title: Steroids, alkaloids, and coumarins from Gelsemium sempervirens.
abstract: The 95 % ethanol extract of Gelsemium sempervirens showed inhibitory activity against human DNA topoisomerase I (Topo I). Phytochemical investigations of this active extract resulted in the isolation and identification of three new steroids ( 1 - 3), together with eight known compounds 12 beta-hydroxy-5 alpha-pregn-16-ene-3,20-dione ( 4), gelsemine ( 5), sempervirine ( 6), scopoletin ( 7), 7- O- beta- D-glucopyranosylscopoletin ( 8), 7- O- beta- D-apiofuranosyl-(1-->6)- beta- D-glucopyranosylscopoletin ( 9), uvaol ( 10), and 2-(4-hydroxyphenyl)ethyl heptadecanoate ( 11). The structures of the new steroids were determined by extensive NMR and HR-ESI-MS analyses as 21-hydroxy-5 alpha-pregn-16-ene-3,20-dione ( 1), 3-oxoandrosta-16-ene-17-carboxylic acid ( 2), and 3-oxoandrosta-4,16-diene-17-carboxylic acid ( 3). This study suggests that sempervirine ( 6) intercalates to DNA and also inhibits Topo I through modulating the enzyme activity with an IC (50) of 54.5 +/- 15.9 muM.
authors.affiliation: National Center for Pharmaceutical Crops, Arthur Temple College of Forestry and Agriculture, Stephen F. Austin State University, Nacogdoches, Texas, USA.
authors.forename: Zhizhen
authors.initials: Z
authors.lastname: Zhang
authors.forename: Ping
authors.initials: P
authors.lastname: Wang
authors.forename: Wei
authors.initials: W
authors.lastname: Yuan
authors.forename: Shiyou
authors.initials: S
authors.lastname: Li
mesh_terms: D000470:Alkaloids / Q000737:chemistry / Q000302:isolation & purification*; D000736:Androstenes / Q000737:chemistry / Q000302:isolation & purification; D003374:Coumarins / Q000737:chemistry / Q000302:isolation & purification*; D031450:Gelsemium / Q000737:chemistry*; D006801:Humans; D009682:Magnetic Resonance Spectroscopy; D015394:Molecular Structure; D035261:Plant Components, Aerial; D011282:Pregnenediones / Q000737:chemistry / Q000302:isolation & purification; D046948:Secologanin Tryptamine Alkaloids / Q000737:chemistry / Q000302:isolation & purification / Q000494:pharmacology*; D013256:Steroids / Q000737:chemistry / Q000302:isolation & purification*; D059004:Topoisomerase I Inhibitors
chemical_list: D000470:Alkaloids; D000736:Androstenes; D003374:Coumarins; D011282:Pregnenediones; D046948:Secologanin Tryptamine Alkaloids; D013256:Steroids; D059004:Topoisomerase I Inhibitors; C009234:sempervirine