Novel catechin ester from the leaf extract of Chromolaena Odorata harvested from south eastern Nigeria

Abstract

Nigeria is blessed with abundant number of medicinal plant and most of these plants though used locally, has not been fully  characterized. There is a need to identify the active compounds responsible for the pharmacological activities of these plants extracts.  One such plant is Chromoleana odorata, a plant that grows much in the wild of which every of its parts serves as medicine. Our work is  aimed at isolating and characterizing bioactive compounds from the leaf extract of this plant. The dried leaf sample was extracted with  ethanol, concentrated and re-extracted with chloroform. The extract was partitioned and subjected to column chromatography. The pure  compound was obtained from diethyl ether/ chloroform ( 90;10) ml eluate and was subjected to thin layer chromatography which  showed one spot (Rf 0.36), a yellow oily liquid with a mass of 0.58g. Infra-red absorption (cm^-1 ) showed peaks at 801.378, which is out of  plane aromatic C-H bending, 1095.837, stretching vibration of alcohols and phenols C─O. 1159.202, 1461.116 vibrations for aromatic C=C , 1654.938 aromatic stretching C=C vibrations , 1744.394 for ester C= O and 2855.141, 2922.233, 3365.786 for alcohol OH vibrations . Proton  nuclear magnetic resonance spectroscopy ( 1HNMR) and carbon 13 nuclear magnetic spectroscopy (13CNMR) spectra of compound were  used to elucidate the structure, mass spectrometric analysis gave the mass to charge ratio (m/z) as 346 corresponding to molecular  formula C₁₈H₁₈O₇. The compound was identified as Catechin -7- methoxy methyl ester.