title: 7,7-Dimethylaporphine alkaloids from the stem of Guatteriopsis friesiana.
abstract: Phytochemical investigation of a methanolic extract of the stem of Guatteriopsis friesiana afforded two new 7,7-dimethylaporphine alkaloids, 6,6a-dihydrodemethoxyguadiscine (1) and guatteriopsiscine (3), together with demethoxyguadiscine (2), liriodenine (4), corypalmine (5), and coreximine (6). Their structures were elucidated on the basis of spectroscopic methods (UV, IR, EIMS, HRESIMS, 1D/2D NMR). The absolute configurations of 1 and 3 were determined from the circular dichroism curves. The presence of 7,7-dimethylaporphine alkaloids in this species is important for the chemotaxonomy of Guatteriopsis. Antimicrobial activity of compounds 1-5 was investigated, and 4 showed activity against Rhodococcus equi, with a MIC value of 10 microg x mL(-1).
authors.affiliation: Departamento de Quimica, Universidade Federal do Parana, Centro Politecnico, P.O. Box 19081, 81531-990 Curitiba, PR, Brazil.
authors.forename: Emmanoel Vilaça
authors.initials: EV
authors.lastname: Costa
authors.forename: Francisco A
authors.initials: FA
authors.lastname: Marques
authors.forename: Maria Lúcia B
authors.initials: ML
authors.lastname: Pinheiro
authors.forename: Nelissa P
authors.initials: NP
authors.lastname: Vaz
authors.forename: Marta Cristina T
authors.initials: MC
authors.lastname: Duarte
authors.forename: Camila
authors.initials: C
authors.lastname: Delarmelina
authors.forename: Raquel M
authors.initials: RM
authors.lastname: Braga
authors.forename: Beatriz Helena L N Sales
authors.initials: BH
authors.lastname: Maia
mesh_terms: D000470:Alkaloids / Q000737:chemistry / Q000302:isolation & purification* / Q000494:pharmacology; D029061:Annonaceae / Q000737:chemistry* / Q000145:classification; D000900:Anti-Bacterial Agents / Q000737:chemistry / Q000302:isolation & purification / Q000494:pharmacology; D001060:Aporphines / Q000737:chemistry / Q000302:isolation & purification* / Q000494:pharmacology; D001938:Brazil; D008826:Microbial Sensitivity Tests; D015394:Molecular Structure; D019906:Nuclear Magnetic Resonance, Biomolecular; D018547:Plant Stems / Q000737:chemistry; D016929:Rhodococcus equi / Q000187:drug effects*
chemical_list: D000470:Alkaloids; D000900:Anti-Bacterial Agents; D001060:Aporphines; C026980:liriodenine