Analysis of bioactive constituents of n-hexane and methanol fractions of Vernonia calvoana Extracts using Gas Chromatography- Mass Spectrometry

Aim: Bioactive constituents of n-hexane and methanol fractions of Vernonia calvoana (VC) leaves were evaluated using Gas chromatography-Mass spectrometry. Method: The leaves were harvested, cleaned and air dried for 7 days. They were ground to yield 5kg weight powder which was macerated and extracted in 8000 mL of 80% ethanol for 48 hours, yielding 310.3g (6.2%) of crude extract after evaporation of the solvent. The paste (251.8g) was subjected to column chromatography over silica gel (mesh 60 – 120μm) and eluted with 1.5L of n-hexane and methanol respectively. The fractions were analyzed for bioactive constituents using Gas chromatography-Mass spectrometry (GC-MS) (30m x 0.25mm ID x 0.25μm film thickness). Result: The results of GC-MS analysis showed the presences of twelve compounds with phytol (46.67%), 8,11,14-eicosatrienoic acid (33.40%), octadecanoic acid (11.25%), pentadecane carboxylic acid (10.69%), 9, 12, 15-octadecatrien-1-ol (8.12%) and ethyl palmitate (7.68%) in the n-hexane fraction, while methanol fraction was observed to have 14 compounds with oleic acid (33.40%), hexadecanoic acid (12.49%), 2-butanone (14.32%), palmitadehyde (8.36%), 11-octadecenoic acid (5.56%), Z-4-nonadecen-1-ol-acetate (5.36%) and limonene Oxide (4.37%) as well as other compounds in trace concentrations. Conclusion: it may be concluded from the results that, extracts of Vernonia calvoana contain various bioactive components that may be exploited as a good source of new drug for pharmaceutical industries.