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This work describes the evaluation of the antioxidant activity in the system b-carotene / linoleic acid and radical scavenging effects of the substances 2',4'-dihydroxychalcone, 2',3,4,4'-tetrahydroxychalcone (butein), 4-methoxy-2',3,4'-trihydroxychalcone, 7-hydroxyflavanone, 3',4',7-trihydroxyflavanone (butin), 7,4'-dihydroxyflavanone (liquiritigenin), 6-methoxy-7-hydroxydihydroflavonol and lasiodiplodin isolated of the extract CHCl3 of the stem of Dioclea violacea and 3',4',5,7-tetrahydroxyflavanol (quercetin), 4',7-dimethoxy-3',5-dihydroxyflavanol and epicatechin isolated of the Erythroxylum nummularia leaves. These compounds were evaluated and compared with the antioxidant standards n-propyl gallate, BHT and α-tocoferol.

DdR,S = deltaR - deltaS) are measured. The determination of the absolute configuration of the alcohol molecule is based on the correlation between its chiral center and the auxiliary reagent's chiral center. Therefore, the determination of the absolute configuration depends on aromatic ring shielding effects on the substituents of the alcohol as evidenced by the ¹H NMR spectrum.]]>