DE1165605B - Process for the preparation of alkyl esters of the antibiotic BA-163 - Google Patents

Description

Process for the preparation of alkyl esters of the antibiotic BA-163 The invention relates to a process for the preparation of alkyl esters of the antibiotic BA-163. The process according to the invention consists in reacting the antibiotic BA-163 with an alkanol in the presence of an acidic catalyst or for the preparation of the methyl ester with diazomethane in the presence of ether. Suitable acidic catalysts are, for. B. mineral acids, the acid form of a styrene-divinylbenzene cation exchange resin containing sulfonic acid groups, or aromatic sulfonic acids. The antibiotic BA-163 used as starting material is produced according to the method of patent 1089 928 using Streptomyces flocculus ATCC 13257, ATCC 13 535 and ATCC 13 536 or of their mutants or variants by the usual fermentative route under submerged aerobic conditions.

The alkyl esters of the antibiotic BA-163 and especially the methyl esters possess strong therapeutic efficacy and are suitable for treating malignant Tumors in humans and animals. They also fight gram-positive and gram-negative Bacteria. They therefore have many possible uses in human and veterinary medicine, in industry as well as in agriculture. They are also used as disinfectants and for the separation of microorganism mixtures for medical-diagnostic and valuable for scientific purposes.

The methyl ester is in water and the usual organic solvents, like lower alcohols, ethyl acetate and acetone, only slightly soluble and in water Sodium bicarbonate insoluble. An alcoholic ferric chloride test solution is obtained from not colored him. The absorption maxima are when using a KBr bead, that contains 10 / "of the ether (see figure), in the infrared range at the following wavelengths: 3472, 3322, 2933, 2841, 1715, 1689, 1610, 1595, 1555, 1513, 1471, 1443, 1410, 1383, 1351, 1311, 1294, 1230, 1205, 1116, 1089, 1076, 915, 868, 801, 754 cm- '.

The anti-tumor efficacy of the methyl ester of BA-163 is shown in Table I. Table 1 Anti-tumor efficacy of the methyl ester of BA-163 Tumor dose mg / kg number of surviving animals inhibition type 0/0 S-180 2.0 6/6 64 S-180 1.0 6/6 21 S-180 0.5 6/6 29 CA-755 1.5 10/10 97 CA-755 1.0 10/10 95 Average of two attempts CA-755 0.5 10/10 74 Average of two attempts L-1210 1.25 the treated animals survive the control 98 animals by 1.7 times L-1210 0.75 97 L-1210 0.25 98 HS @; . 1 0.8 8/8 86 HS _,: - 1 0.5 8/8 53 HS-: @ 1 0.3 8/8 45 Similar to many carcinostatic agents, the antibiotic BA-163 and its methyl ester are toxic. However, therapeutic doses can be administered without substantial adverse side effects, as illustrated by the data in Table II. White Swiss mice received an injection of 1 cm3 aqueous solution or suspension of the methyl ester of BA-163 for 5 days in a row. The doses administered and the surviving animals are tabulated below. Table 11 Toxicity of the methyl ester of BA-163 Dose Number of surviving animals 20 mg / kg 0/3 15 mg / kg 2/3 10 mg / kg 2/3 The superiority of the methyl ester of BA-163 over the known carcinostatic agents triethylenephosphoramide and triethylenethiophosphoramide is shown in Table III below.

The LD.O of triethylenephosphoramide in mice is 40 mg / kg (Chemical Abstracts, Vol. 55, Col. 7660 f). The LD50 of triethylenethiophosphoramide is 24 mg / kg when administered intraperitoneally to mice and 45 mg / kg when administered orally. In rats, an LD "of 9.4 and 55 mg / kg was found (S 1 ob oda et al., Cancer Chemotherapy Reports, 24 [1962]. Pp. 7 to 17). Table III Dose number of inhibition Surviving tumor type mg / kg animals 9/0 Methyl ester of BA-163 CA-755 5.0 5/6 97 CA-755 3.12 10/10 98 CA-755 2.5 6/6 94 CA-755 1.56 10/10 98 HS- 1 5.0 6/6 92 HS-- 1 5.0 8/8 99 HS - - 1 2.5 7/8 77 Triethylene phosphoramide CA-755 2.0 9/10 '82 CA-755 1.0 10 1/10 78 CA-755 0.5 10/10 36 Triethylenethiophosphoramide HS- 1 3.75 "" 8 91 HS @ 1 2.50 8/8 77 HST 1 1.25 8; '8 29 The following methods described in the literature were used to evaluate the tumors: S-180-Sarcoma 180 (R ei 11 y et al., Cancer Research, Vol. 13 [1953], p. 684). HS-1-Humanes Sarcoma No. 1 (T oo 1 an, op. Cit., Vol. 13 [1953], p. 389). CA-755-Mammary adenocarcinoma 755 (G e 11 Horn et al., Cancer Research, Supplement 3 [1955], p. 38). L-1210 Lymphoid Leukemia 1210 (LW L aw, Journal Nat. Cancer Inst., Vol. 10 [1949], p. 179).

The following examples explain the process according to the invention.

Example 1 A solution of the antibiotic BA-163 in dioxane becomes the diazomethane solution in ether was added in a slight excess. After about an hour Standing at room temperature, the solution is evaporated to dryness. The residue is taken up in methylene chloride and used to remove the unreacted BA-163 washed once with 20/0 aqueous sodium bicarbonate. The methylene chloride layer is washed with water and concentrated to a small volume. After that, the same volume of ether added. The methyl ester crystallizes in the form of gray-brown rectangular plates that melt at 270 to 275 ° C with decomposition. yield 7'1 °,! O.

Example 2 A mixture of the antibiotic BA-163 (1 g), methyl alcohol (25 cm3) and 1 g of a styrene-divinylbenzene cation exchange resin containing sulfonic acid groups is carefully refluxed for about 2 hours. The end of the implementation will be determined by treating a sample with ferric chloride. The absence of one Color reaction shows the completeness of the implementation. The mixture is then filtered and evaporate the filtrate to dryness to give the methyl ester. Additional methyl ester is obtained by extracting the resin with pyridine (30 cm), concentrating of the extract and precipitation of the methyl ester obtained by adding methyl alcohol. Yield 75 0/0.

Both processes given above lead to the same product. It deals is a gray-brown crystalline substance; the one at 270 to 275`C with decomposition melts. i "Zax = 245 or 375 m # t; F = 43,000 or 19,500.

Analysis for C = sH ", O, N .: Found C 59.88V @ p, H 4.75 ° / 0, N 10.51 ° / 0, 0 24.860,! O, methoxyl 23.7711, / 0.

Higher alkyl esters can be prepared in the same way using ethyl, Propyl or butyl alcohol can be obtained in place of methyl alcohol.

Claims (1)

Claim: Process for the production of alkyl esters of the antibiotic BA-163, d u r c h e k e n n -z e i c h n e t that one is the antibiotic BA-163 with an alkanol in the presence of an acidic catalyst or for the preparation of the Reacts methyl ester with diazomethane in the presence of ether.