YM-266183 and YM-266184, novel thiopeptide antibiotics produced by Bacillus cereus isolated from a marine sponge -: II.: Structure elucidation

YM-266183 and YM-266184 are new antibacterial substances that have activity against drug-resistant bacteria produced by Bacillus cereus QN03323. These structures were elucidated by MS and NMR spectral analysis. YM-266183. and YM-266184 are the cyclic thiopeptides containing thiazole and pyridine moieties, and several unusual amino acids.