Four new pentalenic acid metabolites from the genetically engineered strain Streptomyces avermitilis HU02.

Four previously undescribed pentalenic acid metabolites, 2-hydroxymethylpentalenic acid (1), 9-hydroxypentalenic acid (2), 3-hydroxypentalenic acid (3) and pentalenene-10, 13-dioic acid (4) along with pentalenic acid (5), were isolated from cultures of the genetically manipulated strain Streptomyces avermitilis HU02. Their planar structures and absolute configurations were unambiguously established by comprehensive HRESIMS, NMR, and ECD spectroscopic analyses.