Occurrence in Kava Roots of Kava Lactone-Yielding Precursor(s)

This investigation has shown that the highly biologically active kava lactones, specifically those of desmethoxyyangonin, yangonin and kavain, exist in “locked-up” reserve forms. These important lactones can be regenerated from the totally delactoned polar residues when subjected to reflux at various pHs. The percentage of desmethoxyyangonin, yangonin and kavain regenerated from the same quantity of delactoned residue differed with the pH of the solution. Furthermore, treatment of the delactoned residue with β-D-glucosidase enzyme regenerated desmethoxyyangonin, yangonin and kavain in a pattern similar to that obtained under reflux at pH 5 and 8. These observations, when taken together with the outcome of the control experiment, suggest the presence of sugar bound kava lactone precursors in the delactoned residue.