Effect of phenolic hydroxyl groups on inhibitory activities of phenylpropanoid glycosides against lipase

Abstract

The phenolic hydroxyl group in polyphenols is a significant structural feature to for understanding their inhibition of lipase. In this paper, we studied four phenylpropanoid glycosides (PPGs) (acteoside, lipedoside A-I, syringalide A 3′-α-l-rhamnopyranoside and osmanthuside B) with different numbers and positions of the phenolic hydroxyl groups in terms of their inhibition of and affinities for porcine pancreatic lipase. The inhibitory effects on lipase were in the order of acteoside (IC50 = 2.17 ± 0.13 mg/ml) > syringalide A 3′-α-l-rhamnopyranoside (IC50 = 3.87 ± 0.21 mg/ml) > lipedoside A-I (IC50 = 4.27 ± 0.22 mg/ml) > osmanthuside B (IC50 = 23.14 ± 0.51 mg/ml). The order of binding affinity to lipase was acteoside > syringalide A 3′-α-l-rhamnopyranoside > lipedoside A-I > osmanthuside B. The hydrogen bond plays an important role in the interaction between PPGs and lipase. With increasing phenolic hydroxyl groups in PPGs, their binding affinities and inhibition for lipase increased.

Keywords

• Phenylpropanoid glycoside
• Lipase inhibition
• Hydroxyl group
• Affinity