title: Isolation of flavonoids and triterpenoids from the fruits of Alphitonia neocaledonica and evaluation of their anti-oxidant, anti-tyrosinase and cytotoxic activities.
abstract: BACKGROUND
  Alphitonia neocaledonica (Rhamnaceae) is an endemic tree of New Caledonia. Although three flavonoids have been identified in the leaves, the secondary metabolite profile of the fruits has never been investigated.
  
  
  OBJECTIVE
  Phytochemical investigation of A. neocaledonica fruits and evaluation of their anti-oxidant, anti-tyrosinase and cytotoxic activities.
  
  
  METHODS
  A hydromethanolic extract was fractionated by liquid-liquid extraction to obtain ethyl acetate and n-butanolic fractions. The ethyl-acetate-soluble part was purified by silica-gel column chromatography and high-performance liquid chromatography (HPLC). The n-butanol-soluble part was fractionated by centrifugal partition extraction (CPE) and the collected fractions were further purified by centrifugal partition chromatography (CPC) and HPLC. The chemical structures of the purified compounds were identified by nuclear magnetic resonance and mass spectrometry.
  
  
  RESULTS
  Three triterpenoids and one flavonoid were isolated from the ethyl-acetate-soluble part. Fractions enriched in triterpenoids, flavonoids and catechin derivatives were obtained from the n-butanol-soluble part. Gallocatechin and flavonoids were obtained as pure compounds by further CPC and HPLC purification. The n-butanolic-soluble part showed anti-oxidant and anti-tyrosinase activities due to the presence of tannins and gallocatechin. The triterpenoid alphitolic acid showed a moderate cytotoxic activity against KB cell line (median inhibition concentration = 8.5 μM).
  
  
  CONCLUSIONS
  Nine known compounds including three triterpenes, five flavonoids and (+) gallocatechin, as well as a new 3-O-(6-E-feruloyl)-β-D-glucopyranosyl-(1 → 2)-[β-D-xylopyranosyl-(1 → 2)-]α-L-rhamnopyranosyl-quercetin, were isolated from A. neocaledonia fruits. The hydromethanolic extract possesses a potential cytotoxic activity due to the presence of triterpenes, and it can also be valuable as a cosmetic ingredient for its anti-oxidant and anti-tyrosinase activities.
authors.affiliation: UMR CNRS 7312, Université de Reims Champagne-Ardenne, Bât. 18, Moulin de la Housse, BP 1039, 51687, Reims, Cedex 2, France.
authors.forename: Dima
authors.initials: D
authors.lastname: Muhammad
authors.forename: Jane
authors.initials: J
authors.lastname: Hubert
authors.forename: Nathalie
authors.initials: N
authors.lastname: Lalun
authors.forename: Jean-Hugues
authors.initials: JH
authors.lastname: Renault
authors.forename: Hélène
authors.initials: H
authors.lastname: Bobichon
authors.forename: Mohammed
authors.initials: M
authors.lastname: Nour
authors.forename: Laurence
authors.initials: L
authors.lastname: Voutquenne-Nazabadioko
mesh_terms: D000975:Antioxidants / Q000737:chemistry / Q000302:isolation & purification / Q000494:pharmacology; D045744:Cell Line, Tumor; D002470:Cell Survival / Q000187:drug effects; D002851:Chromatography, High Pressure Liquid; D005419:Flavonoids / Q000737:chemistry / Q000302:isolation & purification* / Q000494:pharmacology; D005638:Fruit / Q000737:chemistry*; D006801:Humans; D059625:Liquid-Liquid Extraction; D014442:Monophenol Monooxygenase / Q000037:antagonists & inhibitors; D009510:New Caledonia; D010936:Plant Extracts / Q000737:chemistry / Q000302:isolation & purification* / Q000494:pharmacology; D027823:Rhamnaceae / Q000737:chemistry*; D014315:Triterpenes / Q000737:chemistry / Q000302:isolation & purification* / Q000494:pharmacology
chemical_list: D000975:Antioxidants; D005419:Flavonoids; D010936:Plant Extracts; D014315:Triterpenes; D014442:Monophenol Monooxygenase
keywords: Alphitonia neocaledonica; Centrifugal partition chromatography; Centrifugal partition extraction; flavonoids; fruits; three-phase solvent system; triterpenoids