Abstract: In order to investigate the active substances of Coleus forskohlii (Willd.) Briq., a new labdane diterpenoid, 12-hydroxy-8,13E-labdadien-15-oic acid, together with two 8,13-epoxylabd-14-ene-11-one diterpenoids, 6-acetyl-1-deoxyforskolin and 6-acetyl-1,9-dideoxyforskolin, was isolated on the basis of various chromatographic techniques and spectroscopic methods.(Author for correspondence.Tel: +86(0)25 8539 1289; Fax: +86(0)25 8530 1528; E-mail: lykong@jlonline.com)

Key words: 6-acetyl-1-deoxyforskolin, 6-acetyl-1,9-dideoxyforskolin, Coleus forskohlii, 12-hydroxy-8,13E-labdadien-15-oic acid, labdane diterpenoid.