Production of C-13-labelled anthocyanins by Vitis vinifera cell suspensioncultures

The use of plant cell cultures for producing isotopically (C-13) labelled p henolic substances is reported. Vitis vinifera cells synthesize high levels of anthocyanins when they are cultured in a polyphenol synthesis-inducing medium. Three major anthocyanin monoglucosides found in red wine were ident ified in grape cells: cyanidin-3-O-beta-glucoside, peonidin-3-O-beta-glucos ide, and malvidin-3-O-beta-glucoside. Kinetic study of the intracellular le vel of phenylalanine and its metabolites showed that it is preferable to ad d this precursor to grape cell suspensions after the 5th day of culture, i. e. at the beginning of the exponential growth phase. After adding phenylala nine to the culture medium, its uptake was complete and the accumulation of anthocyanins in grape cells was stimulated. Incorporation of [1-C-13]-phen ylalanine into anthocyanins was measured by means of C-13 satellites in the proton NMR spectrum. The maximal rate of C-13 enrichment anthocyanins obta ined with this technique reached 65%. The production of C-13 labelled pheno lic compounds was undertaken in order to investigate their absorption and m etabolism in humans. (C) 1999 Elsevier Science Ltd. All rights reserved.