solution of a salt such as ammonium acetate, ammonium chloride, sodium chloride or the like to remove unreacted glycosaminoglycan. Thereafter, the phospholipid- or lipid-linked glycosaminoglycan absorbed to the carrier is eluted with an aqueous solution of 10 to 50% methanol.
The metastasis inhibitor of the present invention may be prepared preferably by mixing each of the phospholipid- or lipid-linked glycosaminoglycans represented by formulae (I) to (VIII), or its pharmacologically acceptable salt, with solid or liquid carriers or diluents for medical use, that is, additive agents such as fillers, stabilizers and the like.
Since the salt form of the phospholipid- or lipid-linked glycosaminoglycan is soluble in water, it is suitable to formulate it into injectable solutions. The amount of the active ingredient in the medical preparation may be varied within the range of from 1 to 90% by weight based on the weight of the carrier.
The active compound may be orally administered in the form of granules, fine granules, powders, tablets, capsules, pills or solutions, as well as bulk powders, or administered by intravenous, intramuscular or subcutaneous injection. The active compound may also be used as external preparations such as suppositories, ointments, cataplasmas, plasters, liniments, lotions and the like. Also, it may be made into powder for injection use which is dissolved in an appropriate liquid upon use.
For the preparation of pharmaceuticals containing the phospholipid- or lipid-linked glycosaminoglycans of the present invention or their salts, any organic or inorganic, and solid or liquid carrier or diluent may be used provided that such additives are acceptable for oral, intestinal, parenteral or topical administration. Carriers to be used in the present invention include water, gelatin, lactose, starch, magnesium stearate, talc, animal and plant oils, benzyl alcohol, gum, polyalkylene glycol, petroleum resins, coconut oil, lanolin and other carriers for medical use. In addition, levels of stabilizers, moistening agents, emulsifying agents, as well as salts for adjusting osmotic pressure or maintaining appropriate pH value of the pharmaceutical preparations.
In the case of granules, fine granules, powders, tablets or capsules, the pharmaceutical preparation may contain the active ingredient of the present invention preferably in an amount of from 5 to 80% by weight, while 1 to 30% by weight may be preferable in the case of solutions. Further, preferred contents of the active ingredient may be in the range of from 1 to 10% by weight in the case of injections, from 1 to 50% by weight in the case of suppositories, and from 0.1 to 10% by weight in the case of ointments, cataplasmas and the like for use in topical administration.
Clinical dose may preferably be in the range of from 100 to 2,000 mg in terms of the amount of the active ingredient per day per adult in the case of oral administration, though the dose may be varied depending on ages and symptoms. Preferably, the above daily dose may be administered once a day or two or three times a day by dividing the dose accordingly.
When used as injections, preferred dose may be in the range of from 100 to 1,000 mg in terms of the amount of the active ingredient per day per adult. When used as ointments, cataplasmas and the like, these preparations with the aforementioned contents of the active ingredient may be applied to an affected part in an appropriate amount.
With regard to acute toxicity of the active ingredient, animal tests were carried out in the following manner. Four-week-old male and female Sic-ddy mice were preliminarily fed for one week and, when the males grew to weigh 23 to 30 g and the females to weigh 20 to 25 g, HA1-PPEADP (lot No. 300) and CS(S3)-PPEADP (lot No. 302-2; both PPEADPs are described later) were dissolved in a physiological saline ordained by The Pharmacopoea of Japan to a concentration of 5% and intraperitoneally administered to the mice. The intraperitoneal administration was applied to this test because of its most frequent generation of the toxicity symptoms. 10 males and 10 females were used in each test group. As a result, it was found that the LD.sub.50 value in each test plot was 2,000 mg/kg or higher, thus proving the safety of the compound of the present invention as a drug.

BRIEF DESCRIPTION OF THE DRAWINGS
FIGS. 1 to 6 show data on the hydrophobic chromatography of phospholipid- or lipid-linked glycosaminoglycans produced in Example 1-(2)-1), Example 2-(2)-1), Example 2-(3), Example 4-(1), Example 5-(1) and Example 5-(2), respectively.

BEST MODE TO PRACTICE THE INVENTION
The present invention is described in detail below with reference to the following Examples which are not construed to limit the scope of the present invention.
In the following examples, contents of phosphorus, phospholipid or lipid and glycosaminoglycan (GAG) in phospholipid- or lipid-linked gylcosaminoglycan were measured in the following manner.
Measuring Method
1. Determination of GAG
(1) GAG containing uronic acid: Carbazole sulfuric acid method (Bitter-Muir method) (Analytical Biochemistry, 4, 330-334, 1962).
(2) Keratan sulfate or keratan polysulfate containing galactose: Anthrone method (Biochem. J., 50, 298-303, 1952).
2. Determination of phospholipid or lipid
(1) Phosphorus: Molybdenum blue method (Inorganic Applied Colorimetric Analysis, vol. 4, pp. 130-135 (representative editor, Shiro Hirano; published by Kyoritsu Shuppan).
(2) Fatty acid: A 10 to 50 mg portion of GAG-lipid is dissolved in 10 ml of 1N sodium hydroxide solution and hydrolyzed at 100.degree. C. for 1 hour. The resulting reaction mixture is adjusted to an acidic pH with 1N hydrochloric acid solution and extracted with chloroform, and the chloroform phase is washed with water. After drying with dehydrated Glauber's salt, the solvent is removed under a reduced pressure. The resulting residue is sealed in a tube together with an appropriate volume of methanol containing 3% HCl (gas), heated at 100.degree. C. for 3 hours and then extracted three times with petroleum ether. The resulting petroleum ether phase is washed three times with water to remove contaminated hydrochloric acid. After drying with Glauber's salt, the resulting product is concentrated under a reduced pressure and subjected to the following gas-liquid chromatography.
Gas-liquid chromatography (GLC)
GC-15A (Shimadzu Corp.)
Loading material: PEG-HT 5% Uniport HP 60/80 (Gasukuro Kogyo Inc.)
Operation condition: gasification chamber, 350.degree. C.
Column temperature: 190.degree. to 200.degree. C.
Column: 3.phi..times.2 m
Flow rate: N.sub.2 45 ml/min
EXAMPLE 1
Preparation of Phospholipid-linked Glycosaminoglycan by Limited Oxidation of Reducing Terminal Group
(1) Preparation of reducing terminal group-limitedly oxidized glycosaminoglycan
1) Preparation of reducing terminal residue-cleaved hyaluronic acid
A 2,000 mg portion of hyaluronic acid (HA1; MW, 10,000; cockscomb origin) was dissolved in 200 ml of 0.05M borate buffer (pH 8.3). After adding 182 mg of sodium boron hydride, the resulting mixture was incubated at room temperature for 5 hours to effect the reaction. The reaction mixture was adjusted to pH 4.5 with acetic acid and then mixed with ethanol to form a precipitate. The thus-obtained precipitate was washed with ethanol to give 1,800 mg of reducing terminal residue-cleaved hyaluronic acid (R-HA1; lot No. 100).
2) Preparation of reducing terminal group-limitedly oxidized hyaluronic acid
A 1,700 mg portion of R-HA1 (lot No. 100) was dissolved in 250 ml of 40 mM imidazole (pH 6.5). After adding 139.96 mg of sodium periodate at 0.degree. C., the resulting mixture was incubated at the same temperature for 1 hour to effect the reaction. Ethanol was added to the reaction mixture to form a precipitate. The thus-obtained precipitate was washed with ethanol to give 1,600 mg of reducing terminal group-limitedly oxidized hyaluronic acid (O-HA; lot No. 200).
3) Preparation of other reducing terminal group-limitedly oxidized glycosaminoglycans (O-GAG)
Reducing terminal residue-cleaved glycosaminoglycans (R-GAG) were prepared according to the above procedure 1) under the conditions shown in Table E, using each of the following starting materials: hyaluronic acid (HA5; MW, 50,000: HA15; MW, 150,000: cockscomb origin), chondroitin (CH; MW, 15,000; sulfuric acid-removed product from chondroitin sulfate A with acidic methanol solution), chondroitin sulfate C (CS (S1); MW, 10,000: CS (S3); MW, 30,000: CS (S6); MW, 60,000: shark cartilage origin), chondroitin sulfate A (CS (W); MW, 30,000: shark cartilage origin), dermatan sulfate (DS; MW, 15,000; swine skin origin), heparin (Hep; MW, 15,000; swine small intestine origin), heparan sulfate (ES; MW, 15,000; bovine kidney origin) and keratan sulfate (KS; MW, 15,000; bovine cornea origin). The thus obtained R-GAG samples were subjected to the above procedure 2) under the conditions shown in Table F to produce reducing terminal group-limitedly oxidized glycosaminoglycans (O-GAG).
TABLE E______________________________________ Reaction condition YieldLot No. Product GAG/NaBH.sub.4 (mg/mg) (mg)______________________________________ 100-2 R-HA5 5000/94.58 4720 100-3 R-HA15 1000/6.31 971101 R-CH 1000/63.05 867102 R-CS (S1) 1000/94.58 880 102-2 R-CS (S3) 1000/31.50 897 102-3 R-CS (S6) 1000/15.76 869103 R-CS (W) 1000/31.50 823104 R-DS 150/9.46 130105 R-Hep 1000/63.05 772106 R-HS 40/2.55 35107 R-KS 20/1.28 14.6______________________________________
TABLE F______________________________________Lot Reaction condition YieldNo. Product R-GAG/NaIO.sub.4 (mg/mg) (mg)______________________________________ 200-2 O-HA5 4500/77.0 4310 200-3 O-HA15 900/5.14 815201 O-CH 800/45.65 766202 O-CS (S1) 800/68.48 715 202-2 O-CS (S3) 800/22.83 774 202-3 O-CS (S6) 800/11.41 699203 O-CS (W) 800/22.83 697204 O-DS 100/5.71 82205 O-Hep 700/39.95 666206 O-HS 30/1.71 22207 O-KS 10/0.57 7______________________________________
(2) Preparation of L-(.alpha.-phosphatidyl)ethanolamine dipalmitoyl-linked glycosaminoglycan (GAG-PPEADP)
1) Preparation of L-(.alpha.-phosphatidyl)ethanolamine dipalmitoyl-linked hyaluronic acid ##STR95##
1,000 mg of lot No. 200 O-HA was dissolved in 100 ml of 0.05M phosphate buffer (pH 7.0) and 69.2 ml of a chloroform/methanol solvent system (2:1) containing L-(.alpha.-phosphatidyl)ethanolamine dipalmitoyl (PPEADP) (1 mg/ml) was added thereto. The resulting mixture was further mixed with methanol to make the mixture into a uniform solution, and the solution was incubated at 50.degree. C. for 1 hour. After adding 25 mg of sodium cyanoboron hydride to the resulting reaction mixture, incubation was continued at 50.degree. C. for 2 hours, followed by concentration under a reduced pressure. To the concentrate was added five volumes of acetic acid-saturated ethanol to form a precipitate and the precipitate was recovered by filtration. The thus-obtained precipitate was dissolved in 0.3M ammonium chloride solution, applied to a hydrophobic chromatographic column (TSK gel Phenyl Toyopearl 650M; 400 ml), washed thoroughly with 0.3 M ammonium chloride solution and then eluted with 30% methanol aqueous solution. The reaction product of interest was found in the 30% methanol fraction, while unreacted HA1 was found in the unabsorbed and washed fractions. The 30% methanol-eluted fraction was concentrated under a reduced pressure, desalted by dialysis and then freeze-dried to obtain white powder of lot No. 300.
Yield: 40 mg
PPEADP content: 6.21%
Hyaluronic acid content: 62.12%
Hydrophobic chromatogram: Shown in FIG. 1
Hydrophobic chromatography was carried out under the following conditions.
Column: TSK gel Phenyl 5 PW (7.5.phi..times.7.5 cm)
Solvent: 0-5 min, 0.3M ammonium chloride solution
5-50 min, 30% methanol solution
Flow rate: 0.5 ml/min
Pressure: 7 kg/0.5 cm.sup.2
Fraction volume: 1 ml/tube
Detection: OD.sub.220 nm
Sample: 100 .mu.l (1 mg/ml solution in 0.3M ammonium chloride)
2) Preparation of other phospholipid-linked glycosaminoglycans
Phospholipid-linked glycosaminoglycans were prepared in accordance with the above procedure (2)-1) from the O-GAG samples shown in Table F and PPEADP under conditions shown in Table G. Results of the analysis of the thus-obtained products are shown in Table G.
TABLE G______________________________________ Reaction condition O-GAG/Lot PPEADP/ Yield PPEADP GAGNo. Product NaBH.sub.3 CN (mg) (%) (%)______________________________________300-2 R-HA5-PPEADP 1000/13.84/5.03 42 1.33 63.43300-3 R-HA15-PPEADP 700/3.23/1.17 35 0.46 63.35301 CH-PPEADP 700/32.29/11.73 30 4.27 59.10302 CS(S1)-PPEADP 700/48.44/17.60 36 5.89 63.04302-2 CS(S3)-PPEADP 700/16.15/5.89 29 2.22 65.52302-3 CS(S6)-PPEADP 500/5.77/2.09 20 1.07 67.13303 CS(W)-PPEADP 500/11.53/4.19 22 2.23 67.48304 DS-PPEADP 50/2.31/0.84 3.7 4.21 66.10305 Hep-PPEADP 500/23.07/8.38 3.8 4.30 74.65306 HS-PPEADP 20/0.92/0.34 3.3 4.09 68.40307 KS-PPEADP 7/0.33/0.12 0.5 3.97 66.24______________________________________
EXAMPLE 2
Preparation of Phospholipid-linked Glycosaminoglycan by Lactonization of Reducing Terminal Group
(1) Preparation of reducing terminal group-oxidized glycosaminoglycan
1) Preparation of reducing terminal group-oxidized hyaluronic acid
500 mg of hyaluronic acid (HA1; MW, 10,000; cockscomb origin) was dissolved in 10 ml of water, and the solution was mixed with 5 ml methanol solution of 0.1M iodine and incubated at room temperature for 6 hours to effect the reaction. To the resulting reaction mixture was added about 5 ml of 0.1N potassium hydroxide to decolor free iodine molecules. Potassium acetate-saturated ethanol was added to the resulting solution to form a precipitate and the precipitated product was collected by filtration, washed thoroughly with ethanol and then dried under a reduced pressure. Thus, 423 mg of reducing terminal group-oxidized hyaluronic acid (lot No. 400) was obtained. Reducing sugar was not detected in the product when checked by Somogyi-Nelson method.
2) Preparation of reducing terminal group-lactonized hyaluronic acid
400 mg of the lot No. 400 reducing terminal group-oxidized hyaluronic acid was dissolved in 10 ml of water, and the solution was passed through 50 ml of a column of a strongly acidic ion exchange resin (Dowex 50(H.sup.+)) spending 1 hour. Thus, a solution containing 390 mg of reducing terminus-lactonized hyaluronic acid was obtained. Reducing sugar was not detected in the solution when checked by Somogyi-Nelson method.
The thus-obtained solution was neutralized with tri-n-butylamine and subsequently freeze-dried to obtain 400 mg of tri-n-butylamine salt of reducing terminus-lactonized hyaluronic acid (lot No. 500).
3) Preparation of other reducing terminus-lactonized glycosaminoglycans
Reducing terminal group-oxidized glycosaminoglycans were prepared according to the above procedure under conditions shown in Table H, using each of the following starting materials: chondroitin (CH; MW, 15,000), chondroitin sulfate C (CS (S1); MW, 10,000: CS (S3); MW, 30,000: and CS (S6); MW, 60,000): dermatan sulfate (DS; MW, 15,000), heparin (Hep; MW, 15,000) and heparan sulfate (HS; MW, 15,000). The thus-obtained samples were subjected to the above procedure 2) under conditions shown in Table I to produce reducing terminal group-lactonized glycosaminoglycans.
TABLE H______________________________________ Reaction conditionLot GAG/0.1M I.sub.2 / Yield Somogyi-No. Product 0.1N KOH (mg/ml/ml) (%) Nelson______________________________________401 CH-COOK 1000/13.4/13.4 828 -402 CS(S1)-COOK 1000/19.8/19.8 901 -402-2 CS(S3)-COOK 1000/3.3/3.3 895 -402-3 CS(S6)-COOK 1000/4.95/4.95 913 -404 DS-COOK 100/0.67/0.67 91 -405 Hep-COOK 1000/6.7/6.7 902 -406 HS-COOK 100/1.34/1.34 88 -______________________________________ *Somogyi-Nelson: presence (+) or absence (-) of reducing sugar determined by SomogyiNelson method.
TABLE I______________________________________ Reaction conditionLot GAG-COOK/ Yield Somogyi-No. Product Dowex 50 (H.sup.+) (mg/ml) (%) Nelson______________________________________501 CH-lactone 800/400 780 -502 CS(S1)-lactone 900/450 805 -502-2 CS(S3)-lactone 800/400 850 -502-3 CS(S6)-lactone 900/450 887 -504 DS-lactone 90/100 96 -505 Hep-lactone 900/400 946 -506 HS-lactone 80/40 72 -______________________________________ *Somogyi-Nelson: presence (+) or absence (-) of reducing sugar determined by SomogyiNelson method.
(2) Preparation of L-(.alpha.-phosphatidyl)ethanolamine dipalmitoyl-linked glycosaminoglycan (GAG-PPEADP)
1) Preparation of L-(.alpha.-phosphatidyl)ethanolamine dipalmitoyl-linked hyaluronic acid ##STR96##
400 mg of lot No. 500 reducing terminus-lactonized hyaluronic acid was dissolved in 200 ml of dimethylformamide and 27.6 mg of PPEADP dissolved in chloroform was added thereto. The resulting mixture was incubated at 70.degree. C. for 2 hours. After removing chloroform from the reaction mixture by distillation, excess volume of sodium acetate aqueous solution was added to the residue to make the reaction product into sodium salt. Sodium acetate-saturated ethanol was added thereto to form a precipitate and the thus-formed precipitate was collected by filtration. The precipitate was dissolved in 0.3M ammonium acetate solution and subjected to purification in accordance with the procedure of Example 1-(2) to obtain 36 mg of the desired product (lot No. 600).
Phosphorus content: 0.30%
PPEADP content: 6.44%
Hyaluronic acid content: 82.37%
Hydrophobic chromatogram: Shown in FIG. 2.
Measuring conditions are the same as described above.
(2) Preparation of other L-(.alpha.-phosphatidyl)ethanolamine dipalmitoyl-linked glycosaminoglycans
These samples were prepared from the reducing terminus-lactonized glycosaminoglycans shown in Table I and PPEADP in accordance with the above procedure (2)-1) under conditions shown in Table J. Results of the analysis of the thus-obtained products are shown in Table K.
TABLE J______________________________________ Reaction conditionLot No. Product GAG-lactone/PPEADP (mg/mg)______________________________________601 CH-PPEADP 700/32.3602 CS(S1)-PPEADP 800/55.4602-2 CS(S3)-PPEADP 400/9.26602-3 CS(S6)-PPEADP 800/9.00604 DS-PPEADP 90/4.15605 Hep-PPEADP 800/36.91606 HS-PPEADP 70/3.31______________________________________
TABLE K______________________________________ Yield PPEADP GAGLot No. Product (mg) (%) (%)______________________________________601 CH-PPEADP 70.2 4.30 90.90602 CS(S1)-PPEADP 88.0 6.41 85.17602-2 CS(S3)-PPEADP 20 2.01 89.70602-3 CS(S6)-PPEADP 56.2 1.08 92.00604 DS-PPEADP 4.5 4.00 90.66605 Hep-PPEADP 24 4.11 90.01606 HS-PPEADP 5.74 4.22 88.21______________________________________
(3) Production of phosphotidylserin stearoylpalmitoyl-linked chondroitin sulfate C ##STR97##
400 mg of lot No. 502-2 reducing terminus-lactonized chondroitin sulfate C was dissolved in 200 ml of diethylformamide and 9 mg of phosphatidylserin stearate palmitate in chloroform was added thereto. The resulting mixture was incubated at 70.degree. C. for 2 hours. After removing chloroform from the reaction mixture by distillation, excess volume of sodium acetate aqueous solution was added to the residue to make the reaction product into sodium salt. Sodium acetate-saturated ethanol was added thereto to form a precipitate and the thus-formed precipitate was collected by filtration. The precipitate was dissolved in 0.3M ammonium chloride solution and then subjected to purification in accordance with the procedure of Example 1-(2) to obtain 20.8 mg of phosphatidylserin stearoylpalmitoyl-linked chondroitin sulfate C (lot No. 700-2).
Phosphorus content: 0.10%
Chondroitin sulfate C content: 86.15%
Hydrophobic chromatogram: Shown in FIG. 3.
Measuring conditions are the same as described above.
EXAMPLE 3
Preparation of Phospholipid- or Lipid-linked Glycosaminoglycan by Amination of Reducing Terminal Group
(1) Preparation of reducing terminal group-aminated glycosaminoglycan
1) Preparation of reducing terminus-aminated chondroitin sulfate C (CS(S3))
100 mg of reducing terminal group-limitedly oxidized chondroitin sulfate C (lot No. 202-2) was dissolved in 50 ml of 0.05M phosphate buffer (pH 7.0), and the solution was mixed with 24 mg of ethylenediamine hydrochloride. After incubating the resulting mixture at 50.degree. C. for 30 minutes, 20 mg of sodium cyanoboron hydride was added to the reaction mixture and the incubation was continued at 50.degree. C. for 2 hours to complete the reaction. Sodium acetate-saturated ethanol was added to the resulting reaction mixture to precipitate the reaction product which was then collected by filtration. The precipitate was dissolved in water and absorbed to 50 ml of DEAE-ion exchange resin, followed by gradient elution with 0.1M-1M sodium chloride aqueous solution. The reducing terminus-aminated chondroitin sulfate C was eluted with 0.4M sodium chloride, while free chondroitin sulfate C was eluted with 0.75M sodium chloride. The 0.4M sodium chloride fraction was desalted by dialysis and then freeze-dried to obtain 80 mg of reducing terminal group-aminated chondroitin sulfate C (lot No. 802-2).
2) Preparation of reducing terminus-aminated heparin (Hep)
The above procedure was repeated except that 100 mg of lot No. 205 reducing terminal group-limitedly oxidized heparin was used. Thus, 77 mg of reducing terminus-aminated heparin (lot No. 805) was obtained.
(2) Preparation of succinic acid derivative of lipid
1) Preparation of succinic acid ester of glycerol monostearate
10.74 g of glycerol monostearate was dissolved in 200 ml of benzene containing 3 ml of pyridine. After adding 6 g of succinic anhydride, the resulting mixture was subjected to reflux for 6 hours. The resulting reaction mixture was concentrated under a reduced pressure, and the precipitate thus formed was subjected to recrystallization from acetone to obtain 8.2 g of succinic acid ester of glycerol monostearate.
2) Preparation of active ester from succinic acid ester of glycerol monostearate with N-hydroxysuccinic acid imide
8 g of the ester obtained in the above procedure 1) was dissolved in benzene, and the solution was mixed with 2 g of N-hydroxysuccinic acid imide and 10 g of dicyclohexylcarbodiimide. After incubating the resulting mixture at room temperature for 20 hours, the reaction mixture was concentrated under a reduced pressure to obtain precipitate of the reaction product. The precipitate was recrystallized from a benzene/n-hexane solvent system to obtain 7.4 g of the desired active ester (lot No. GMS-1).
(3) Preparation of glycerol monostearate-linked chondroitin sulfate C ##STR98##
In 5 ml of water was dissolved 80 mg of the lot No. 802-2 reducing terminus-aminated chondroitin sulfate C. The resulting solution was mixed with 6.95 mg of the lot No. GMS-1 active ester dissolved in dimethylformamide. After incubating the resulting mixture at room temperature for 20 hours, the reaction mixture was mixed with sodium acetate-saturated ethanol to precipitate the reaction product which was subsequently collected by filtration. The thus-collected precipitate was dissolved in 0.3M ammonium chloride aqueous solution and the resulting solution was subjected to purification in the same manner as in the procedure of Example 1-(2)-1) to obtain 38 mg of the desired compound (lot No. 902-2).
Stearic acid content: 0.86%
Chondroitin sulfate C content: 98.2%
(4) Preparation of succinic acid derivative of phospholipid
1) Preparation of succinic acid ester of lysolecithin
In 200 ml of chloroform was dissolved 495 mg of lysolecithin of the following formula. ##STR99## To the resulting solution were added 100 mg of succinic anhydride and 79 mg of pyridine. After incubating the mixture at room temperature for 20 hours, the reaction mixture was concentrated under a reduced pressure to form a precipitate. The thus-formed precipitate was recrystallized from acetone to obtain a succinic acid ester of lysolecithin.
2) Preparation of active ester from succinic acid ester of lysolecithin with N-hydroxysuccinic acid imide
288.5 mg of the ester obtained above was dissolved in dimethylformamide, and the solution was mixed with 57.5 mg of N-hydroxysuccinic acid imide and 103 mg of dicyclohexylcarbodiimide. After incubating the thus-prepared mixture at room temperature for 20 hours, precipitated materials were removed from the resulting reaction mixture to obtain a dimethylformamide solution of the desired active ester.
(5) Preparation of lysolecithin-linked glycosaminoglycan
5) Preparation of lysolecithin-linked chondroitin sulfate C ##STR100##
The dimethylformamide solution of the active ester obtained in the above procedure (4)-2) was mixed with an aqueous solution of 1 g of the lot No. 802-2 reducing terminus-aminated chondroitin sulfate C, and the mixture was incubated at room temperature for 20 hours to effect the reaction. Purification of the reaction product was carried out by hydrophobic chromatography in accordance with the procedure of Example 1.
Yield: 0.52 g
Phosphorus content: 0.105%
Lysolecithin content: 1.96%
Chondroitin sulfate content: 98.04%
Sulfur content: 5.78%
(6) Preparation of glycerol distearate-linked chondroitin sulfate C
An active ester of a succinic acid ester of glycerol distearate was prepared according to the above procedure (2)-2) (lot No. GDS-2). This was allowed to react with reducing terminus-aminated chondroitin sulfate C (lot No. 802-2) obtained in the above procedure (1)-1) in accordance with the above procedure (3), followed by purification. Thus, 27 mg of the desired compound was obtained (lot No. 904).
EXAMPLE 4
Preparation of Phospholipid-linked Glycosaminoglycan Using Condensing Agent
(1) Preparation of L-(.alpha.-phosphatidyl)ethanolamine dipalmitoyl-linked chondroitin sulfate C ##STR101##
400 mg of tri-n-butylamine salt of chondroitin sulfate C (CS(S3)) was dissolved in 100 ml of dimethylformamide. To the resulting solution were added 6.92 mg of PPEADP dissolved in chloroform and 38.4 mg of 1-ethyl-3-(3-dimethylaminopropyl)carbodiimide hydrochloride. The resulting mixture was incubated at room temperature for 20 hours to effect the reaction. After concentrating under a reduced pressure, excess volume of sodium acetate aqueous solution was added to the concentrate to make the reaction product into sodium salt. Ethanol was added thereto to precipitate the salt and the thus-formed precipitate was collected by filtration. The precipitate was dissolved in 0.3M ammonium chloride solution and then subjected to purification in accordance with the procedure of Example 1-(2)-1). Thus, 63 mg of the desired compound (lot No. 1002-2) was obtained.
Phosphorus content: 0.099%
PPEADP content: 2.25%
Chondroitin sulfate C content: 96.61%
Hydrophobic chromatogram: Shown in FIG. 4
Measuring conditions are the same as described above.
(2) Preparation of other L-(.alpha.-phosphatidyl)ethanolamine dipalmitoyl-linked glycosaminoglycans (GAG-PPEADP)
Phospholipid-linked glycosaminoglycans were prepared from various glycosaminoglycans and PPEADP in accordance with the above procedure (1) under conditions shown in Table L. Results of the analysis of the thus-obtained products are shown in Table M.
TABLE L______________________________________ Reaction conditionLot No. Product GAG*.sup.1 /PPEADP/WSC (mg/mg/mg)______________________________________1000 HA1-PPEADP 420/20.76/1031001 CH-PPEADP 420/13.84/68.81002-1 CS(S1)-PPEADP 400/20.76/1031002-3 CS(S6)-PPEADP 400/3.46/17.21003 CS(2)-PPEADP 400/6.92/34.31004 DS-PPEADP 40/1.38/6.881005 Hep-PPEADP 400/13.8/68.81006 HS-PPEADP 13/0.46/2.3______________________________________ *1: trin-butylamine salt
TABLE M______________________________________ Yield PPEADP GAGLot No. Product (mg) (%) (%)______________________________________1000 HA1-PPEADP 28 6.21 90.051001 CH-PPEADP 25.8 4.01 88.641002-1 CS(S1)-PPEADP 51.9 5.28 92.401002-3 CS(S6)-PPEADP 42.2 1.04 97.811003 CS(W)-PPEADP 41.9 2.17 96.621004 DS-PPEADP 29 4.41 89.121005 Hep-PPEADP 101.3 4.04 90.031006 HS-PPEADP 1.2 4.00 88.22______________________________________
EXAMPLE 5
Preparation of Phospholipid-linked Glycosaminoglycan by Glycosaminoglycan-activation Method
(1) Preparation of L-(.alpha.-phosphatidyl)ethanolamine dipalmitoyl-linked chondroitin sulfate C ##STR102##
400 mg of tri-n-butylamine salt of chondroitin sulfate C (CS(S3)) was dissolved in 300 ml of DMF. To the resulting solution were added 9.9 mg of N-hydroxysuccinimide and 20.6 mg of dicyclohexylcarbodiimide. The resulting mixture was incubated at room temperature for 20 hours. Excess volume of sodium acetate aqueous solution was added to the resulting reaction mixture to make the reaction product into sodium salt, followed by the addition of ethanol to collect formed precipitate by filtration. The thus-collected precipitate was immediately dissolved in 30 ml of water, and the solution was mixed with 6.92 g of PPEADP dissolved in chloroform. Dimethylformamide was further added thereto to obtain a uniform solution. After incubating the thus-obtained solution at room temperature for 6 hours, the reaction mixture was concentrated under a reduced pressure and then mixed with acetic acid-saturated ethanol to form a precipitate. Thereafter, the thus-formed precipitate was collected by filtration and dissolved in 0.3M ammonium acetate solution followed by purification in accordance with the procedure of Example 1-(2)-1). Thus, 29.7 mg of the desired compound (lot No. 1102-2) was obtained.
Phosphorus content: 0.100%
PPEADP content: 2.16%
Chondroitin sulfate C content: 95.68%
Hydrophobic chromatogram: Shown in FIG. 5.
Measuring conditions are the same as described above.
(2) Preparation of L-(.alpha.-phosphatidyl)ethanolamine dipalmitoyl-linked chondroitin polysulfate
1 g of tri-n-butylamine salt (sulfur content, 13.0%; molecular weight, 10,000) of chondroitin polysulfate (CSP(II)) was dissolved in 50 ml of dimethylformamide. To the resulting solution were added 1770 mg of N-hydroxysuccinimide and 318 mg of dicyclohexylcarbodiimide. The resulting mixture was incubated overnight at 4.degree. C. Thereafter, 10 ml of water was added to the reaction mixture and the mixture was further allowed to react at room temperature for 15 minutes. After removing formed precipitate, the resulting solution was mixed with 69.2 g of phosphatidyl ethanolamine dipalmitoyl (PPEADP) dissolved in chloroform, and the mixture was allowed to react at room temperature for 6 hours. The resulting reaction mixture was concentrated under a reduced pressure and then mixed with sodium acetate-saturated ethanol to form a precipitate. Thereafter, the thus-formed precipitate was collected by filtration and dissolved in 0.3M ammonium acetate solution, followed by purification in accordance with the procedure of Example 1-(2)-1). Thus, 67 mg of the desired compound (lot No. 1108) was obtained.
Phosphorus content: 0.291%
PPEADP content: 6.5%
Chondroitin polysulfate content: 92.8%
Sulfur content: 12.05%
Hydrophobic chromatogram: Shown in FIG. 6.
Measuring conditions are the same as described above.
EXAMPLE 6
Adhesion of BHK Cells to a Phospholipid- or Lipid-linked Glycosaminoglycan Layer Laminated on Fibronectin-coated Inside Wall of a Culture Dish
Each well of a 96-well incubation plate was coated with 100 .mu.l of 5 .mu.g/ml solution of bovine serum-derived fibronectin. After washing, each well was further coated with 100 .mu.l of each of the phospholipid- or lipid-linked glycosaminoglycans obtained in Examples 1 to 5, with their concentrations shown in Table N.
Separately, BHK cells (new-born hamster kidney cells) cultured in a dish of 100 mm in diameter were treated with 5 ml of 0.1 mg/ml trypsin solution at 37.degree. C. for 5 minutes. To the thus-treated cells was added 5 ml of 1 .mu.g/ml solution of soy bean trypsin inhibitor in order to inactivate trypsin. Thereafter, the thus-separated cells were collected by centrifugation, washed twice and then made into a single cell suspension with a density of 1.times.10.sup.5 cells/ml.
A 100 .mu.l portion of the thus-obtained single cell suspension (1.times.10.sup.4 cells) was poured in each well of the incubation plate which had been double-coated with fibronectin and a phospholipid- or lipid-linked glycosaminoglycan as described above. After incubating at 37.degree. C. for 1 hour, cells which did not adhere were washed out, and the remaining adhered cells were fixed with 2% formaldehyde and observed directly under a phase-contrast microscope to count the number of adhered cells.
Table N shows the concentration-depending changes in the number of adhered cells. Each of the data was expressed in terms of a mean value of three or four measurements. Error (standard deviation) in each experiment is also shown.
When free glycosaminoglycans or unlinked lipids were used instead of the phospholipid- or lipid-linked glycosaminoglycans, they showed no cell adhesion-inhibiting effect even at high concentrations.
TABLE N__________________________________________________________________________Lot No.Sample 302-3 600 601 602 602-2 602-3 CS 604(.mu.g/ml) CS(S6)-PPEADP HA1-PPEADP CH-PPEADP CS(S1)-PPEADP CS(S3)-PPEADP (S6)-PPEADP DS-PPEADP__________________________________________________________________________0.1 98.7% .+-. 0.9% 98.9% .+-. 0.9%0.2 87.4% .+-. 8.8% 82.4% .+-. 3.8% 89.3% .+-. 0.5% 85.8% .+-. 4.6%0.5 89.1% .+-. 15.3% 49.8% .+-. 4.6% 85.0% .+-. l.1% 80.2% .+-. 3.6%1 91.4% .+-. 6.8% 50.2% .+-. 5.2% 44.7% .+-. 6.8% 40.0% .+-. 3.6% -- .+-. --2 60.9% .+-. 4.5% 85.0% .+-. 2.6% 33.5% .+-. 6.9% 35.4% .+-. 9.5% 12.7% .+-. l.0% -- .+-. --5 23.0% .+-. 0.2% 73.5% .+-. 1.3% 81.6% .+-. 6.0% 24.4% .+-. 9.5% 4.3% .+-. 1.3% 1.6% .+-. 0.7% 14.9% .+-. 2.0%10 1.3% .+-. 1.2% 72.5% .+-. 8.8% 80.5% .+-. 6.9% 12.8% .+-. 2.4% 2.8% .+-. 0.4% 1.3% .+-. 0.5% 6.7% .+-. 1.2%20 29.9% .+-. 2.6% 63.8% .+-. 2.7% 3.2% .+-. l.1% 0.7% .+-. 0.1% 0.0% .+-. 0.0% 2.4% .+-. 0.9%50 3.6% .+-. 0.5% 65.5% .+-. 10.0% 0.9% .+-. 0.6%100 0.8% .+-. 0.1% 44.4% .+-. 4.2%200 0.3% .+-. 0.2% 33.8% .+-. 3.8%500__________________________________________________________________________Lot No.Sample 605 606 1000 1002-2 CS 1004 1005(.mu.g/ml) Hep-PPEADP HS-PPEADP HA1-PPEADP (S3)-PPEADP DS-PPEADP Hep-PPEAD__________________________________________________________________________0.10.20.51 88.3% .+-. 16.6%2 86.7% .+-. 1.3% 57.6% .+-. 4.8% 99.3% .+-. 7.8%5 76.1% .+-. 5.4% 14.9% .+-. 0.6% 19.6% .+-. 4.4% 89.9% .+-. 0.4%10 60.5% .+-. 6.9% 5.7% .+-. 0.5% 7.5% .+-. 3.7% 75.6% .+-. 4.9%20 44.0% .+-. 5.0% 2.0% .+-. 0.3% 95.6% .+-. 4.8% 65.0% .+-. 5.7% 95.3% .+-. 0.9%50 46.0% .+-. 7.5% i.3% .+-. 0.4% 80.5% .+-. 5.4% 56.2% .+-. 1.1% 75.0% .+-. 12.1%100 17.3% .+-. 3.4% 1.0% .+-. 0.1% 73.5% .+-. 0.6% 43.7% .+-. 4.9% 55.9% .+-. 1.1%200 11.6% .+-. 2.2% 0.9% .+-. 0.0% 55.0% .+-. 0.3% 45.1% .+-. 1.0%500__________________________________________________________________________
EXAMPLE 7
Effect of Phospholipid- or Lipid-linked Glycosaminoglycan for Inhibiting Cell Adhesion of Various Cultured Cell Lines by Cell Adhesion Substances
The phospholipid- or lipid-linked glycosaminoglycans obtained in Examples 1 to 5 were examined for their effects for inhibiting cell adhesion of various cell lines by cell adhesion substances, using BHK 21 (new-born hamster kidney cell), CEF (arian embryo fibroblast cell), B16F10 (highly metastatic mouse melanoma cell), CHO (Chinese hamster ovarian cell) and baEC (bovine aorta endothelial cell) as the cell lines, and fibronectin (FN), laminin (LN), type I collagen (ColI) and vitronectin (VN) as the cell adhesion substances.
A 5 .mu.g/ml portion of each of fibronectin derived from bovine blood plasma, laminin derived from mouse EHS tumor cell, type I collagen derived from rat thigh and bovine serum-derived vitronectin was coated on a 96-well incubation plate and each of the phospholipid- or lipid-linked glycosaminoglycans obtained in Examples 1 to 5 was further coated in the same manner as in Example 6. Thereafter, a 100 .mu.l portion of a single cell suspension (1.times.10.sup.4 cells) of each of BHK 21, CEF, B16F10, CHO and baEC cells was poured in each well to observe changes in the cell adhesion. As a control, the same procedure was repeated except that the phospholipid- or lipid-linked glycosaminoglycan was not used, and the resulting cell adhesion was expressed as 100%. The results are shown in Table O.
In Table O, relative adhered cell numbers are semi-quantitatively expressed as "-" for no or little adhesion (0 to less than 10%), "+" for 10 to less than 30%, "++" for 30 to less than 50%, "+++" for 50 to less than 70%, "++++" for 70 to less than 90% and "+++++" for 90 to 100% adhesion.
TABLE O__________________________________________________________________________ Cells/cell adhesion substance (5 .mu.g/ml) Amount BHK 21 CEF B16F10 CHOLot No. (.mu.g/ml) FN VN FN VN FN LN FN LN__________________________________________________________________________300(HA1-PPEADP) 10 + 100301(CH-PPEADP) 10 +++++ ++++ 100 +++ +++302(CS(S1)-PPEADP) 10 +++ + ++ 100 ++ - - - - - - -302-2(CS(S3)-PPEADP) 10 - - - - - - - - 100 - - -302-3(CS(S6)-PPEADP) 10 ++ ++ ++ + 100 + + - -303(CS(W)-PPEADP) 10 - - - - - - - - 100 - - - - - - - -304(DS-PPEADP) 10 +++ 100305(Hep-PPEADP) 10 +++++ 100 +++600(HA1-PPEADP) 10 +++ 100601(CH-PPEADP) 10 +++ +++ 100 + +602(CS(S1)-PPEADP) 10 - - 100 - -602-2(CS(S3)-PPEADP) 10 - - - - - - - - 100 - - - - - - - -702-2(CS(S3-P.S) 10 - - - 100 - - -602-3(CS(S6)-PPEADP) 10 - - 100 - -604(DS-PPEADP) 10 - - 100 - -605(Hep-PPEADP) 10 +++ ++ 100 + +606(HS-PPEADP) 10 + + 100 - -902-2(CS(S3)-GMS) 10 +++++ 100 +++904(CS(S3)-GDS) 10 +++ 100 +__________________________________________________________________________ Cells/cell adhesion substance (5 .mu.g/ml) Amount baECLot No. (.mu.g/ml) FN ColI__________________________________________________________________________600(HA1-PPEADP) 10 + ++ 100 - -601(CH-PPEADP) 10 ++++ ++++ 100 ++ ++602(CS(S1)-PPEADP) 10 - + 100 - -602-2(CS(S3)-PPEADP) 10 - - 100 - -602-3(CS(S6)-PPEADP) 10 - - 100 - -604(DS-PPEADP) 10 - ++ 100 - -605(Hep-PPEADP) 10 ++ +++ 100 + ++606(HS-PPEADP) 10 ++ ++ 100 - -HA1 100 +++++ +++++CH 100 +++++ +++++CS(S1) 100 +++++ +++++CS(S3) 100 +++++ +++++CS(S6) 100 +++++ +++++DS 100 +++++ +++++Hep 100 +++++ +++++HS 100 +++++ +++++PPEADP 100 +++++ +++++__________________________________________________________________________ Cells/cell adhesion substance (5 .mu.g/ml) Amount BHK 21 CEF B16F10 CHOLot No. (.mu.g/ml) FN VN FN VN FN LN FN LN__________________________________________________________________________1000(HA1-PPEADP) 10 +++++ 100 ++++1001(CH-PPEADP) 10 +++++ ++++ 100 +++ +++1002(CS(S1)-PPEADP) 10 +++ + ++ 100 ++ - -1002-2(CS(S3)-PPEADP) 10 - - - - - - - - 100 - - - - - - - -1002-3(CS(S6)-PPEADP) 10 ++ ++ 100 + +1003(CS(W)-PPEADP) 10 - - - 100 - - -1004(DS-PPEADP) 10 ++++ 100 ++1005(Hep-PPEADP) 10 +++++ 100 +++1006(HS-PPEADP) 10 ++ 1001108(CPS(II)-PPEADP) 10 +++ 100 +HA1 100 +++++ +++++ +++++ +++++ +++++ +++++ +++++ +++++HA5 100 +++++ +++++ +++++ +++++ +++++ +++++ +++++ +++++HA15 100 +++++ +++++ +++++ +++++ +++++ +++++ +++++ +++++CH 100 +++++ +++++ +++++ +++++ +++++ +++++ +++++ +++++CS(S1) 100 +++++ +++++ +++++ +++++ +++++ +++++ +++++ +++++CS(S3) 100 +++++ +++++ +++++ +++++ +++++ +++++ +++++ +++++CS(S6) 100 +++++ +++++ +++++ +++++ +++++ +++++ +++++ +++++CS(W) 100 +++++ +++++ +++++ +++++ +++++ +++++ +++++ +++++DS 100 +++++ +++++ +++++ +++++ +++++ +++++ +++++ +++++Hep 100 +++++ +++++ +++++ +++++ +++++ +++++ +++++ +++++HS 100 +++++ +++++ +++++ +++++ +++++ +++++ +++++ +++++KS 100 +++++ +++++ +++++ +++++ +++++ +++++ +++++ +++++CPS(II) 100 +++++ +++++ +++++ +++++ +++++ +++++ +++++ +++++PPEADP 100 +++++ +++++ +++++ +++++ +++++ +++++ +++++ +++++__________________________________________________________________________
EXAMPLE 8
Effect of Phospholipid-linked Chondroitin Sulfate C for Inhibiting Adhesion of Highly Metastatic Cancer Cells to Extracellular Matrix of Blood Vessel Endothelial Culture Cells
Mouse blood vessel endothelial cells were cultured in a 24-well incubation plate which had been coated with type I collagen so that the cells grew confluent. Single layer of the cells was treated with 0.5% Triton X-100 at room temperature for 30 minutes, and the thus-disintegrated fragments of the cell layer were washed with Dulbecco's PBS(+) buffer to obtain extracellular matrix of endothelial cells.
Separately, mouse-derived highly metastatic cancer cells (B16F10) cultured in a dish of 100 mm in diameter were treated with 5 ml of a trypsin solution (0.1 mg/ml PBS(-)) at 37.degree. C. for 5 minutes. To the thus-treated cells was added 5 ml of 1 mg/ml solution of soy bean trypsin inhibitor in order to inactivate trypsin. Thereafter, the thus-separated cells were collected by centrifugation, washed twice with a phosphate buffer (PBS (-)) and then made into a single cell suspension (Hanks' BSS--20 mM HEPES, pH 7.4) with a density of 2.times.10.sup.5 cells/ml.
The lot No. 602-2 phospholipid-linked chondroitin sulfate C (CS(S3)-PPEADP) and 500 .mu.l of the thus-prepared single cell suspension of B16F10 (1.times.10.sup.5 cells) were transferred into each well of the aforementioned extracellular matrix-containing 24-well incubation plate and incubated statically at 37.degree. C. for 1 hour in an incubator charged with 5% carbon dioxide.
The supernatant fluid in each well was taken out gently, the residue was washed once gently with Hanks' buffer and both liquid portions were combined. Thereafter, the number of cells in the combined sample was counted using a cell counter (Coulter Electronics) to count cells which did not adhered to the extracellular matrix. A buffer solution containing no lot No. 602-2 compound (no addition) and a buffer containing free chondroitin sulfate C were used as controls.
Adhesion ratio of cells was calculated by subtracting the number of counted unadhered cells from the initially added total cells and dividing the remainder by the number of total cells. The results are shown in Table P.
TABLE P______________________________________Sample Amount added Adhesion ratio______________________________________No addition -- 82.8%Free chondroitin sulfate C 50 .mu.g 82.6%602-2 (CS(S3)-PPEADP) 50 .mu.g 50.7%______________________________________
As is evident from the above results, the phospholipid-linked glycosaminoglycan of the present invention can inhibit adhesion of highly metastatic cancer cells to extracellular matrices of blood vessel endothelial cells, while free chondroitin sulfate C cannot exhibit such an effect.
EXAMPLE 9
Effect of Phospholipid-linked Chondroitin Sulfate C for Inhibiting Metastasis of Highly Metastatic Cancer Cells
Mouse-derived highly metastatic cancer cells (B16F10) cultured in a dish of 100 mm in diameter were treated with 5 ml of an EDTA solution (0.02%/PBS (-)) at 37.degree. C. for 5 minutes, followed by cell separation by pipetting. The cells were collected by centrifugation, washed twice with a phosphate buffer (PBS (-)) and then made into a single cell suspension with a density of 1.times.10.sup.-6 cells/ml. A 0.1 ml portion of this cell suspension (10.sup.5 cells) was mixed with 0.1 ml of a PBS solution of the lot No. 602-2 (CS(S3)-PPEADP) phospholipid-linked glycosaminoglycan (0.1 mg, 1 mg or 5 mg/0.1 ml) and the resulting mixture was administered to C57BL/6 mice through tail vein. Thoracotomy was carried out 2 weeks after the administration to count the number of melanoma colonies metastasized to the surface of the lungs. A buffer solution containing no lot No. 602-2 (CS(S3)-PPEADP) compound (no addition) and a buffer containing free chondroitin sulfate C were used as controls.
Table Q shows the results of counting colonies metastasized to the surface of the lungs per mouse.
TABLE Q______________________________________ Dose ColoniesSample (mg/mouse) (numbers/mouse)______________________________________No addition -- 49.9 .+-. 32.3Free chondroitin sulfate C 5 mg 24.0 .+-. 8.0602-2 (CS(S3)-PPEADP) 0.1 mg 47.2 .+-. 28.1 1 ml 22.0 .+-. 14.8 5 mg 4.0 .+-. 3.5______________________________________
Metastasis of cancer cells was inhibited as the dose of the phospholipid-linked chondroitin sulfate C increased. As is evident from these results, the phospholipid-linked glycosaminoglycan of the present invention can inhibit metastasis of highly metastatic cancer cells. Free chondroitin sulfate C also inhibited the metastasis, but its effect was inferior to that of the phospholipid-linked chondroitin sulfate C (p<0.001).
INDUSTRIAL APPLICABILITY
The phospholipid- or lipid-linked glycosaminoglycans or their salts of the present invention which has cell adhesion-inhibitory activity and has no toxicity are useful as metastasis inhibitors.

Number	Date	Country
2-193816	Jul 1990	JPX
2-193817	Jul 1990	JPX
2-193818	Jul 1990	JPX

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4362737	Schafer et al.	Dec 1982
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5169636	Nanba et al.	Dec 1992
5292509	Hageman	Mar 1994

Number	Date	Country
0114589	Aug 1984	EPX
0198388	Oct 1986	EPX
2492259	Apr 1982	FRX
397650	May 1939	JPX
6117	Jan 1986	JPX
219393	Jan 1990	JPX
258501	Feb 1990	JPX
WO8702777	May 1987	WOX

Metastasis inhibitor composition comprising a phospholipid-linked glycosaminoglycan and method for inhibiting metastasis employing the same

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