A two-step O- to C-glycosidic bond rearrangement using complementary glycosyltransferase activities.

An efficient 2'-O- to 3'-C-β-d-glucosidic bond rearrangement on the dihydrochalcone phloretin to convert phlorizin into nothofagin was achieved by combining complementary O-glycosyltransferase (OGT) and C-glycosyltransferase (CGT) activities in a one-pot transformation containing catalytic amounts of uridine 5'-diphosphate (UDP). Two separate enzymes or a single engineered dual-specific O/CGT were applied. Overall (quantitative) conversion occurred in two steps via intermediary UDP-glucose and phloretin.

Leloir Glycosyltransferases and Natural Product Glycosylation: Biocatalytic Synthesis of the -Glucoside Nothofagin, a Major Antioxidant of Redbush Herbal Tea.

Nothofagin is a major antioxidant of redbush herbal tea and represents a class of bioactive flavonoid-like -glycosidic natural products. We developed an efficient enzymatic synthesis of nothofagin based on a one-pot coupled glycosyltransferase-catalyzed transformation that involves perfectly selective 3'--β-d-glucosylation of naturally abundant phloretin and applies sucrose as expedient glucosyl donor. -Glucosyltransferase from (rice) was used for phloretin -glucosylation from uridine 5'-diphosphate (UDP)-glucose, which was supplied continuously through conversion of sucrose and UDP catalyzed by sucrose synthase from (soybean).