| 摘要 |
A new antibiotic, thermothiocin, active against gram-positive bacteria, is produced by cultivating a thermothiocin-producing strain of Thermoactinopolyspora coremialis ATCC 15974 in an aqueous nutrient medium containing a soluble carbon source, assimilable nitrogen and sulphur sources and essential mineral salts under submerged aerobic conditions and recovering the accumulated antibiotic from the fermentation broth. Preferably, the cultivation takes place in an aqueous nutrient medium having a pH from 5 to 10.5 at a temperature from 35 DEG to 60 DEG C. for a period of 8 to 55 hours. The antibiotic may be recovered by filtering the medium, extracting the filtrate with EtAc, adjusting the pH to 3 and extracting with butanol and recovering thermothiocin from the butanol extract, e.g. by concentrating and cooling to precipitate thermothiocin. The crude material may be purified by treatment with methanol. Thermothiocin is an amorphous yellow powder having M.pt. at 300 DEG C.; containing C46.01; H 7.14%; N 14.5%; S 6.21%; O 26.14%; COCH3 3.05%; OCH3 absent; having an equivalent weight of 1500; giving an approximate empirical formula of C60H110N16O25S3 it is polypeptic in nature and on strong acid hydrolysis the amino acids glycine, cysteine, aspartic acid, methionine, lysine, g -aminobutyric acid, alanine, phenylalanine and proline are produced; it is soluble in dimethylformamide, pyridine and dioxane; slightly soluble in aqueous media at pH 7 and higher and alkanols with 1 to 5 carbon atoms inclusive; insoluble in aqueous media at pH lower than 7, EtAc, chloroform, benzene, acetone and ethyl ether; has a specific rotatory power [alpha]25D+29.4 (C 0.5% dimethylformamide); showing an U.V. absorption shoulder at 275 mm in dimethylformamide and I.R. absorption at the following frequencies (Nujol, Trade Mark) 3350, 1665, 1515, 1410, 1290, 1122, 1072, 961, 890, 876, 845, 794, 720 and 697 cm.-1.
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