Evaluation on antioxidant activity, antifungal activity and total phenols of 11 selected commercial Malaysian timber species

Abstract

Antioxidant activity [1,1-diphenyl-2-picrylhydrazyl (DPPH) assay], antifungal activity against Gloeophyllum trabeum (brown-rot) and Pycnoporus sanguineus (white-rot), and total phenol content (Folin-Ciocalteu method) of 11 selected commercial Malaysian timbers were investigated. The extracts from Neem bark showed the highest yield, 25.59%. Kelat gelam bark showed the highest antioxidant activity, followed by Kelat jambu air bark. The extracts that showed the four highest antioxidant activities were all taken from bark samples. These extracts also showed high yields of methanol extracts and high total phenol content, suggesting that they have great potential as a source of antioxidant material. The highest total phenol content was found in Neem bark, while the lowest was in Ramin melawis bark. The methanol extracts from the heartwood of Neem showed the highest antifungal activity against G. trabeum. The methanol extracts from the sapwood and the heartwood of Neem, and the heartwood of Kulim showed the highest antifungal activity against P. sanguineus. The antifungal activities of these methanol extracts were higher than those of the positive control, glycyrrhizic acid dipotassium salt. Almost all wood species showed antifungal activity against either brown-or white-rot fungus. However, methanol extracts from the heartwood of Neem showed strong antifungal activity against brown and white-rot fungi, G. trabeum and P. sanguineus, suggesting that they have great potential as a source of fungistats.