Fungal biotransformation of tanshinone results in [4+2] cycloaddition with sorbicillinol: evidence for enzyme catalysis and increased antibacterial activity

• DOI: 10.1007/s00253-016-7488-6
• Publication Date: 2016-05-20T05:32:33Z
• Authors: Wenni He; Miaomiao Liu; Xiaolin Li; Xiaoping Zhang; Wael M. Abdel-Mageed; Li Li; Wenzhao Wang; Jingyu Zhang; Jianying Han; Huanqin Dai; Ronald J. Quinn; Hung-wen Liu; Houwei Luo; Lixin Zhang; Xueting Liu
• Keywords: Biotransformation; Hypocrea; Biocatalysis

The biotransformation of tanshinone IIA to a new antibacterial agent tanshisorbicin (1) by the fungus Hypocrea sp. (AS 3.17108) is described. The structure of tanshisorbicin is a hybrid of tanshinone IIA (2) and sorbicillinol (3). The latter is a metabolite produced by Hypocrea sp. The structure of tanshisorbicin was determined using mass spectrometry, NMR spectroscopy, and ECD calculations. The anti-MRSA activity of 1 was found to be significantly higher than that of the parent substrate Tan IIA. Preliminary experiments indicate that tanshisorbicin is formed via a [4+2] cycloaddition reaction that is likely catalyzed by microbial enzyme.