title: Norclerodane diterpenoids from rhizomes of Dioscorea bulbifera.
abstract: Three norclerodane diterpenoids, diosbulbins K-M, and one analogous enolglycoside, diosbulbinoside G, together with four norclerodane diterpenoids, diosbulbins B, E, F and G, were isolated from rhizomes of Dioscorea bulbifera. Their structures were established by spectroscopic and chemical methods, including 1H and 13C NMR, NOESY, HSQC, HMBC, and HRMS analyses. The relative configurations of diosbulbins K and L, and diosbulbin F were confirmed by X-ray crystallographic diffraction analysis, and the absolute stereochemistry of diosbulbin K was determined by a modified Mosher's method. The 13C NMR spectroscopic data for diosbulbins E, F and G were also measured for the first time. The compounds did not show significant cytotoxic and anti-bacterial activities.
authors.affiliation: The MOE Key Laboratory for Standardization of Chinese Medicines, Institute of Traditional Chinese Medicine, Shanghai University of Traditional Chinese Medicine, 1200 Cailun Road, Shanghai 201210, China.
authors.forename: Hai
authors.initials: H
authors.lastname: Liu
authors.forename: Gui-Xin
authors.initials: GX
authors.lastname: Chou
authors.forename: Yin-Long
authors.initials: YL
authors.lastname: Guo
authors.forename: Li-Li
authors.initials: LL
authors.lastname: Ji
authors.forename: Jun-Ming
authors.initials: JM
authors.lastname: Wang
authors.forename: Zheng-Tao
authors.initials: ZT
authors.lastname: Wang
mesh_terms: D000935:Antifungal Agents / Q000737:chemistry / Q000302:isolation & purification / Q000494:pharmacology; D018360:Crystallography, X-Ray; D027742:Dioscorea / Q000737:chemistry*; D004224:Diterpenes / Q000737:chemistry / Q000302:isolation & purification* / Q000494:pharmacology; D009682:Magnetic Resonance Spectroscopy; D013058:Mass Spectrometry; D008826:Microbial Sensitivity Tests; D008958:Models, Molecular; D015394:Molecular Structure
chemical_list: D000935:Antifungal Agents; D004224:Diterpenes