Synthesis of long chain fatty acids acylated coumarin glycoside esters with lipase as catalyst

Abstract

A series of novel coumarin glycoside esters(1—9) was synthesized through the acylation reaction of 4-methylcoumarin-7-O-β-D-glucoside(11) with different long chain fatty acids catalyzed by lipase in organic medium. The acylation occurred regioselectively at the 6′-OH of glycosyl moiety. The enzymatic synthesis was optimized to achieve 54%—70% yield using immobilized lipase(Novozym 435, 10 mg/mL) as catalyst and acetone and pyridine( 9:1, volume ratio, water content<1%) as solvent with an acyl donor/coumarin glycoside molar ratio of 10:1 at a temperature of 40—50 °C for 96 h. All the synthesized compounds were confirmed.