title: Application of pH-zone-refining countercurrent chromatography for the separation of indole alkaloids from Aspidosperma rigidum Rusby.
abstract: Species of Aspidosperma (Apocynaceae) are characterized by the occurrence of indole alkaloids, but few recent reports on Aspidosperma rigidum Rusby chemical constituents were found. The present work shows the application of pH-zone refining countercurrent chromatography on the separation of alkaloids from the barks of A. rigidum. In this study, the dichloromethane extract was fractionated with the solvent system composed of methyl-tert-butyl ether and water with different concentrations of the retainer triethylamine in the organic stationary phase and formic or hydrochloric acids as eluters in the aqueous mobile phase, in order to evaluate the most suitable condition. In each experiment, from circa 200mg of the dichloromethane extract of A. rigidum, three major alkaloids were isolated and identified as 3α-aricine (circa 17mg), isoreserpiline (ca. 22mg) and 3β-reserpiline (ca. 40mg), with relative purity of 79%, 89% and 82% respectively, in a one-step separation of 2h. Two of them - 3α-aricine and isoreserpiline - were isolated and identified for the first time in this species.
authors.affiliation: Universidade Federal do Rio de Janeiro, Faculdade de Farmácia, CCS, Bl. A 2(o) andar, Ilha do Fundão 21941-590, RJ, Brazil; Institute of Food Chemistry, Technische Universität Braunschweig, Schleinitzstrasse 20, 38106 Braunschweig, Germany. Electronic address: mnvieira87@gmail.com.
authors.forename: Mariana N
authors.initials: MN
authors.lastname: Vieira
authors.forename: Suzana G
authors.initials: SG
authors.lastname: Leitão
authors.forename: Paula C C
authors.initials: PC
authors.lastname: Porto
authors.forename: Danilo R
authors.initials: DR
authors.lastname: Oliveira
authors.forename: Shaft Corrêa
authors.initials: SC
authors.lastname: Pinto
authors.forename: Raimundo
authors.initials: R
authors.lastname: Braz-Filho
authors.forename: Gilda G
authors.initials: GG
authors.lastname: Leitão
mesh_terms: D030009:Aspidosperma / Q000737:chemistry*; D002851:Chromatography, High Pressure Liquid; D003377:Countercurrent Distribution / Q000379:methods*; D006863:Hydrogen-Ion Concentration; D026121:Indole Alkaloids / Q000302:isolation & purification*; D008752:Methylene Chloride / Q000737:chemistry
chemical_list: D026121:Indole Alkaloids; D008752:Methylene Chloride
keywords: Aspidosperma; Indole alkaloids; pH-zone-refining countercurrent chromatography