title: Leonuketal, a Spiroketal Diterpenoid from Leonurus japonicus.
abstract: An architecturally complex spiroketal diterpenoid, leonuketal (1), was isolated from the aerial parts of the plant Leonurus japonicus. This compound possessed an unprecedented tetracyclic skeleton that comprised a bridged spiroketal moiety fused with a ketal-γ-lactone unit. The structure and absolute configuration were determined by spectroscopic analyses, a modified Mosher's method, and ECD (electronic circular dichroism) calculations. Leonuketal (1) showed significant vasorelaxant activity against KCl-induced contraction of rat aorta, with the EC50 value of 2.32 μM.
authors.forename: Liang
authors.initials: L
authors.lastname: Xiong
authors.forename: Qin-Mei
authors.initials: QM
authors.lastname: Zhou
authors.affiliation: Department of Chemistry, University of Pennsylvania , 231 South 34 Street, Philadelphia, Pennsylvania 19104-6323, United States.
authors.forename: Yike
authors.initials: Y
authors.lastname: Zou
authors.affiliation: Institute of Medicinal Biotechnology, Chinese Academy of Medical Sciences and Peking Union Medical College , Beijing 100050, China.
authors.forename: Ming-Hua
authors.initials: MH
authors.lastname: Chen
authors.forename: Li
authors.initials: L
authors.lastname: Guo
authors.forename: Guan-Ying
authors.initials: GY
authors.lastname: Hu
authors.affiliation: Chengdu No. 1 Pharmaceutical Co. Ltd., Chengdu 610031, China.
authors.forename: Zhao-Hua
authors.initials: ZH
authors.lastname: Liu
authors.forename: Cheng
authors.initials: C
authors.lastname: Peng
mesh_terms: D000818:Animals; D001017:Aortic Coarctation / Q000139:chemically induced; D004224:Diterpenes / Q000737:chemistry / Q000302:isolation & purification* / Q000494:pharmacology; D005663:Furans / Q000737:chemistry / Q000302:isolation & purification* / Q000494:pharmacology; D031332:Leonurus / Q000737:chemistry*; D015394:Molecular Structure; D019906:Nuclear Magnetic Resonance, Biomolecular; D035261:Plant Components, Aerial / Q000737:chemistry; D011189:Potassium Chloride / Q000494:pharmacology; D051381:Rats; D013141:Spiro Compounds / Q000737:chemistry / Q000302:isolation & purification* / Q000494:pharmacology
chemical_list: D004224:Diterpenes; D005663:Furans; D013141:Spiro Compounds; C000607092:leonuketal; C520774:spiroketal; D011189:Potassium Chloride