Eight new anthraquinone analogues, namely rishirilide E (1), galvaquinones D-F (2-4), and two pairs of enantiomers, galvaquinones G (5a/5b) and H (6a/6b), together with four known compounds, rishirilide B (7), galvaquinone A (8), lupinacidin A (9), and lupinacidin B (10), were obtained from marine-derived Micromonospora sp. SCSIO 07396 by overexpressing the phosphopantetheinyl transferase (PPTase). Based on comprehensive HRESIMS data, NMR spectroscopic analyses, X-ray diffraction, and ECD calculations, their structures and absolute configurations were unambiguously elucidated. Assays for pro-angiogenic and anti-inflammatory effects in zebrafish models combined with cytotoxicity screening against six human cancer cell lines (PANC-1, TE-1, HL60, A549, MDA-MB-231, and GSC0722), showed that 1 and 5b promoted angiogenesis at 20 μM, 4 had moderate anti-inflammatory activity at 20 μM, and 8 exhibited cytotoxic activity against GSC0722 cells, with an IC50 value of 26.4 μM.
Li et al. (Wed,) studied this question.