摘要
The oxygen uptake method was used to evaluate the antioxidant activities, , and induction period, tinh, for vitamin E (α-Toc), 2,6-di-tert-butyl-4-methylphenol (BHT), hydroxychromanones (I), dihydroxyxanthenes (II), and hydroxybenzofurans (III) during thermally initiated oxidation of tetralin at 61 °C. 1,3,4,5,6,8-Hexamethylxanthene-2,7-diols IIa–b and 2-ethoxycarbonyl-5,6-dihydroxy-2,3-dihydrobenzofuran IIIc exhibited a lower , and a higher induction period than that for BHT. The higher antioxidant activities of IIa–b and IIIc are mainly attributed to two factors: (i) the p-type lone pair on the ether type oxygen atom can help stabilize the phenoxyl radical formed upon abstraction of the phenolic hydrogen and (ii) the antioxidant activities of IIa–b and IIIc are dependent on the initial hydrogen abstraction from the phenolic OH group as well as on further hydrogen abstraction from the benzylic hydrogen atom or the hydrogen attached to the α-carbon of the ester group.