STUDIES ON MUTAROTATION AND ANOMERIC CONVERSION OF DIHYDROQINGHAOSU

Polarimetry and HPLC were used to study the solution of dihydroqinghaosu in polar solvents such as methanol and ethanol. The mutarotation and conversion of anomers of dihydroqinghaosu were observed and a few kinetic parameters were measured. It was found that the equilibrium constant and the initial forward rate constant of anomeric conversion of dihydroqinghasu (βtoα) depended upon the solvents, temperature and other factors. Hydrochloric acid can be used as a eatalyst for the conversion reaction. A mechanism of the mutarotation and anomeric conversion of dihvdroqinghaosu a kind of hemiacetal was peoposed.