Three New Depsipeptides, Homiamides A-C, Isolated from Streptomyces sp., ROA-065

Three new depsipeptides, homiamides A-C ( - ), were isolated from a marine sediment-derived strain of sp., ROA-065. The planar structures of homiamides A-C ( - ) were elucidated using mass spectrometry (MS) and nuclear magnetic resonance (NMR) spectroscopic data. The absolute configurations of - were deduced from the application of the Marfey's method and GC-MS analysis after formation of the -trifluoroacetylated ( )-(+)-methyl-2-butyl ester derivatives of amino acids. Compounds - exhibited weak anti-bacterial activities against both Gram-positive bacteria and Gram-negative bacteria, with compound showing MIC values of 32-64 μg/mL. In antifouling assays, compounds and displayed moderate activity against KCTC 3063, while compound exhibited weak activity against all tested bacteria.