Abstract An H/D exchange process in patuletin (1) and its derivatives in D-donor solvents (eg, CF 3 COOD), which occurs regioselectively at C (8) was observed for the first time during NMR studies. The effect of substituents and temperature on the deuteration of various flavonoids (see Fig. 1) which include apigenin, chrysin, galangin, kaempferol, luteolin, morin, myricetin, patuletin, patulitrin, and quercetin, as well as derivatives of patuletin was ...