Enzymatic production of oroxylin A and hispidulin using a liverwort flavone 6‐O‐methyltransferase

• Published in: FEBS letters Vol. 590; no. 16; pp. 2619 - 2628
• Main Authors: Zhang, Yu‐Ying, Xu, Rui‐Xue, Gao, Shuai, Cheng, Ai‐Xia
• Format: Journal Article
• Language: English
• Published: England 01.08.2016
• Subjects: Apigenin - chemistry; baicalein; Cerebrovascular Disorders - drug therapy; Cloning, Molecular; Flavanones - chemistry; Flavones - biosynthesis; Flavones - chemistry; Flavones - therapeutic use; Flavonoids - biosynthesis; Flavonoids - chemistry; Flavonoids - therapeutic use; Hepatophyta - chemistry; Hepatophyta - enzymology; Humans; liverworts; Methyltransferases - chemistry; Methyltransferases - genetics; Methyltransferases - isolation & purification; O‐methyltransferase; Plagiochasma appendiculatum; scutellarein; Substrate Specificity; O-methyltransferase; Plagiochasma appendiculatum; baicalein; scutellarein; liverworts
• ISSN: 0014-5793; 1873-3468
• DOI: 10.1002/1873-3468.12312

Oroxylin A and hispidulin, compounds which are abundant in both Scutellaria and liverwort species, are important lead compounds for the treatment of ischemic cerebrovascular disease. Their enzymatic synthesis requires an O‐methyltransferase able to interact with the related flavonoid's 6‐OH group, but such an enzyme has yet to be identified in plants. Here, the gene encoding an O‐methyltransferase (designated PaF6OMT) was isolated from the liverwort species Plagiochasma appendiculatum. A test of alternative substrates revealed that its strongest preferences were baicalein and scutellarein, which were converted into, respectively, oroxylin A and hispidulin. Allowed a sufficient reaction time, the conversion rate of these two substrates was, respectively, 90% and 100%. PaF6OMT offers an enzymatic route to the synthesis of oroxylin A and hispidulin.