Antioxidant Activity of Abietane-Type Diterpenes from Heartwood of Taiwania cryptomerioides Hayata

Abstract

Summary Nine abietane-type diterpenes were isolated from the heartwood of Taiwania cryptomerioides and their structures identified by spectral analyses. Among these nine compounds, six diterpenes were isolated for the first time from T. cryptomerioides, including 6,7-dehydroferruginol, 6α-hydroxysugiol, 5,6-dehydro-6-hydroxysugiol, 11-hydroxyferruginol, secoabietane dialdehyde and isohinokiol. We suggest that abietane-type diterpenes are the dominant diterpenes in the heartwood of T. cryptomerioides. A possible biosynthesis pathway is proposed. In addition, a 1,1-diphenyl-2-picrylhydrazyl (DPPH) assay was performed to evaluate the antioxidant activity of these diterpenes. This study demonstrates that ferruginol exhibits the strongest antioxidant activity among the diterpenes isolated from T. cryptomerioides heartwood.