title: Direct infusion ESI-IT-MSn alkaloid profile and isolation of tetrahydroharman and other alkaloids from Bocageopsis pleiosperma maas (Annonaceae).
abstract: BACKGROUND
  The Annonaceae family is known as a promising abundant source of secondary metabolites, especially annonaceous acetogenins, terpenoids and isoquinoline-derived alkaloids. Although widely investigated from the phytochemical viewpoint, this family still presents some largely unexplored genera, e.g. the Bocageopsis.
  
  
  OBJECTIVE
  To investigate the alkaloid content of Bocageopsis pleiosperma Maas using direct infusion electrospray ionisation ion trap tandem mass spectrometry (ESI-IT-MS(n)) analysis.
  
  
  METHODS
  Dichloromethane extracts of aerial parts were subjected to acid-base partitioning to yield the alkaloidal fractions. These fractions were analysed by direct infusion into a (+)ESI-IT-MS(n) system. The alkaloidal fraction from the leaves was also obtained on a large scale and subjected to chromatographic separation.
  
  
  RESULTS
  The tentative MS(n) -based identification of alkaloids in leaves, twigs and trunk bark showed that aporphine alkaloids were restricted to the leaves and twigs, tetrahydroprotoberberine alkaloids were only found in the twigs and trunk bark while benzylisoquinoline alkaloids were found in the leaves, twigs and trunk bark. Chromatographic separation of the leaf alkaloidal fraction yielded the aporphine alkaloids nornuciferine, asimilobine and isoboldine, the β-carboline alkaloid tetrahydroharman and some mixtures containing benzylisoquinoline and aporphine alkaloids, all described for the first time in the Bocageopsis genus. Furthermore, tetrahydroharman has not previously been reported in the Magnoliales order.
  
  
  CONCLUSIONS
  Direct infusion ESI-IT-MS(n) analysis of alkaloids allowed fast recognition of alkaloidal classes previously reported in the Annonaceae family, aiding the chromatographic step and allowing a selective isolation of compounds previously not identified in the Bocageopsis genus.
authors.affiliation: Department of Chemistry, Federal University of Amazonas, 69077-000, Manaus, AM, Brazil.
authors.forename: Elzalina R
authors.initials: ER
authors.lastname: Soares
authors.affiliation: Department of Chemistry, Federal University of Amazonas, 69077-000, Manaus, AM, Brazil.
authors.forename: Felipe M A
authors.initials: FM
authors.lastname: da Silva
authors.affiliation: Department of Chemistry, Federal University of Amazonas, 69077-000, Manaus, AM, Brazil.
authors.forename: Richardson A
authors.initials: RA
authors.lastname: de Almeida
authors.affiliation: Department of Chemistry, Federal University of Amazonas, 69077-000, Manaus, AM, Brazil.
authors.forename: Bruna R
authors.initials: BR
authors.lastname: de Lima
authors.affiliation: Department of Chemistry, Federal University of Amazonas, 69077-000, Manaus, AM, Brazil.
authors.forename: Francinaldo A
authors.initials: FA
authors.lastname: da Silva Filho
authors.affiliation: NMR Center, Federal University of Paraná, 81531-990, Curitiba, PR, Brazil.
authors.forename: Andersson
authors.initials: A
authors.lastname: Barison
authors.affiliation: Department of Chemistry, Federal University of Amazonas, 69077-000, Manaus, AM, Brazil.|Institute of Chemistry, University of Campinas, 13083-970, Campinas, SP, Brazil.
authors.forename: Hector H F
authors.initials: HH
authors.lastname: Koolen
authors.affiliation: Department of Chemistry, Federal University of Amazonas, 69077-000, Manaus, AM, Brazil.
authors.forename: Maria Lúcia B
authors.initials: ML
authors.lastname: Pinheiro
authors.affiliation: Department of Chemistry, Federal University of Amazonas, 69077-000, Manaus, AM, Brazil.
authors.forename: Afonso D L
authors.initials: AD
authors.lastname: de Souza
mesh_terms: D000470:Alkaloids / Q000032:analysis* / Q000737:chemistry / Q000302:isolation & purification; D029061:Annonaceae / Q000737:chemistry*; D005591:Chemical Fractionation / Q000379:methods; D006246:Harmaline / Q000031:analogs & derivatives* / Q000032:analysis / Q000737:chemistry / Q000302:isolation & purification; D009682:Magnetic Resonance Spectroscopy / Q000379:methods; D015394:Molecular Structure; D024301:Plant Bark / Q000737:chemistry; D035261:Plant Components, Aerial / Q000737:chemistry; D018515:Plant Leaves / Q000737:chemistry; D015203:Reproducibility of Results; D021241:Spectrometry, Mass, Electrospray Ionization / Q000379:methods*; D053719:Tandem Mass Spectrometry / Q000379:methods*
chemical_list: D000470:Alkaloids; C023426:tetrahydroharmane; D006246:Harmaline
keywords: Alkaloid profiling; Bocageopsis pleiosperma; isoquinoline-derived alkaloids; tetrahydroharman