Antioxidant Activity and Chemical Constituents from Stem Bark of Ficus abutilifolia. Miq (Moraceae)

Abstract

Aims: The present study was conducted to determine the antioxidant activity and chemical components of Ficus abutilifolia. Miq. (Moraceae). Place and Duration of the Study: The study were performed at Department of chemistry, University of Ngaoundere, Cameroon, between July 2017 and September 2018. Methodology: Phytochemical study was carried out on all extracts of stem barks. Besides, the total phenols contents (TPC) using the Folin-Ciocalteu and the antioxidant activities using DPPH and FRAP methods were also evaluated. The isolation of compounds from the EtOAc extract was done using column and thin layer chromatographic techniques on silica gel. The structures of isolated constituents were elucidated using mass spectrometry, 1D and 2D-NMR techniques. Results: Phytochemical screening revealed that all the compounds tested were found to be present in the acetone extract; the hexane extract was the poorest in compounds. Acetone extract, DCM/MeOH (1:1) and MeOH extracts were found to be rich in phenols with TPC respectively (239. 849 ± 0.969), (232.676 ± 0.404) and (109.654 ± 0.724) mg EAG/100g EX. Except the n-hexane extract, all the others exhibit antioxidant activities, acetone extract being the most effective with an inhibitory concentration 50 (IC50) of (0.038 ± 0.002) mg/mL for the DPPH antiradical scavenging activity and (0,021 ± 0,002) mg/mL for FRAP. A new fatty acid named Pentacosyl henicosanoate (2) along with six known compounds Octatriacontane (1), β–sitosterol (3), a mixture of Lupeol acetate (4a), α-amyrin acetate (4b), β-amyrin acetate (4c) and Daucosterol (5) were isolated from the column chromatography of the ethyl acetate extract. Daucosterol (5) exhibited antiradical activity with an IC50 of (13.005 ± 0.005) mg/mL. Only Daucosterol (5) has exhibited antiradical activity with an IC50 of (13.005 ± 0.005) mg/mL among the isolated compounds. Conclusion: This study provides scientific evidence and support for the traditional uses of F. abutilifolia stem barks in the treatment of diseases associated with oxidative stress.