Purification and isolation of components of Vernonia amygdalina extracts demonstrating antioxidant activity and flavonoid content

Antioxidants are known to demonstrate anti-carcinogenic, anti-inflammatory and cardio-protective activities as a result of their ability to quench free radicals. Previous studies have shown that antioxidant compounds contain phenols. Previous studies have also shown that Vernonia amygdalina (VA) possess antioxidant activity, as well as phenols and flavonoids. The goal of my project was to purify components of extracts of VA and isolate the components that showed activity. The dried samples of VA were ground, and extracted with methanol, acetone, ethyl acetate, dichloromethane and hexanes. The extracts were then dried under reduced pressure using a rotary evaporator. Purification processes that were employed included both silica- gel and alumina flash column chromatography. The eluents were collected while running solvents such as hexanes, ethyl acetate, and methanol in series of fractions. The eluents were then examined using thin layer chromatography, for specific regions of activity. Silica gel and Alumina are the two most widely used adsorbents in thin layer and column chromatography because they are insoluble in most mobile phases and because their polarity aids in the separation of molecules of solutes to be separated. The various isolated components of VA were then analyzed by infra-red (IR) spectroscopy and nuclear magnetic resonance (NMR) spectroscopy to determine their composition