A novel pentacyclic indolosesquiterpene, named xiamycin (1), and its methyl ester (2) have been obtained from Streptomyces sp. GT2002/1503, an endophyte from the mangrove plant Bruguiera gymnorrhiza. The structures were established by 1D and 2D NMR, MS, and X-ray crystallography, and the absolute configuration of 1 was elucidated by the modified Mosher method. Compound 1 exhibits selective anti-HIV activity; it specifically blocks R5 but has no effects on X4 tropic HIV-1 infection. In a panel of cytotoxicity assays, compound 2 showed to be more potent (geometric mean IC50 = 10.13 µM) compared to compound 1 (geometric mean IC50 > 30 µM), with antitumor potency being generally less pronounced. Xiamycin represents one of the first examples of indolosesquiterpenes isolated from prokaryotes.
- Natural Products
Ding, L., Muenich, J., Goerls, H., Maier, A., Fiebig, H-H., Lin, W-H., & Hertweck, C. (2010). Xiamycin, a pentacyclic indolosesquiterpene with selective anti-HIV activity from a bacterial mangrove endophyte. Bioorganic & Medicinal Chemistry Letters, 20(22), 6685-6687. https://doi.org/10.1016/j.bmcl.2010.09.010