The structures of A10255 B, -G and -J: new thiopeptide antibiotics produced by Streptomyces gardneri

The structures of the major members of a new family of important thiopeptide antibiotics, A10255B (1), A10255G (15), and A10255J (16), produced by Streptomyces gardneri (NRRL 15537), are described. Selective chemical degradation in combination with NMR, FABMS, and CID methods on the degradation products was required to solve these structures. Methanolysis of 1 resulted in the isolation of 4-carbomethoxy-2-propionyloxazole (8) and dimethyl sulfomycinamate (9) as well as N-((acetamidomethyl)thiazolyl)-1-(carbomethoxythiazolyl)ethanamide (11) after acetylation