Chromatography and mass spectroscopy analysis of bioactive principles from Vernonia amygdalina leaf aqueous extract

Abstract

Application of medicinal plants in managing disease conditions is a practice as old as mankind. Its use in today’s healthcare has increased astronomically when compared to any other era. National policies, which integrate herbal products in healthcare systems, and the increasing presence of herbal clinics have become the order in many countries. Despite the ease of accessibility and affordability, the use of products from medicinal plants as phyto-medicines is threatened by the inability to maximize the benefits. This is due to inadequate qualitative and quantitative data necessary for proper application and regulation. Vernonia amygdalina, a herb widely used by ethnics in diverse forms of health management, is one such medicinal plant. This study was designed to determine referenceable values for the ethno formulation of the herb which is usually prepared as the aqueous extract of the leaf. Standard techniques and procedures were employed for this study. Fractionation of the extract was carried out using facilitated column chromatography. Pure principles of fractionates were separated with gas chromatography and identified using hyphenated mass spectrometer based on their relative abundance. The obtained chromatogram and spectra of principles were elucidated by relating data to the Mass Spectral Database with Automatic Mass Spectra Deconvolution & Identification System (AMDIS). Preliminary screening of extract indicated the absence of quinine but presence of alkaloids, tannins and saponins. Aqueous extraction produced 18 % (w/w) yield. The accelerated column chromatography produced a yield in the ratio of four to six to nine for the chloroform, chloroform/methanol and methanol effluents, respectively. Data obtained from the AMDIS elucidation showed the presence of eleven principles, which includes 1, 2, 3, 4-Butanetetrol; 1, 2-Benzenediol; and Caprolactam among others. Some of the properties and bioactivities of these principles have been reported in previous literature. Findings suggest that bioactivity common with some of these principles is consistent with previous literature on the use of the herb, and demonstrates reasons for the folkloric application.