Relationship between vasorelaxation of flavonoids and their retention index in RP-HPLC

In the present study the relationship between the vasodilation of flavonoids and their retention index (RI) was investigated. Retention index (RI) values of 18 flavonoids, including flavones, flavonols, flavanones, flavanols and isoflavones were measured by an RP-HPLC method based on alkan-2-ones. Vasorelaxation of the flavonoids was measured by measuring the reduction in tension by flavonoids in rat thoracic aorta precontracted by phenylephrine (PE, 10(-6) mol/L). The results demonstrated that the potency of the vasorelaxation of flavonoids was positive by correlated with RI. The regression equation was Rex 11.68 + 0.11 RI (n = 18, r = 0.915, P < 0.01).