Regioselective enzymatic acylation of troxerutin in nonaqueous medium

A series of monosubstituted troxerutin esters have been synthesized by enzyme-catalyzed regioselective acylation of troxerutin in nonaqueous medium. Using divinyl dicarboxylates (CH2CHOOC(CH2)nCOOCHCH2, n = 2, 3, 4, 7, 8, 11) featuring different chain length as acyl donors and alkaline protease from Bacillus subtilis as catalyst, troxerutin was regioselective acylated at B’ ethoxyl group. The results indicated that the regioselectivity of the enzyme-catalyzed acylation was not affected by the chain length of the acyl donor.