Efomycine U, a new C 2 -asymmetric elaiophylin derivative from Streptomyces malaysiensis DSM 4137.

Chemical examination of an actinomycete strain DSM 4137 derived from a soil sample derived isolate . DSM 3816, yielded a new -asymmetric elaiophylin derivative efomycine U () and a known analogue halichoblelide D (). These structures were unambiguously elucidated on the basis of extensive NMR spectroscopic and mass spectrometric analyses. All compounds isolated were subjected to antimicrobial, cytotoxic and immnosuppressive activities evaluation.