Synthesis Of Soluable Quercetin Derivatives

The methods for preparing quercetin ethers, carboxylic acids, esters,amines, amino acids, glycosides derivatives and metal complexes as well as the current status of study on the biological activities of those derivatives are briefed. However, the poor water solubility and low bioavailability of quercetin limit its clinical application. Therefore, domestic and foreign scholars have made efforts to modify the structure of quercetin and developed a series of novel lead compounds of quercetin, which, hopefully, is to provide references for the design and synthesis of novel quercetin derivatives.12Quercetin derivatives were successfully synthesized, including8new compounds. Their structures were fully characterized by IR^’H-NMR and13C-NMR. These compounds successfully improved the solubility of quercetin.Two quercetin esters derivatives (1and2) were successfully synthesized through sulfonation started from quercetin.The optimum conditions is quercetin with concentrated sulfuric acid in a molar ratio of1:8, the reaction time is3h and the reaction temperature is10℃. The water solubility of the sulfonation product is0.1g/100mL at100℃. Their structures were fully characterized by IR.Two unreported soluable derivatives (11and12) were successfully synthesized to use quercetin as raw material. Both molar atio is11:8, in yield of36.8%. The water solubility of the product is1.5g/100mL at25℃and greatly improved the water solubility of quercetin. Their structures were fully characterized by1H-NMR and13C-NMR.