DPPH Radical Scavenging and Xanthine Oxidase Inhibitory Activity of Terminalia macroptera Leaves

Abstract

From a methanol extract of the leaves of the Malian medicinal tree Terminalia macroptera, cis-polyisoprene (1), chebulic acid trimethyl ester (2), methyl gallate (3), shikimic acid (4), corilagin (5), rutin (6), narcissin (7), chebulagic acid (8) and chebulinic acid (9), were isolated. Cis-polyisoprene (1) was the major non-polar constituent. The novel compound 2 showed high radical scavenging activity (IC₅₀ 4.7 μg/mL), but was inactive as xanthine oxidase inhibitor. The major substituent of the crude extract, substance 5, showed a high radical scavenger effect (IC₅₀ 2.7 μg/mL) and weak xanthine oxidase inhibition (IC₅₀ ca 105 μg/mL). The antioxidant and radical scavenging effects of some of the substances identified in this study may to some extent explain the medical use of this tree in West Africa.