Claims
- 1. A method for making a peptide having the formula: Ac-.beta.-D-2NAL-(4C1)D-Phe-D-3PAL-Ser-Lys(nicotinoyl)-D-Lys(nicotinoyl)-Leu-Lys(isopropyl)-Pro-D-Ala-NH.sub.2 ; which method comprises (a) forming a first intermediate peptide by solid phase synthesis having the formula: (N.sup..alpha. Boc)-.beta.-D-2-NAL-(4Cl)D-Phe-D-3PAL-Ser(Bz1)-Lys(Fmoc)-D-Lys(Fmoc)-Leu-Lys(2C1Z)-Pro-D-Ala-NH-[resin support], (b) deblocking the N-terminus by removal of Boc; (c) acetylating said deblocked N-terminus with a molar excess of acetic anhydride in dichloromethane; (d) removing said Fmoc protecting groups on said 5-position Lys and 6-position D-Lys; (e) acylating said deprotected amino groups by reacting with a molar excess of nicotinic acid in DMF, using DIIC as a coupling agent, resulting in a second peptide intermediate having the formula: Ac-.beta.-D-2NAL-(4Cl)D-Phe-D-3PAL-Ser)Bz1)-Lys(nicotinoyl)-D-Lys(Nicotinoyl)-Leu-Lys(2C1Z)-Pro-D-Ala-NH-[resin support]; (f) reacting said second intermediate peptide with cyclohexane in the presence of paladium catalyst on charcoal to accomplish phase transfer hydrogenation at the 2C1Z and Bz1 protecting groups; (g) reacting said deprotected second intermediate peptide with acetone in a solution of sodium borate buffer at a pH of about 9 and (h) cleaving said peptide from the resin with HF.
- 2. A method for making a peptide having the formula: Ac-.beta.-D-2NAL-(4C1)D-Phe-D-3PAL-Ser-Lys(nicotinoyl)-D-Lys(nicotinoyl)-Leu-Lys(isopropyl)-Pro-D-Ala-NH.sub.z, which method comprises (a) forming a first intermediate peptide by solid phase synthesis having the formula: (N.sup..alpha. Boc)-.beta.-D-2NAL-(4C1)D-Phe-D-3PAL-Ser(X.sup.3)-Lys(Fmoc)-D-Lys(Fmoc)-Leu-Lys(2C1Z)-Pro-D-Ala-NH-[resin support], wherein X.sup.3 is a protecting group for a hydroxyl group of Ser; (b) initially deblocking the N-terminus by removal of Boc; (c) acetylating said deblocked N-terminus with a molar excess of acetic anhydride; (d) then removing said Fmoc protecting groups on said 5-position Lys and 6-position D-Lys; (e) acylating said deprotected amino groups by reacting with a molar excess of nicotinic acid plus a coupling agent, resulting in a second peptide intermediate having the formula: Ac-.beta.-D-2NAL-(4C1)D-Phe-D-3PAL-Ser(X.sup.3)-Lys(nicotinoyl)-D-Lys(Nicotinoyl)-Leu-Lys(2C1Z)-Pro-D-Ala-NH-[resin support]; (f) deprotecting said second intermediate peptide by reacting with cyclohexane in the presence of palladium catalyst on charcoal to accomplish phase transfer hydrogenation at the 2C1Z and X.sup.3 protecting groups; (g) reacting said deprotected second intermediate peptide with acetone in a solution of sodium borate buffer, and (h) then cleaving said peptide from the resin support with HF.
Government Interests
This invention was made with Government support under Grant No. HD-13527 and Contract Nos. NO1-HD-9-2903 and NO1-HD-0-2906 awarded by the National Institutes of Health. The Government has certain rights in this invention.
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