Enzymatic synthesis of amentoflavone glycoside using recombinant oleandomycin glycosyltransferase

Glycosyltransferase (GT) can convert flavonoids, alkaloids, and terpenoids into glycosylated forms. An oleandomycin glycosyltransferase, “OleD” GT from Streptomyces antibioticus was exploited for the glycosylation of amentoflavone. The OleD was functionally expressed in Escherichia coli BL21 (DE3) and purified enzyme was employed as the biocatalyst for the glycosylation of amentoflavone via the transfer of glucose moiety from UDP (uridine diphosphate)-glucose. As a result, amentoflavone monoglycoside was evident in HPLC and LC–ESI-MS spectrometry with an exact mass of 701. In addition, the reaction conditions were optimized with the highest conversion up to 85% at 30min.