The absolute stereostructure of a novel skeletal diterpene, standishinal (1), from the bark of Thuja standishii was confirmed by X-ray crystallographic analyses of 1 and its p-bromobenzoate derivative. Aromatase inhibitory activities of standishinal, eight known diterpenes, totarol,
Three new labdane-type diterpenoids, labda-8(17),13-dien-15,12R-olid-19-oic acid (1), 12S-hydroxylabda-8(17),13(16),14-trien-19-oic acid (2) and 13-ethoxylabda-8(17),11,14-trien-19-oic acid (3), along with known diterpenoids, trans-communic acid (4), totarol (5), 12-methoxyabieta-8,11,13-trien-11-ol