BIOLOGICAL ACTIVITY AND MASS SPECTROMETRIC ANALYSIS OF Vernonia amygdalina FRACTIONS

Vernonia amygdalina (VA) is a tropical African plant of the Asteraceae family used as dietary supplement and as a medicinal herb. In this study, fatty acid esters, fatty acid amide, triterpene, diterpene alcohols and phytostanols were identified as the major chemical groups in the aqueous and organic fractions of VA leaf extracts. Their structures were elucidated, on the basis of GC-MS data, as hexanedioic acid, bis (2-ethylhexyl) ester (2a), erucamide (2b) and squalene (2c) in the water fraction; hexadecanoic acid methyl ester (3a), 9(Z)12(Z)15(Z)-octadecatrienoic acid, methyl ester (3b) and phytol (3c) in methanol fraction; phytol (4a), squalene (4b) and 7,22-ergostadienol (4c) in the petroleum ether fraction. Diterpene alcohol and aliphatic acid esters were higher in relative content than triterpene, fatty acid amide, and phytostanol in VA leaf extracts. In vitro evaluation of anti-proliferative activities of sample extracts on MDA-MB-231 cells revealed significant growth inhibition by methanol (45-70%, P \u3c 0.001) and petroleum ether (70-97%, P \u3c 0.001) fractions, compared to aqueous fraction (11-23%, P \u3c 0.05)