Measurement and modeling of radical scavenging by flavonoids

V. Butkovic, S. Kazazic, N. Kezele, L. Klasinc
Rudjer Boškoviæ Institute, Zagreb, Croatia

and Wolf Bors
Institut fur Strahlenbiologie, GSF Forschungszentrum Neuherberg, D-85758 Oberschleissheim, Germany

The relationship between structure and either the antioxidant or the important radical scavenging property of flavonoids is still unclear.The reaction of several mutually related flavonoids: kaempferol, quercetin, myricetin, robinetin, quercetagetin, naringenin, (+)-dihydroquercetin, apigenin, and baicalein with 1,1-diphenyl-2-picrylhydrazyl (DPPH) in methanol was used to determine their antiradical activity expressed as percentage of reacted DPPH after 5 minutes (see:S.Burda and W. Oleszek, J. Agric. Food Chem. 2001, 49, 2774-2779). Using the variable connectivity index introduced by Randiæ (M. Randiæ, Chemometrics Intel. Lab. Syst. 10,1991, 213-227.) the antiradical activity was modeled with three parameters describing the flavonoid structure.