title: New isosteroidal alkaloids with tracheal relaxant effect from the bulbs of Fritillaria pallidiflora Schrenk.
abstract: Four new isosteroidal alkaloids, yibeinones A-D (1-4), along with four known ones, imperialine-3β-d-glucoside (5), imperialine (6), imperialine β-N-oxide (7), and dongbeinine (8), were isolated from the bulbs of Fritillaria pallidiflora. Their structures were confirmed on the basis of extensive spectroscopic analysis or comparison with the data in the literatures (known compounds). Compounds 2, 3, 4, and 6 showed an apparent concentration-dependant relaxation of isolated tracheal preparation, amongst 3 and 6 exhibited significant effects with pA2 values of 6.19 ± 0.02 and 8.41 ± 0.10, and EC50 values of 0.65 ± 0.02 μmol L(-1) and 4.40 ± 0.90 nmol L(-1), respectively.
authors.affiliation: Key Laboratory of Plants Resources and Chemistry of Arid Zone, Xinjiang Technical Institute of Physics and Chemistry, Chinese Academy of Sciences, Beijing South Road 40-1, Urumqi 830011, Xinjiang, PR China; University of Chinese Academy of Sciences, Beijing 100039, PR China.
authors.forename: Yan
authors.initials: Y
authors.lastname: Li
authors.affiliation: Key Laboratory of Plants Resources and Chemistry of Arid Zone, Xinjiang Technical Institute of Physics and Chemistry, Chinese Academy of Sciences, Beijing South Road 40-1, Urumqi 830011, Xinjiang, PR China; State Key Laboratory Basis of Xinjiang Indigenous Medicinal Plants Resource Utilization, Xinjiang Technical Institute of Physics and Chemistry, Chinese Academy of Sciences, Urumqi 830011, Xinjiang, PR China.
authors.forename: Abulimiti
authors.initials: A
authors.lastname: Yili
authors.affiliation: State Key Laboratory Basis of Xinjiang Indigenous Medicinal Plants Resource Utilization, Xinjiang Technical Institute of Physics and Chemistry, Chinese Academy of Sciences, Urumqi 830011, Xinjiang, PR China.
authors.forename: Jun
authors.initials: J
authors.lastname: Li
authors.affiliation: State Key Laboratory Basis of Xinjiang Indigenous Medicinal Plants Resource Utilization, Xinjiang Technical Institute of Physics and Chemistry, Chinese Academy of Sciences, Urumqi 830011, Xinjiang, PR China; University of Chinese Academy of Sciences, Beijing 100039, PR China.
authors.forename: Aziz
authors.initials: A
authors.lastname: Muhamat
authors.affiliation: Key Laboratory of Plants Resources and Chemistry of Arid Zone, Xinjiang Technical Institute of Physics and Chemistry, Chinese Academy of Sciences, Beijing South Road 40-1, Urumqi 830011, Xinjiang, PR China; State Key Laboratory Basis of Xinjiang Indigenous Medicinal Plants Resource Utilization, Xinjiang Technical Institute of Physics and Chemistry, Chinese Academy of Sciences, Urumqi 830011, Xinjiang, PR China. Electronic address: haji@ms.xjb.ac.cn.
authors.forename: Haji Akber
authors.initials: HA
authors.lastname: Aisa
mesh_terms: D000470:Alkaloids / Q000737:chemistry / Q000302:isolation & purification / Q000494:pharmacology*; D000818:Animals; D004305:Dose-Response Relationship, Drug; D004365:Drugs, Chinese Herbal / Q000737:chemistry / Q000302:isolation & purification / Q000494:pharmacology*; D031410:Fritillaria / Q000737:chemistry*; D008968:Molecular Conformation; D009126:Muscle Relaxation / Q000187:drug effects / Q000502:physiology; D018517:Plant Roots / Q000737:chemistry*; D011189:Potassium Chloride / Q000494:pharmacology; D051381:Rats; D013329:Structure-Activity Relationship; D014132:Trachea / Q000187:drug effects* / Q000502:physiology
chemical_list: D000470:Alkaloids; D004365:Drugs, Chinese Herbal; D011189:Potassium Chloride
keywords: Fritillaria pallidiflora; Isosteroidal alkaloid; Tracheal relaxant effect; Yibeinones A–D