DOI: 10.1021/acs.orglett.6c04374 ISSN: 1523-7060
Okgyeamides A–C: Cyclic Pentapeptides with Distinct Tyr–Trp C–C and C–N Cross-Links from a Cave-Derived Streptomyces sp.
Ran Hui Kim, Sunhee Park, Shinae Park, Yong-Joon Cho, Yeon Hee Ban, Munhyung BaeAbstract
Okgyeamides A–C (1–3), cyclic pentapeptides with a YPWIP sequence and distinct Tyr–Trp C–C and C–N cross-links, were isolated from cave-derived Streptomyces sp. SOG2–3 KCTC19252P. Their structures were characterized by NMR, HRESIMS, advanced Marfey’s and GITC analyses, DP4+ calculations, and ECD analysis. Genome analysis identified a candidate precursor–P450 locus, okgA–okgB, consistent with a ribosomal origin. Okgyeamide A (1) showed ABTS radical-scavenging activity under the conditions tested.