Abstract

PHYTOCHEMICAL ANALYSIS AND IN VITRO ENZYME INHIBITORY ACTIVITY ESSAY OF EUPHORBIA HIRTA LINN. EXTRACTS

Minh Tran, Ngan Tran, Han Truong, Ly Le*

ABSTRACT

In this study, in vitro analysis of on α-amylase and α-glucosidase inhibitory activity, total phenolic content (TPC), total flavonoid content (TFC) and phytochemical analysis of three different extracts (petroleum ether extract, chloroform extract and ethyl acetate extract) from crude extract of Euphorbia hirta Linn. (E.hirta) were determined using spectrophotometer and Fourier-transform infrared spectroscopy (FTIR) methods. α-amylase and α-glucosidase inhibitory activity of extracts were expressed as percentage of inhibition and IC50 values. Value in percentage of standard acarbose, crude, petroleum ether extract, chloroform extract and ethyl acetate extract at a concentration 10mg/ml were 94.69%, 55.06%, 16.55% and 40.97% inhibitory effects on α-amylase. Percentage inhibition of α-glucosidase at a concentration 10mg/ml were 54.91%, 76.67% and 98.39% presence for standard acarbose, crude extract and ethyl acetate extract in which petroleum ether extract and chloroform extract did not show inhibitory effects on α-glucosidase. Total phenolic content value of crude extract, petroleum ether extract, chloroform extract and ethyl acetate extract were 194.55 ± 0.82, 51.85 ± 3.12, 81.56 ± 1.72 and 214.21±2.53 mg of GAE/ g extract, expressed as gallic acid equivalents. Crude extract, petroleum ether extract, chloroform extract and ethyl acetate extracts showed total flavonoids 40.56 ± 7.27, 29.49± 1.66, 64.99 ± 2.60 and 91.69± 1.67 mg of RU/g extract, as rutin equivalents. FTIR spectra analysis of four extracts were comparable and showed the presence of alkaloids, saponins, polyphenols, terpenoids, steroids, flavonoids, quinones and terpenes. Two bioactive compounds that are 5-methoxybenzene-1,2,3-triol and 2-(2,4-dihydroxyphenyl)-3,6-dihydroxy-8-methoxy-4H-chromen-4-one were identified in ethyl acetate extracts by using column chromatography method, thin layer chromatography (TLC) and NMR spectroscopy.

Keywords: Euphorbia hirta Linn., total phenolic content (TPC), total flavonoid content (TFC), ?-amylase, ?-glucosidase.