Antioxidant Activities, Phenolic and Flavonoid Contents of Methanolic Extract of Stelechocarpus burahol Fruit and its Fractions
Keywords:
Kepel fruit pulp, ABTS, phenolics content, flavonoid content, DPPH.Abstract
Kepel or Stelechocarpus burahol is an exotic fruit originating from Java, Indonesia. This research was
intended to evaluate the antioxidant activities of extracts and fractions of kepel fruit pulp (KFP) based on radical
scavenging capability towards 2,2′-azinobis(3-ethylbenzo thiazoline-6-sulphonic acid) diammonium salt (ABTS) and
2,2′-diphenildiphenyl-1-picrylhydrazil radical (DPPH). In this study, the radical scavenging activities were also
correlated with total phenolics and flavonoid contents. Among the evaluated samples, the ethyl acetate fraction
exhibited the highest antiradical antioxidant activity towards ABTS radical with IC50 of 0.35 μg/ml, lower than that
of vitamin C (as positive control). It also showed highest antiradical activity using DPPH based assay. Methanolic
extract had total phenolic content of 58.28 ± 0.37% wt/wt gallic acid equivalent, higher than its fraction. Meanwhile
the petroleum ether soluble fraction revealed flavonoid content (76.06 ± 11.9%) as rutin equivalent, among the
extract and fractions evaluated. Based on coefficient (R2) values, phenolics and flavonoids contents contributed to
73.09% and 30.99%% towards antiradical scavenging activities, respectively.
