Synthesis and antioxidant activities of flavonoids derivatives, troxerutin and 3’, 4’, 7-triacetoxyethoxyquercetin

Syntheses of two very important derivatives of quercetin, troxerutin and 3’, 4’, 7-triacetoxyethoxy-quercetin were described. The latter was synthesized by highly selective esterification reaction in first time. The compounds were characterized by NMR, IR and Mass spectroscopy. Additionally, the antioxidant activities of the compounds were tested by means of improved pyrogallol autoxidation method. This was the first in using this method to test the antioxidant activities of these two compounds in vitro. The optimum system of pyorgallol autoxidation spectrophotometry was investigated and established according to the reaction rules. The assay indicated that these compounds showed noticeable antioxidant activities, and compound 2 was much more effective as a free radical scavenger than the compound 1 vitamin C was used as a reference material.

Graphical abstractThe compound 2 was synthesized for the first time by highly selective esterification reaction and fully characterized. The by-products of the reaction were complex, which brought out many considerable difficulties in separation and purification of the target product. Our work was the first in using the improved pyrogallol autoxidation method to test the antioxidant activities of these two flavonoids compounds in vitro and discovered that the compound 2 was much more effective as a free radical scavenger than the compound 1.Figure optionsDownload full-size imageDownload as PowerPoint slide