Phytochemical screening and GC-FID identification of bioactive compounds in n-hexane, ethylacetate and methanol fractions of methanolic leaves extract of Azanza garckeana

Abstract

Azanza garckeana is a tropical African plant commonly used for food and medicine. This study was aimed at evaluating the antioxidant, phytochemicals and the bioactive compounds present in n-hexane, ethylacetate and methanol fractions of the methanolic extract of Azanza garckeana leaves. Phytochemical screening and antioxidant assayed were carried out using standard methods, while bioactive compounds were analyzed using gas chromatography-flame ionization detector (GC-FID). The phytochemical compositions revealed considerable level of tannins and saponins with moderate concentration of flavonoids and steroids in the methanol fraction; whereas n-hexane fraction also showed considerable amount of tannins followed by saponins and a low concentration of steroids. However, ethylacetate fraction had the highest yield of tannins, steroids, and terpenoids which were significantly (p < 0.05) higher than methanolic fraction and n-hexane fraction respectively. The antioxidant activity of the methanolic crude extract of A. garckeana leaves showed that the % DPPH radical scavenging activity of the crude extract increased with decreased in concentration when compared with the standard antioxidant (ascorbic acid). The result of GC-FID analysis revealed the presence of nineteen constituents in n-hexane fraction, while ethylacetate and methanol fractions each have twenty constituents. This result showed that Azanza garckeana leaves contain health-promoting bioactive compounds with potent antioxidants.