Robinobiosylation of tyrosol by seed meal from Rhamnus cathartica.

Tyrosol robinobioside was prepared under catalysis of robinobiosidase-containing seed meal from common buckthorn Rhamnus cathartica. Robinin, a flavonoid isolated from the flowers of black locust (Robinia pseudoacacia) served as a robinobiosyl donor. The glycosylation proceeded predominantly on the primary hydroxyl of tyrosol, typically yielding mixtures of isomeric glycosides in ratios of 5:1 to 8:1 with overall yields of robinobiosides higher than 20%. This is the first robinobiosylation promoted under enzymatic catalysis. [ABSTRACT FROM AUTHOR]