title: Phytochemical and larvicidal studies on Stemona curtisii: structure of a new pyrido[1,2-a]azepine Stemona alkaloid.
abstract: A new pentacyclic Stemona alkaloid, stemocurtisinol (3), with a pyrido[1,2-a]azepine A,B-ring system, and the known pyrrolo[1,2-a]azepine alkaloid oxyprotostemonine (4) have been isolated from a root extract of S. curtisii. The structure and relative stereochemistry of stemocurtisinol was determined by spectral data interpretation and X-ray crystallography. This compound is a diastereoisomer of oxystemokerrin and has the opposite configuration at C-4 and C-19. The individual alkaloid components showed significant larvicidal activity (IC(50) 4-39 ppm) on mosquito larvae (Anopheles minimus HO).
authors.affiliation: Division of Environmental Sciences, Chiang Mai University, Chiang Mai 50202, Thailand.
authors.forename: Pitchaya
authors.initials: P
authors.lastname: Mungkornasawakul
authors.forename: Stephen G
authors.initials: SG
authors.lastname: Pyne
authors.forename: Araya
authors.initials: A
authors.lastname: Jatisatienr
authors.forename: Damrat
authors.initials: D
authors.lastname: Supyen
authors.forename: Chaiwat
authors.initials: C
authors.lastname: Jatisatienr
authors.forename: Wilford
authors.initials: W
authors.lastname: Lie
authors.forename: Alison T
authors.initials: AT
authors.lastname: Ung
authors.forename: Brian W
authors.initials: BW
authors.lastname: Skelton
authors.forename: Allan H
authors.initials: AH
authors.lastname: White
mesh_terms: D000470:Alkaloids / Q000737:chemistry / Q000302:isolation & purification* / Q000494:pharmacology; D000818:Animals; D000852:Anopheles / Q000187:drug effects*; D001381:Azepines / Q000737:chemistry / Q000302:isolation & purification* / Q000494:pharmacology; D018360:Crystallography, X-Ray; D005663:Furans / Q000737:chemistry / Q000302:isolation & purification* / Q000494:pharmacology; D020128:Inhibitory Concentration 50; D007814:Larva / Q000187:drug effects*; D015394:Molecular Structure; D041901:Stemonaceae / Q000737:chemistry*; D013785:Thailand
chemical_list: D000470:Alkaloids; D001381:Azepines; D005663:Furans; C485493:oxyprotostemonine; C485491:stemocurtisinol