Antioxidant activities, total phenolic contents and chemical compositions of extracts from four Cameroonian woods: Padouk (Pterocarpus soyauxii Taubb), tali (Erythrophleum suaveolens), moabi (Baillonella toxisperma), and movingui (Distemonanthus benthamianus)

Abstract

The antioxidant activities, total phenolic contents and chemical compositions of extracts from four Cameroonian woods were investigated. The antioxidant activities were evaluated using the scavenging of 2-2-diphenyl-1-picrylhydrazyl radical (DPPH·) and the oxygen uptake method. The total phenolic content (TPC) was evaluated according to the Folin–Ciocalteu assay in which gallic acid was used as standard. Condensed tannins were evaluated by using the Stiasny method. Chemical compositions of the extracts were evaluated by GC–MS. The results show that toluene/ethanol extracts from tali (Erythrophleum suaveolens) exhibit the highest antioxidant activity with CE50 value of 3.1mg/L followed by movingui (Distemonanthus benthamianus) extracts (CE50 value 3.9mg/L), padouk (Pterocarpus soyauxii Taubb) and moabi (Baillonella toxisperma) (CE50 value of 5.5mg/L and 44mg/L respectively). The TPC and condensed tannins of extracts were in the range of 54–992mg eq. gallic acid/g of extract and 8–60%, respectively. Homopterocarpin and pterocarpin were the major compounds found in the extracts of padouk. Catechin, gallic acid, and pyrogallol were the major compounds identified in tali extracts. Movingui extracts principally contain diterpenes. Gallic acid, squalene and triperpenes were the major compounds of moabi extracts.