A novel type of non-enzymatic reaction during the late steps in the biosynthesis of the angucycline antibiotics urdamycins C and D
作者:J�rgen Rohr
DOI:10.1039/c39900000113
日期:——
Investigations on the latesteps in the biosynthesis of the urdamycin complex showed the surprising result that the interconversion of urdamycin A (1) into the urdamycinsC (2) and D (3) are due to non-enzymatic condensations of (1) with 4-hydroxyphenylpyruvic acid and indole-3-pyruvic acid, respectively.
Biosynthetic formation of the S-methyl group of the angucycline antibiotic urdamycin E
作者:J�rgen Rohr
DOI:10.1039/c39890000492
日期:——
Biosynthetic studies on the angucyclineantibioticurdamycinE (1), produced by Streptomyces fradiae(strain Tü 2717), resulted in methionine being the precursor of the S-methylgroup which is transfered in a unique way as an intact unit from methionine thus showing a new structural element biogenetically deriving from this amino acid; the discussed mechanism for this unusual reaction is an enzymatic
Three new antibiotics were obtained from the culture filtrate of an actinomycete identified as Streptomyces violaceolatus, and were named kerriamycins A, B and C, respectively. The structures of these kerriamycins were elucidated by NMR spectral analysis and chemical degradation, which revealed that each kerriamycin was composed of a common chromophore identified as aquayamycin and two or three mols of hexoses. The kerriamycins inhibited the growth of Gram-positive bacteria and prolonged the survival periods of mice bearing Ehrlich ascites carcinoma.