Two new diterpenoids from Plectranthus nummularius Briq.

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-dihydroxybenzoyl)-11-hydroxyabieta-8,11,13-trienel 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 alpha,alpha-diphenyl-beta-picrylhydrazyl (DPPH) method.