Structure elucidation and inhibitory effects on human platelet aggregation of chlorogenic acid from Wrightia tinctoria

Abstract

Interest in natural compounds as sources of potentially new treatment options is growing rapidly. Preliminary screening of many different plant extracts showed that Wrightia tinctoria acts as a potent human platelet aggregation inhibitor. The aim of the present study was to isolate and characterize the active compound responsible for potent inhibition of human platelet aggregation in vitro. A 70% ethanolic extract derived from W. tinctoria seeds was fractionated with chloroform followed by ethyl acetate. The ethyl acetate fraction was further fractionated and purified through a series of three successive column chromatographic separations using silica gel, Sephadex LH-20, and C-18 columns. Liquid chromatography coupled to negative electrospray ionization tandem mass spectrometry (LC-MS/MS) and nuclear magnetic resonance (NMR) studies were performed in the structure determination of the active phenolic compound present in the ethyl acetate fraction of W. tinctoria seeds. A phenolic compound has been isolated and identified as chlorogenic acid by LC-MS/MS and NMR studies. Chlorogenic acid showed concentration-dependent inhibitory effect on collagen-induced platelet aggregation in vitro with an IC50 of 0.2363 μg/μl. The present data suggest that chlorogenic acid can be developed as potential antiplatelet agent in the treatment of cardiovascular diseases in diabetes mellitus.