Bioassay- guided Isolation of New Urease Inhibitory Constituents from Monotheca buxifolia (Falc.) Fruit and Their Molecular Docking Studies

The aim of the study is to explore the inhibitory potential of extract/fractions, and compounds of Monotheca buxifolia fruit against urease enzyme. Crude hydro-ethanolic extract showed a mild inhibitory activity against urease, among fractions ethylacetate fraction was more active followed by n-butanol fraction while there was no inhibitory activity in n-hexane soluble fraction. Ethylacetate fraction was subjected to activity guided isolation yielding four pure compounds, among them two were new i.e. buxifoline-A (1) (First time isolated from natural sources) and buxilide (2) while the other two were first time isolated from the fruit that are isoquercetin (3)and oleanolic acid ­(4). Their structures were elucidated using spectroscopic and spectrometric techniques. Among the isolated compounds compound 3 showed maximum inhibition. In order to understand the binding interactions of the compound 3, it was docked into the active site of urease enzyme. Our study validates the traditional use of the fruit in the treatment of gastritis and urinary tract infections, which is strongly supported by the isolated compound isoquercetin (3).