TY  - BOOK
AU  - Van Acker,S.A.B.E.
AU  - Van Den Berg,D.J.
AU  - Tromp,M.J.L.
AU  - Griffioen,D.H.
AU  - Van Bennekom,W.P.
AU  - Van Der Vijgh,W.J.F.
AU  - Bast,A.
TI  - Structural aspects of antioxidant activity of flavonoids
KW  - FREE RADICALS
KW  - ANTIOXIDANT
KW  - FLAVONOID
KW  - OXIDATION POTENTIAL
KW  - LIPID PEROXIDATION
N2  - Flavonoids, a group of naturally occurring antioxidants and iron chelators, might be used as cardioprotective agents in doxorubicin-induced cardiotoxicity, which is believed to be caused by the formation of oxygen free radicals. To investigate the underlying molecular mechanism, we tested a large group of flavonoids from all major structural subclasses on their ability to inhibit doxorubicin (enzymatically)-induced and e2+/ascorbate (nonenzymatically)-induced microsomal lipid peroxidation (LPO)and to chelate Fe 2÷ . In addition, we measured half peak oxidation potentials (Ep/2). LPO inhibition data gave a good qualitative correlation with the oxidation potentials. Most flavonoids tested chelated Fe 2÷, but there were large differences in the chelating capacity. For good scavenging activity, a catechol moiety on ring B is required. The 3-OH moiety can function as a chelation site and can also be oxidized. The 3-OH group in combination with a C2 C3 double bond, increases the cavenging activity. Fe 2÷ chelation only plays a role in the LPO inhibition by less active scavengers. Chelation can then raise the activity to the level of the most active scavengers, possibly by site-specific scavenging. It can be concluded that Ep/2 values and iron chelating activity can almost completely describe the LPO inhibiting behaviour of the flavonoids
UR  - https://drive.google.com/file/d/1_tdzNoeHTxkRpp7MTVBQwa1LvhvEZTLN/view?usp=drivesdk
ER  -