9-(P-diethylaminophenyl)-9-chloro-10-phenylacridan agar medium

Abstract

The compound 9-(p-diethylaminophenyl)-9-chloro-10-phenylacridan is a useful antibacterial agent.

Description

This invention is concerned with the chemical compound 9-(p-diethylaminophenyl)-9-chloro-10-phenylacridan. It is a useful antibacterial agent. Its antibacterial spectrum encompasses both Gram-negative and Gram-positive bacteria. Such antibacterial efficacy makes it useful as the active ingredient in compositions designed to inhibit or eradicate bacterial growth. Such compositions include pharmaceutical dosage forms such as creams, ointments, gels, solutions, powders and the like, or it may be incorporated in various objects such as synthetic resins, paints, lacquers and the like to exert a protective effect against bacterial attack or spoilage.

Table I herebelow reflects the antibacterial potency and spectrum of the compound of this invention using the commonly employed serial dilution technique for determining antibacterial activity:

TABLE I______________________________________ANTIBACTERIAL ACTIVITY (MIC) AGAINSTSELECTED MICROORGANISMS BY A SERIALDILUTION METHOD IN BRAIN HEARTINFUSION BROTH Culture MIC*Microorganism Code No. (.mu.g/ml)______________________________________(Gram-Negative Fermentative Bacilli) 34 6.2 54 12.5 63 12.5Enterobacter aerogenes Ae- 67 12.5Enterobacter cloacae 8 25 62 12.5 65 25 66 12.5Escherichia coli 2 0.19 90 0.38 Es- 144 1.5 145 3.1 168 1.5Klebsiella pneumoniae Kl- 20 6.2 23 12.5Proteus mirabilis 91 3.1 92 3.1 112 3.1 113 3.1 115 3.1Proteus morganii Pr- 100 1.5 103 1.5Proteus rettgeri 98 1.5 99 0.75Proteus vulgaris 2 0.75 12 1.5 93 1.5 110 0.75Salmonella cholerae-susi C-104 12.5Salmonella paratypniA A-16 3.1Salmonella pullorum Sa- D-91 12.5Salmonella schotmuelleri B-205 25Salmonella typhi D-13 0.75Salmonella typhimurium B-203 0.75Serratia marcescens Se- 2 3.1 12 6.2Shigella dysenteriaeShigella flexneri Sh- 382 0.38 378 0.38(Gram-Negative Non-FermentativeBacilli)Acinetobacter calcoaceticus Hv- 1 3.1var anitratusAcinetobacter calcoaceticusvar lwoffi Mm- 3 0.024Alcaligenes faecalis Al- 1 6.2 10 100 26 100 44 100 61 100 82 100 86 100 87 100Pseudomonas aeruginosa Ps- 88 50 89 100 90 100 91 50 92 >100 93 100Pseudomonas diminuta 94 0.75(Gram-Variable Bacillus)Haemophilus vaginalis He- 127 0.024(Gram-Positive Cocci)Staphylococcus aureus 12 0.024 246 0.006 253 0.003 256 0.012Staphylococcus cohnii Mi- 252 0.75Staphylococcus epidermidis 247 0.006 249 0.012 262 0.006 263 0.006Streptococcus agalactiae B-86 0.38Streptococcus faecium St- D-37 0.38Streptococcus pyrogenes A-18 0.19(Gram-Positive Bacilli)Bacillus cereus var mycoides Ba- 31 0.048Bacillus subtilis 4 0.024Brevibacterium ammoniagenes Bv- 1 0.012Corynebacterium liquefaciens Co- 11 0.048Corynebacterium xerosis 14 0.38______________________________________ *MIC = Minimal inhibitory concentration

As is evident from Table I above, the bacterial pathogen Pseudomonas aeruginosa is unaffected by realistic dosage amounts of the compound of this invention. Its failure to inhibit this pathogen at such levels is an attribute rather than a detriment, for its ability to inhibit other commonly prevalent bacteria enables it to be used as the active ingredient in a selective medium such as that disclosed in USP XIX when it is desired to detect Pseudomonas aeruginosa to the exclusion of other bacterial species. The ability of the compound of this invention to exert such bacterial selectivity is reflected in Table II herebelow wherein in addition to Pseudomonas aeruginosa less susceptible Enterobacter and Serratia strains are tested:

TABLE II______________________________________EFFECT OF CONCENTRATION ON SELECTIVITYOF BASAL AGAR MEDIUM FOR PSEUDOMONASAERUGINOSA UPON CHALLENGE INOCULATIONWITH SOME NON-PSEUDOMONAO STRAINS ASDETERMINED BY AVERAGECOLONY COUNTS Non- Selective SelectiveTest Culture (.mu.g/ml) Basal Medium TSA.sup.1Microogranism Code No. 20 25 30 Control______________________________________ 10 295 265 308 283 26 117 113 137 128 44 66 69 80 72 61 128 135 124 208 82 91 93 85 148 86 182 169 166 178Pseudomonas aeruginosa Ps- 87 83 86 67 86 88 78 87 57 148 89 102 97 122 93 90 2 2 2 6 91 82 68 59 67 92 176 160 154 125 93 236 227 191 285Enterobacter aerogenes 34 0 83 63 0 0 0 190 67 8 425 Ae-Enterobacter cloacae 8 36 1 296 62 2 0 111 65 0 0 0 95 66 3 0 246Serratia marcescens Se- 2 0 0 128 4 0 0 248 6 0 0 0 181 9 0 0 303 13 ND.sup.2 0.sup.3 213______________________________________ .sup.1 Trypticase Soy Agar .sup.2 Not Done .sup.3 Count from 1 plate

In order that this invention may be readily available to and understood by those skilled in the art, the now preferred method for its preparation is briefly described:

A. Preparation of 9)p-Diethylaminophenyl)-9-Methoxy-10-Phenylacridan

N,N-diphenylanthranilic acid (10 g, 0.0346 mole), diethylaniline (12.3 g, 0.0826 mole) and 100 ml of toluene are placed in a 250 ml three-necked flask fitted with an overhead stirrer, thermometer, dropping funnel and a condenser. Stirring is initiated while phosphorus oxychloride (25 g, 0.1629 mole) is added dropwise over a five-minute period. The reaction temperature rises from 26.degree. C. to 36.degree. C. during the addition of the first 60% of the POCl.sub.3 and drops slowly as the remaining 40% of the POCl.sub.3 is added. The reaction is heated to reflux (108.degree. C.) and held there for three hours.

The solvent and excess POCl.sub.3 is then distilled from the reaction flask until a pot temperature of 140.degree. C. is reached. The total distillate weights 93.8 g.

The pot residue is cooled to 50.degree. C. and 180 ml of anhydrous methanol is added. With cooling 10 g of sodium hydroxide pellets is added. The dark green solution turns purple and then colorless. An additional 3 g of sodium hydroxide pellets is added to completely remove the purple color. The slurry is refluxed for 40 minutes, cooled to 20.degree. C. and the solids collected on a Buchner funnel. The solids are washed with 20 ml of methanol and then reslurried in 150 ml of hot water followed by refiltering. The filter cake is washed with hot water, cold water and then with 20 ml of cold methanol. The product is air-dried to give 12.0 g (80% yield) of 9-(p-diethylaminophenyl)-9-methoxy-10-phenylacridan.

B. Preparation of 9(p-Diethylaminophenyl)-9-Chloro-10-Phenylacridan

9(p-Diethylaminophenyl)-9-methoxy-10-phenylacridan (12.0 g, 0.0276 mole) is slurried in 150 ml of tetrahydrofuran while anhydrous hydrogen chloride is bubbled in with cooling. The hydrogen chloride is bubbled in until the slurry reaches a pH of 1.0 and a bright yellow color is obtained. The product is collected on a Buchner funnel, washed twice with 10 ml portions of tetrahydrofuran and dried at 50.degree. C. to give 11.6 g (95.8% yield) of 9(p-diethylaminophenyl)-9-chloro-10-phenylacridan.

Claims

1. An agar medium for the selective isolation of Pseudomonas aeruginosa from other bacterial species containing 30 .mu.g./ml. of 9-(p-diethylaminophenyl)-9-chloro-10-phenylacridan.