Inhibitory Activities on α-Glucosidase and Composition Analysis of Different Fractions of Ethanol Extracts from Actinidia chinensis Radix

Abstract

The inhibitory actions of ethyl acetate, n-butanol and water fractions from Actinidia chinensis Radix (A. chinensis Radix) ethanol extracts on α-glucosidase were investigated. We found that the inhibitory activity of different ethanol extract fractions on α-glucosidase is concentration-dependent. At the same concentration, the ethyl acetate and n-butanol fractions showed higher inhibitory activities on α-glucosidase in comparison with acarbose. We then determined the chemical constituents of the ethyl acetate and n-butanol fractions through ultra performance liquid chromatography-triple-time of flight/mass spectrometry(UPLC-Triple-TOF/MS). Based on the mass spectrometry analysis and the databases Scifinder and Reaxys, 21 compounds(A1—A21) were identified from the ethyl acetate fraction. In addition, 11 of those compounds(A2, A3, A5, A6, A8, A10, A11, A13, A15, A19, A20) were identified for the first time from A. chinensis Radix. We also identified 14 compounds(A22—A32 and A4—A6) from the n-butanol fraction and compound A29 is a new natural product. From the n-butanol fraction, 7 additional compounds (A22, A25, A27, A28, A30—A32) were identified from A chinensis Radix for the first time.