title: Alkaloids from the Chinese vine Gnetum montanum.
abstract: During a high-throughput screening campaign of a prefractionated natural product library, fractions from the Chinese vine Gnetum montanum showed in vitro activity against Pseudomonas aeruginosa wild-type strain, PAO1. UV-directed isolation of the organic extract from the vine leaves resulted in the purification of the new natural products N-methyllaudanosolinium trifluoroacetate (1), 3'-hydroxy-N,N-dimethylcoclaurinium trifluoroacetate (2), 1,9,10-trihydroxy-2-methoxy-6-methylaporphinium trifluoroacetate (3), and 6a,7-didehydro-1,9,10-trihydroxy-2-methoxy-6-methylaporphinium trifluoroacetate (4). Compound 4 is described here for the first time, and this is the first report of compounds 1-3 as natural products. Compounds 1-3 were found to racemize over time. Starting from commercially available (+)-boldine, through a series of semisynthetic reactions, a mechanism for the racemization of the isolated compounds is proposed. The known natural products (-)-latifolian A (5) and magnocurarine (6) were also isolated during these studies. The antibacterial activity was explained by the presence of 5, which displayed an IC50 value of 9.8 μM (MIC = 35 μM).
authors: Eskitis Institute, Griffith University, Brisbane, QLD 4111, Australia.
authors: Frédéric
authors: F
authors: Martin
authors: Tanja
authors: T
authors: Grkovic
authors: Melissa L
authors: ML
authors: Sykes
authors: Todd
authors: T
authors: Shelper
authors: Vicky M
authors: VM
authors: Avery
authors: David
authors: D
authors: Camp
authors: Ronald J
authors: RJ
authors: Quinn
authors: Rohan A
authors: RA
authors: Davis
mesh_terms: D000470:Alkaloids / Q000737:chemistry / Q000302:isolation & purification* / Q000494:pharmacology; D000900:Anti-Bacterial Agents / Q000302:isolation & purification; D001060:Aporphines / Q000737:chemistry / Q000302:isolation & purification* / Q000494:pharmacology; D044182:Benzylisoquinolines / Q000737:chemistry / Q000302:isolation & purification* / Q000494:pharmacology; D004365:Drugs, Chinese Herbal / Q000737:chemistry / Q000302:isolation & purification* / Q000494:pharmacology; D035684:Gnetum / Q000737:chemistry*; D008826:Microbial Sensitivity Tests; D015394:Molecular Structure; D018515:Plant Leaves / Q000737:chemistry; D011550:Pseudomonas aeruginosa / Q000187:drug effects; D013211:Staphylococcus aureus / Q000187:drug effects
chemical_list: D000470:Alkaloids; D000900:Anti-Bacterial Agents; D001060:Aporphines; D044182:Benzylisoquinolines; D004365:Drugs, Chinese Herbal