FLAVONOIDS FROM THE ROOTS OF 2 RHYNCHOSIA SPECIES USED IN THE PREPARATION OF A ZAMBIAN BEVERAGE

High concentrations of flavonoids were found in the roots of Rhynchosi a insignis and R heterophylla used for the preparation of the popular Zambian munkoyo beverage. The major flavonoids were isolated and ident ified by means of fast atom bombardment mass spectroscopy and co-chrom atography with authentic standards as vicenin-2, schaftoside, isoschaf toside and an isovitexin derivative (in both species) and, additionall y, vitexin, isovitexin and a violanthin-type compound in R heterophyll a. As these compounds are yellow to orange-yellow in the concentration s found in the roots, they are likely to be responsible for the yellow coloration of the beverage before fermentation.