[Hydrolysis of the amidine analogs of penicillins]. / Gidroliz amidinovykh analogov penitsillinov.

The products of the hydrolytic degradation of 6-beta-(hexahydro-IH-azepenyl-1)methylenamino) penicillanic acid, 6-beta-(N,N-dimethylformamidino-N1)-penicillanic acid and 6-beta-(morpholinyl-1)methylenamino penicillanic acid were identified with the method of thin-layer chromatography and paper electrophoresis in neutral, acid and alkaline solutions and in the presence of penicillinase. The data of the study showed that acid hydrolysis of the amidine analogues of penicillins resulted in cleavage of the beta-lactame cycle and formation of the respective penicillanic acids. In the alkaline medium the secondary amine (hexamethylenimine, dimethylamine, morpholine) was cleaved from the antibiotic side chain and the resulting N-formyl-6-aminopenicillanic acid was further cleaved up to peniciec acid. The beta-lactame cycle of the antibiotics was cleaved under the effect of penicillinase and the resulting penicilloinic acids degraded into peniciec acid, N-formylpeniciec acid and secondary amines. In the nutral solution the antibiotics were transformed into N-formyl-6-aminopenicillanic acid and penicilloinic acids at the first stage of the hydrolysis followed by their further degradation with formation of N-formylpeniciec acid, peniciec acid and secondary amines.

[Derivatographic analysis of 6-beta-[(hexahydro-1H-azepin-1-yl) methylenamino]penicillanic acid]. / Derivatograficheskii analiz 6-beta[(geksagidro-1H-azepin-1-il) metilenamino]penitsillanovoi kisloty.

Derivatographic analysis of 5 samples of 6-beta-(hexahydro-IH-azepin-I-yl)methylenamino penicillanic acid was performed. In addition to the antibiotic the samples had water and acetone in their composition. No effects associated with changes in the physical and chemical state of the substance were observed on the derivatogramme of the samples containing 0.2 and 0.8 per cent of water up 140 degrees C. With a further increase in the temperature an exothermic effect was observed with maximum at 152--153 degrees C connected with melting and chemical degradation of the substance. The derivatogrammes of the samples containing 89--96.4 per cent of the antibiotic were characterized by an endothermic effect with minimum at 65 degrees C caused by evaporation of acetone and partially water from them and by an exothermic effect with maximum at 120 degrees C practically not accompanied by any change in the weight resulting from chemical interaction of the antibiotic with water. The study showed sensitivity of 6-beta-(hexahydro-IH-azepin-I-yl)methylenaminopenicillanic acid to the presence of even insignificant amounts of water in it, maximum elimination of which from the antibiotic is an important factor of increasing its stability.

[Stability of the amidine analogs of penicillin and deacetoxycephalosporin to the penicillinase of Bacillus licheniformis 749/c]. / Ustoichivost' amidinovykh analogov penitsillina i dezatsetoksitsefalosporina k penitsillinaze Bacillus licheniformis 749/c

Fermentative hydrolysis of 3 derivatives of 6-beta-amidinopenicillanic acid and I derivative of 7-beta-amidinodeacetoxycephalosporanic acid by penicillinase produced by Bacillus licheniformis 749/c was studied. It was found that 6-beta-[(hexahydro-IH-azepin-I-yl) methyleneamino] penicillanic acid, 6-beta-(N1 N-dimethylformamidino-N1) penicillanic acid and 6-beta [(morpholin-I-yl) methylenemino] penicillanic acid were hydrolyzed by the enzyme 50, 70, and 160 times respectively slower than benzylpenicillin. 7-beta-[(Hexahydro-IH-azepin-I-yl)' methylenemino] deacetoxycephalosporanic acid proved to be at least 10 times more stable to the effect of penicillinase than methicillin. In addition unlike the amidine analogues of penicillin the above compound had an inhibitory effect on penicillinase produced by Bacillus licheniformis 749/c.

[Stability of 6-beta-[(hexahydro-1H-azepin-l-yl)methyleneamino]-penicillanic acid in aqueous solutions]. / Ustoichivost'6-beta[(geksagidro-1H-azepin-l-il)metilenamino]penitsillanovoi kisloty v vodnykh rastvorakh

Stability of acqueous solutions of 6-beta-[(hexahydro-IH-azepin-I-yl)methylenamino] penicillanic acid at various values of pH and temperature was studied. It was found that inactivation of the antibiotic in both the acid and the alkaline medium proceeded according to the equation of the 1st order. At pH 1.3 and a temperature of 35 degrees the half life of the antibiotic was 7 hours. The activation energy calculated according to the Arrenius equation was 13.5 kcal/mol at pH 1.3 and 22.2 kcal/mol at pH 10.5. The antibiotic was inactivated in glycol and phosphate buffers. Its qualitative analysis was performed according to an improved iodometric method.