Galangin (1), 3-O-methylgalangin (2), and galangin flavanone (3), the major bioactive flavonoids isolated from Alpinia officinarum, were biotransformed into one novel and four known metabolites (4–8) by application of the fungal strains Mucor hiemalis and Absidia coerulea as biocatalysts. Their structures were characterized by extensive spectroscopic analyses including one- and twodimensional nuclear magnetic resonance spectroscopy and mass spectrometry. Compounds 1–7 were evaluated for their cytotoxic activities against cancer cell lines using the MTT assay. The new compound 3-O-methylgalangin-7-O-β-D-glucopyranoside (6) exhibited the most potent cytotoxic activity against MCF-7, A375P, B16F10, B16F1, and A549 cancer cell lines with the IC50 values at 3.55–6.23 µM.
Galangin and its derivatives (1–3) were isolated from A. officinarum
and confirmed by NMR in comparison with the standard compounds pur- chased from
Biopurify Phytochemicals Ltd. (Chengdu, China).