title: Novel alkaloids from the roots of Stemona sessilifolia.
abstract: Four new Stemona alkaloids, sessilistemonamines A-C (1-3, resp.) and dihydrostemoninine (4), were isolated from the roots of Stemona sessilifolia. Their structures and relative configurations were elucidated by means of in-depth 1D- and 2D-NMR-spectroscopic as well as mass-spectrometric experiments; and the structure of 4 was solved by X-ray single-crystal diffraction. The stereoisomeric compounds 1-3 share an unprecedented tetracyclic decahydro-1H-furo[2',3':4,5]cyclopenta[1,2-b]pyrrolo[1,2-a]azepine nucleus. Compounds 1 and 2 were found to be moderately active in terms of acetylcholinesterase (AchE) inhibition, with IC50 values of 68.8+/-9.5 and 17.1+/-2.5 microM, resp.
authors: Institute of Materia Medica, Chinese Academy of Medical Sciences & Peking Union Medical College (Key Laboratory of Bioactive Substances and Resources Utilization of Chinese Herbal Medicine, Ministry of Education), Beijing 100050, PR China.
authors: Peng
authors: P
authors: Wang
authors: Ai-Lin
authors: AL
authors: Liu
authors: Zheng
authors: Z
authors: An
authors: Zhi-Hong
authors: ZH
authors: Li
authors: Guan-Hua
authors: GH
authors: Du
authors: Hai-Lin
authors: HL
authors: Qin
mesh_terms: D000470:Alkaloids / Q000737:chemistry / Q000302:isolation & purification*; D002800:Cholinesterase Inhibitors / Q000737:chemistry / Q000302:isolation & purification; D010936:Plant Extracts / Q000737:chemistry / Q000302:isolation & purification; D018517:Plant Roots; D041901:Stemonaceae
chemical_list: D000470:Alkaloids; D002800:Cholinesterase Inhibitors; D010936:Plant Extracts