Asian Journal
Of Traditional Medicines

Abstract: Microbial transformation is a useful tool for structure modification of active natural products. Z-Butylidenephthalide is the main active constituent of Angelica sinensis. In the present work, a pair of new oxidized metabolites, namely (–) (11R)-(Z)-11-hydroxybutylidenephthalide (1a) and (+) (11S)-(Z)-11-hydroxy-butylidenephthalide (1b), were obtained from microbial transformation for region-selective 11-hydroxylation of Z-butylidenephthalide by Aspergillus niger CGMCC 3.739. Their structures, including absolute configurations, were elucidated by extensive analysis of HR-ESI-MS, NMR spectra, and the modified Mosher’s method. This is the first study on the microbial transformation of Z-butylidenephthalide, and these findings offer a tool for region-selective 11-hydroxylation of Z-butylidenephthalide.

Key words: microbial transformation, Z-butylidenephthalide, Aspergillus niger CGMCC 3.739, region-selective hydroxylation