Two new diterpenoids from Plectranthus nummularius BRIQ

Abstract

Two new antioxidative diterpenoids, plectranthol A (3)[19-O-(3,4-dihydroxybenzoyl)-11,12-dihydroxy-20(10→5)-abeo-abieta- 1(10),6,8,11,13-tetraene] and plectranthol B (4)[12-O-(3-methyl-2-butenoyl)-19-O-(3, 4-di-hydroxybenzoyl)-11-hydroxyabieta- 8,11,13-triene] along with two known diterpenoids, parvifloron E (1) and F (2) were isolated from the leaves of Plectranthus nummularius BRIQ. Antioxidative activities of the compounds were measured by the α,α-diphenyl-β-picrylhydrazyl (DPPH) method.