Identification of compounds from extract methanol of ketepeng leaves (Cassia alata)

Abstract

Cassia alata known as ketepeng is one of traditional herb that has been used as ointment. In Indonesia, its components information has not been much explored yet. The purpose of this research is to characterize one or more compounds from its leaves methanolic extract. C. alata leaves powder was macerated by methanol in room temperature for 24 hours. Chlorophyll and tannin from its leaves methanolic extract were removed by using methanol-water (1:1) and EtOAc, respectively. The EtOAc extract was then fractionated by Liquid Vacuum Chromatography (LVC) by applying gradient elution system of n-hexane-EtOAc and 8 fractions (A-H) were obtained. From B fraction was obtained one of phenolic compounds, methyl p-hydroxybenzoate, has been isolated for the first time from the leaves of this species. The structure of the compound has been established by 1H and 13C NMR spectroscopic methods. Meanwhile from the H fraction was obtained 21 fractions. One of them, the H9 fraction then was analyzed further by using LC-MS and 1H NMR. The chromatogram and 1H NMR spectrum of this fraction still indicated mixture of compound, but a dominant peak at retention time (tR) 6.7 min was observed. Further analysis to this peak, particularly to its mass spectrum, indicated that the peak is predicted as a flavonoid adduct, that is 4’-hydroxy-6-C-xylofuranosyl flavanone.