Iseolides A-C, antifungal macrolides from a coral-derived actinomycete of the genus Streptomyces.

Iseolides A-C (1-3), three new glycosylated macrolides, were identified from the culture extract of Streptomyces sp. DC4-5 isolated from a stony coral Dendrophyllia. Extensive analysis of one- and two-dimensional NMR data, coupled with MS/MS analytical data, revealed that iseolides are new congeners of 36-membered macrolides, PM100117 and PM100118, previously reported from a marine-derived Streptomyces. Iseolides showed potent antifungal activity against a plant pathogen Glomerella cingulata and human pathogens Candida albicans and Trichophyton rubrum with MIC in the range of 0.19-6.25 μg/mL.