Glycosylation of (–)-maackiain by Beauveria bassiana and Cunninghamella echinulata var. elegans
(–)-Maackiain (1) was transformed by Beauveria bassiana and Cunninghamella echinulata var. elegans to yield a new methylglycosylation product, (–)-maackiain-3-O-(4′-O-methyl-β-D-glucopyranoside) (2, 90%) and known trifolirhizin (3, 16%). The kinetics of the two glycosylation reactions was investigated. Additionally, 3 was converted to 2 via 4′-methylation by B. bassiana, which implied that the 4′-methylglycosylation mechanism of (–)-maackiain by B. bassiana is glycosylation followed by methylation. The antioxidant, antifungal, cytotoxic and DNA topoisomerase I inhibition bioactivities of 1, 2 and 3 were tested. Compounds 2 and 3 showed in vitro cytotoxicity against a leukemia cell line (HL-60) with GI50 at 56.3±9.5 and 46.5±5.2 µM, respectively. However, the cytoxicity of 1 was measured as GI50>100 µM.
Yuan, Wei; Wang, Ping; Zhang, Zhizhen; and Li, Shiyou, "Glycosylation of (–)-maackiain by Beauveria bassiana and Cunninghamella echinulata var. elegans" (2010). NCPC Publications and Patents. 43.