Phosphonomycin is a newly discovered antibiotic produced by streptomycetes. It is effective, when administered by the oral route, to mice infected with Gram-positive or Gram-negative microorganisms. The antibiotic is bactericidal and inhibits cell-wall synthesis.
A new //-lactam antibiotic, named thienamycin, was discovered in culture broths of Streptomyces MA4297. The producing organism, subsequently determined to be a hitherto unrecognized species, is designated Streptomyces cattleya (NRRL 8057). The antibiotic was isolated by adsorption on Dowex 50, passage through Dowex 1, further chromatography on Dowex 50 and Bio-Gel P2, and final purification and desalting on XAD-2. Thienamycin is zwitterionic, has the elemental composition CuHIGN2O4S (M.W.=272.18) and possesses a distinctive UV absorption (Amax=297 nm, e=7,900). Its /3-lactam is unusually sensitive to hydrolysis above pH 8 and to reaction with nucleophiles such as hydroxylamine, cysteine and, to a lesser degree, the primary amine of the antibiotic itself. The latter reaction results in accelerated inactivation at high antibiotic concentrations. * This report was presented in part at the 16th Interscience Conference on Antimicrobial Agents and Chemotherapy, Chicago, Ill., 1976 (q. v. abstract #227) ** This antibiotic is the first representative of a family of des-thia-carbapenem nucleus antibiotics in which the enamine portion of the fused 5-member ring bears a thioethylamine moiety. From this structural feature , the name thienamycin (thi'en-a-mi'san) is derived. THE JOURNAL OF ANTIBIOTICS JAN.
jugular vein without the subsequent shocking dose of egg albumin. The latter 5 animals showed no ill effect of the intravenous injection. The results are given in Table I. Autopsy of the fatalities disclosed typical pulmonary edema and emphysema in 17 of the controls, while in 2 animals the emphysema was patchy, and in one animal gross lesions were absent. In the fatalities of the histaminase group, findings typical of anaphylaxis were present in 18 of the animals, while in the remaining one, emphysematous blebs were present.The first experiment involving a small group in which the administration of histamine apparently effected a survival rate of 1000/0, was very promising and appeared to confirm the findings of Karady and Browne. However, subsequent experiments involving a total number of animals more than 3% times as great as that used by the above workers failed to show any effect of the histaminase preparations on anaphylactic shock of guinea pigs. The results were negative when the histaminase preparations were injected intravenously or intraabdominally.Conclusion. The protective action of histaminase on anaphylactic shock of guinea pigs as reported by Karady and Browne could not be confirmed.
Discussion.
CHLOROPEPTINS I AND II, NOVEL INHIBITORS AGAINST gpl20-CD4 BINDING FROM Streptomyces sp. Sir: Recently, we reported the first gpl20-CD4 binding inhibitors of microbial origin, isochromophilones I and II, produced by Penicillium sp.1}. Now, we report additional two gpl20-CD4 binding inhibitors, chloropeptins 1(1) and ll(2) (Fig. 1), produced by a soil actinomycete, Streptomyces sp. WK-3419. The major component 1 is a new compound, while the other one 2 was identified with complestatin2) which has been reported to inhibit the hemolysis of erythrocytes sensitized by the complement system3). This communication deals with the fermentation, isolation, characterization
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