title: Metabolic products of microorganisms. 228. New nikkomycins produced by mutants of Streptomyces tendae.
abstract: Four new dipeptidyl nikkomycins of the Z- and the X-series with a variation in the amino acid moiety of the molecule were isolated from the mutant Streptomyces tendae 901/395 and characterized. Nikkomycins Kz and Kx contain 2-amino-4-hydroxy-4-(2-pyridyl)butyric acid, and nikkomycins Oz and Ox 2-amino-4-hydroxy-4-(5-hydroxy-2-pyridyl)butyric acid. In contrast to nikkomycins Z and X, nikkomycins Kx and Ox are quite stable at alkaline pH and exhibit a lower biological activity against various test organisms. From the mutant S. tendae 901/C37, which is auxotrophic for methionine and threonine, enhanced amounts of two tripeptidyl nikkomycins, Qz and Qx, were produced which are analogues of nikkomycins J and I and contain a homoserine residue instead of glutamic acid. These nikkomycins exhibit a high pH instability.
mesh_terms: D000617:Aminoglycosides; D000900:Anti-Bacterial Agents; D000935:Antifungal Agents / Q000096:biosynthesis* / Q000494:pharmacology; D002687:Chitin Synthase / Q000037:antagonists & inhibitors; D002851:Chromatography, High Pressure Liquid; D006863:Hydrogen-Ion Concentration; D009154:Mutation; D009705:Nucleosides / Q000096:biosynthesis / Q000494:pharmacology; D013302:Streptomyces / Q000235:genetics / Q000378:metabolism*
chemical_list: D000617:Aminoglycosides; D000900:Anti-Bacterial Agents; D000935:Antifungal Agents; D009705:Nucleosides; C011952:nikkomycin; D002687:Chitin Synthase