GC-MS Analysis and Antioxidant Activity of EtOAc Extract Fraction of Acassia sieberiana (Fabaceae) for the Presence of Flavonoids

This research is aimed at analyzing the flavonoid content of ethyl acetate (EtOAc) extract fraction of Acassia sieberiana through Gas chromatography mass spectrometry (GC-MS) and testing its radical scavenging activity on DPPH. The stem bark of the plant was collected from Pankshin local government area of Plateau state. It was made into fine powder and macerated in methanol. The concentrated extract was fractionated in EtOAc and water. The EtOAc fraction was concentrated using rotary evaporator. The concentrated EtOAc extract fraction was subjected into phytochemical screening which revealed the presence of cardiac glycosides, tannins, saponins, flavonoids, phenolic compounds and terpenes. The components of the EtOAc fraction were separated by TLC using solvents mixture of n-hex:EtOAc in the ratio 3:1 and n-hex:EtOAc:MeOH in the ratio 5:1:1. Flavonols, aurones, flavones, flavonones and catechines were indicated. The GC-MS showed the presence of Ergosta–5,22-dien-3-01-acetate(93β,22E), 4H-Benzopyran-4-one,5,6,7-trimethoxy-2-(4-methoxyphenyl), Ethyliso-allocholate, 3,9- epoxypreg-16-en-14-ol-20-one-11,18-diacetoxy-3-methoxy and 10-Octadecnoicacidmethyl ester at retention times  30.038, 31.685, 32.057, 34.148 and 38.780min respectively. The antioxidant activity of the EtOAc extract fraction was appreciable in the sense that it has IC50 of 57.18ug/ml though less than that of ascorbic acid which was found to be 52.04ug/ml.