ABSTRACT: Eight new diterpenes, 6α,7β-dihydroxyferruginol (1), 6α,7α-dihydroxyferruginol (2), 6α-hydroxyhinokiol (3), 4α-hydroxy-7-oxo-18-norabieta-8,11,13-trien-4α-ol (4a), 15,16-dehydrosugiol (5), 7-methoxy-6,7-secoabieta-8,11,13-triene-6,12-diol (6), 7α-acetoxyabieta-8,12-diene-11,14-dione (7), 7α-butyloxyethyloxyabieta-8,12-diene-11,14-dione (8), along with four known compounds, 6,7-dehydroferruginol (9), 12-hydroxy-6,7-secoabieta-8,11,13-triene-6,7-dial (10), 7α-11-dihydroxy-12-methoxy-8,11,13-abietatriene (11), and 11,14-dihydroxy-8,11,13-abietatrien-7-one (12) were successfully isolated from the bark of Calocedrus macrolepis var. formosana. The structures of all isolates were elucidated by physical data (appearance, UV, IR, optical rotation) and spectroscopic data (1D, 2D NMR, and HREIMS). Co
