title: Configuration of the vitamin E analogue garcinoic acid extracted from Garcinia Kola seeds.
abstract: Vitamin E derivatives bearing a carboxylic group have recently gained great attention because of their antitumoral properties. Garcinoic acid (trans-13'-carboxy-delta-tocotrienol) is a vitamin E analog extracted from Garcinia Kola seeds in which the carboxylic group is at the end of the aliphatic side chain and reported to be a racemate based on the optical rotation measurements. However, CD determination of a sample of the acid analyzed by us gave a positive peak at 208 nm, indicating that it is not a racemate. To assess the enantiomeric composition of garcinoic acid, it was thus transformed to alpha-tocopherol and analyzed by chiral HPLC on column OD-H. On the basis of the elution order of alpha-tocopherol stereoisomers, the garcinoic acid sample resulted to be enantiopure with R configuration at carbon 2 of the chroman ring. Moreover, in a preliminary test, the acid and some of its derivatives showed a marked antiproliferative effect on glioma C6 cancer cells.
authors.affiliation: Dipartimento di Chimica e Chimica Industriale, Università di Pisa, Pisa 56126, Italy.
authors.forename: Francesco
authors.initials: F
authors.lastname: Mazzini
authors.forename: Michele
authors.initials: M
authors.lastname: Betti
authors.forename: Thomas
authors.initials: T
authors.lastname: Netscher
authors.forename: Francesco
authors.initials: F
authors.lastname: Galli
authors.forename: Piero
authors.initials: P
authors.lastname: Salvadori
mesh_terms: D016588:Anticarcinogenic Agents / Q000494:pharmacology*; D000975:Antioxidants / Q000737:chemistry / Q000494:pharmacology*; D017209:Apoptosis / Q000187:drug effects; D001578:Benzopyrans / Q000737:chemistry / Q000494:pharmacology*; D045744:Cell Line, Tumor; D049109:Cell Proliferation / Q000187:drug effects; D002851:Chromatography, High Pressure Liquid; D004354:Drug Screening Assays, Antitumor; D029763:Garcinia kola / Q000737:chemistry*; D006801:Humans; D015394:Molecular Structure; D010936:Plant Extracts / Q000494:pharmacology; D012639:Seeds / Q000737:chemistry; D013237:Stereoisomerism; D024505:Tocopherols / Q000737:chemistry* / Q000494:pharmacology; D014810:Vitamin E / Q000031:analogs & derivatives / Q000737:chemistry; D024502:alpha-Tocopherol / Q000737:chemistry / Q000494:pharmacology
chemical_list: D016588:Anticarcinogenic Agents; D000975:Antioxidants; D001578:Benzopyrans; D010936:Plant Extracts; C473370:garcinoic acid; D014810:Vitamin E; C082097:tocotrienol, delta; D024502:alpha-Tocopherol; D024505:Tocopherols