title: Eight new clerodane diterpenoids from the bark of Ptychopetalum olacoides.
abstract: Eight new clerodane type diterpenoids, named 7-oxo-kolavelool (1), 7alpha-hydroxykolavelool (2), 6alpha,7alpha-dihydroxykolavenol (3), 12-oxo-hardwickiic acid (4), ptycholide I (5), ptycholide II (6), ptycholide III (7), and ptycholide IV (8) were isolated from the MeOH extract of the bark of a Brazilian medicinal plant, Ptychopetalum olacoides. The structures of 1-8 were elucidated by analyzing spectroscopic data and by comparing their NMR data with those of the previously reported compounds kolavelool (la), kolavenol (3a), hardwickiic acid (4a), and ptychonolide (5a). Compounds 5 and 6 existed as a 1:1 mixture of inseparable epimers at C-15.
authors.affiliation: Faculty of Pharmaceutical Sciences, Tokushima Bunri University, Tokushima 770-8514, Japan.
authors.forename: Wanxia
authors.initials: W
authors.lastname: Tang
authors.forename: Kenichi
authors.initials: K
authors.lastname: Harada
authors.forename: Miwa
authors.initials: M
authors.lastname: Kubo
authors.forename: Hideaki
authors.initials: H
authors.lastname: Hioki
authors.forename: Yoshiyasu
authors.initials: Y
authors.lastname: Fukuyama
mesh_terms: D002942:Circular Dichroism; D004224:Diterpenes / Q000737:chemistry*; D045785:Diterpenes, Clerodane / Q000737:chemistry*; D009682:Magnetic Resonance Spectroscopy; D008958:Models, Molecular; D008968:Molecular Conformation; D031656:Olacaceae / Q000737:chemistry*; D024301:Plant Bark / Q000737:chemistry; D021241:Spectrometry, Mass, Electrospray Ionization; D013055:Spectrophotometry, Infrared; D013056:Spectrophotometry, Ultraviolet
chemical_list: D004224:Diterpenes; D045785:Diterpenes, Clerodane