Nitro derivatives and other compounds from sugar apple (Annona squamosa L.) leaves exhibit soluble epoxide hydrolase inhibitory activity

Abstract

A phytochemical study for the MeOH extract of Annona squamosa leaves led to the isolation of seven compounds. Among them there were two nitro derivative compounds (1 and 2), two phenolic glucoside compounds (3 and 4), and three sesquiterpenes (5‒7). The structures of these natural compounds were determined by the spectroscopic methods including 1D and 2D NMR methods. All the isolated compounds were assessed for the effects on the sEH inhibitory activity; of all the compounds, thalictoside (1) and arabinothalictoside (2) displayed strong inhibition of sEH activities with IC50 value of 20.2 µM and 47.1 µM, respectively. A kinetic analysis of compounds 1 and 2 revealed that both of them were competitive inhibitory action. The molecular docking increases our understanding of receptor‒ligand binding of all compounds. These results suggested that nitro derivatives from Annona squamosa leaves are potential sEH inhibitors.