4-methylcoumarins as antioxidants: scavenging of peroxyl radicals and inhibition of human low-density lipoprotein oxidation.
The antioxidant activity of eight synthetic 4-methylcoumarins was systematically studied. The antioxidant capacity was measured using: (i) a competition kinetic test, to measure the relative capacity to quench peroxyl radical; (ii) the in vitro oxidative modification of human low-density lipoprotein, initiated by AAPH or catalyzed by copper. In both models, the ortho-OH substitutes were found to be better antioxidant than the meta one. The most efficient antioxidant was the 7,8-dihydroxy-4-methylcoumarin and the corresponding diacetoxy-substituted was unexpectedly a good antioxidant. Finally, the presence of an ethoxycarbonylethyl substituent at the C-3 position increased the antioxidant capacity of both 7,8-dihydroxy-4-methylcoumarin and 7,8-diacetoxy-4-methylcoumarin.
Natella
Fausta
F
National Research Institute on Food and Nutrition, INRAN, Via Ardeatina 546, 00178 Rome, Italy. natella@inran.it
Lorrain
Bénédicte
B
Prasad
Ashok K
AK
Parmar
Virinder S
VS
Saso
Luciano
L
Scaccini
Cristina
C
D000975:Antioxidants / Q000737:chemistry* / Q000494:pharmacology*; D003374:Coumarins / Q000737:chemistry* / Q000494:pharmacology*; D006801:Humans; D008077:Lipoproteins, LDL / Q000737:chemistry*; D015394:Molecular Structure; D010084:Oxidation-Reduction / Q000187:drug effects; D010545:Peroxides / Q000737:chemistry*
D000975:Antioxidants; D003374:Coumarins; D008077:Lipoproteins, LDL; D010545:Peroxides; C049375:perhydroxyl radical