Strepolyketides A-C, three novel SEK15-derived polyketides from Streptomyces sp. HN2A53

Abstract Three novel SEK15-derived polyketides, strepolyketides A-C (1–3), and the known SEK15 (4) were identified from Streptomyces sp. HN2A53. Their structures were established by comprehensive 1D and 2D NMR spectroscopic analysis and HRESIMS data. Compounds 2–3 were the unique dimers of SEK15. Biological evaluation of these compounds showed that compounds 2–4 showed moderate inhibitory activity against influenza virus neuraminidase (NA) in vitro.