title: A new tropane alkaloid from the leaves of Erythroxylum subsessile isolated by pH-zone-refining counter-current chromatography.
abstract: Tropane alkaloids are bioactive metabolites with great importance in the pharmaceutical industry and the most important class of natural products found in the Erythroxylum genus. However, these compounds are usually separated by traditional chromatographic techniques, in which the sample is progressively purified in multiple chromatographic steps, resulting in a time- and solvent-consuming procedure. In this work we present the isolation of a novel alkaloid, 6β,7β-dibenzoyloxytropan-3α-ol, together with the two known 3α-benzoyloxynortropan-6β-ol and 3α,6β-dibenzoyloxytropane alkaloids, directly from the crude alkaloid fraction from the leaves of Erythroxylum subsessile, by using a single run pH-zone-refining counter-current chromatography method. The ethyl acetate/water (1:1, v/v) biphasic solvent system with triethylamine and HCl as retention and eluter agents, respectively, was used to isolate tropane alkaloids for the first time. The structures of the isolated alkaloids were elucidated by spectroscopic methods.
authors.affiliation: Instituto de Pesquisas de Produtos Naturais, Universidade Federal do Rio de Janeiro, Rio de Janeiro, RJ, Brazil.|Curso de Farmácia, Universidade Federal do Amapá, Macapá, AP, Brazil.
authors.forename: Rodrigo Alves Soares
authors.initials: RA
authors.lastname: Cruz
authors.affiliation: Faculdade de Farmácia, Universidade Federal Fluminense, Niterói, RJ, Brazil.
authors.forename: Henrique
authors.initials: H
authors.lastname: Almeida
authors.affiliation: Curso de Farmácia, Universidade Federal do Amapá, Macapá, AP, Brazil.
authors.forename: Caio Pinho
authors.initials: CP
authors.lastname: Fernandes
authors.affiliation: Departamento de Química, Centro de Investigación y de Estudios Avanzados del Instituto Politécnico Nacional, Mexico, D. F., Mexico.
authors.forename: Pedro
authors.initials: P
authors.lastname: Joseph-Nathan
authors.affiliation: Faculdade de Farmácia, Universidade Federal Fluminense, Niterói, RJ, Brazil.
authors.forename: Leandro
authors.initials: L
authors.lastname: Rocha
authors.affiliation: Instituto de Pesquisas de Produtos Naturais, Universidade Federal do Rio de Janeiro, Rio de Janeiro, RJ, Brazil.
authors.forename: Gilda Guimarães
authors.initials: GG
authors.lastname: Leitão
mesh_terms: D003377:Countercurrent Distribution / Q000379:methods*; D030921:Erythroxylaceae / Q000737:chemistry*; D006863:Hydrogen-Ion Concentration; D015394:Molecular Structure; D018515:Plant Leaves / Q000737:chemistry*; D014326:Tropanes / Q000737:chemistry / Q000302:isolation & purification*
chemical_list: D014326:Tropanes
keywords: Counter-current chromatography; Erythroxylum; Tropane alkaloids