title: Daphcalycine, a novel heptacycle fused ring system alkaloid from Daphniphyllum calycinum.
abstract: A novel Daphniphyllum alkaloid, daphcalycine (1), was isolated together with known daphnicyclidin D (2) from the stem bark of Daphniphyllum calycinum. The highly condensed polycyclic structure, established by spectral analysis, possessed an unusual framework: a central quinuclidine like tricycle produced by fusion of a piperidine, a tetrahydropyran, and an oxazine ring in turn condensed to surrounding three penta-, one hexa-, and one hepta-membered rings. The relative configuration of 11 carbon stereocenters of 1 was elucidated on the basis of NOESY.
authors.affiliation: Laboratoire de Chimie des Substances Naturelles, ESA 8041 CNRS, Muséum National d'Histoire Naturelle, 63 rue Buffon 75005 PARIS, France. jossang@mnhn.fr
authors.forename: Akino
authors.initials: A
authors.lastname: Jossang
authors.forename: Hoda
authors.initials: H
authors.lastname: El Bitar
authors.forename: Van Cuong
authors.initials: VC
authors.lastname: Pham
authors.forename: Thierry
authors.initials: T
authors.lastname: Sévenet
mesh_terms: D000470:Alkaloids / Q000737:chemistry / Q000302:isolation & purification*; D006576:Heterocyclic Compounds, 4 or More Rings / Q000737:chemistry / Q000302:isolation & purification*; D008968:Molecular Conformation; D015394:Molecular Structure; D019906:Nuclear Magnetic Resonance, Biomolecular; D024301:Plant Bark / Q000737:chemistry; D018547:Plant Stems / Q000737:chemistry; D010946:Plants, Medicinal / Q000737:chemistry*; D014744:Vietnam
chemical_list: D000470:Alkaloids; D006576:Heterocyclic Compounds, 4 or More Rings; C474769:daphcalycine