STRUCTURE-ACTIVITY RELATIONSHIP IN THE ABILITY OF FLAVONOLS TO INHIBIT CHEMILUMINESCENCE

Fourteen flavonoids were evaluated for their ability to inhibit chemil uminescence, either of neutrophils that had been briefly exposed to bo th luminol and phorbol-myristate acetate or to an enzymatic system wit h H2O2, luminol and horseradish peroxidase. Using chemiluminescence as the quantitative parameter, it can be concluded that the hydroxyl gro up in position 3 of the flavonols is vital for their inhibitory effect , and that two hydroxyl groups on the phenyl ring are optimal for such an effect. It was also noted that the C2-C3 double bond is essential for the flavonols' antioxidative effect. It is suggested that the abil ity of flavonols to suppress chemiluminescence is reciprocally correla ted with their lipophilicity.