@misc{oai:repo.qst.go.jp:00070461,
 author = {Nakanishi, Ikuo and Inami, Keiko and Ohkubo, Kei and Kawashima, Tomonori and Matsumoto, Kenichiro and Fukuhara, Kiyoshi and Okuda, Haruhiro and Mochizuki, Masataka and Ikota, Nobuo and Fukuzumi, Shunichi and Ozawa, Toshihiko and Anzai, Kazunori and 中西 郁夫 and 川島 知憲 and 松本 謙一郎},
 month = {Jun},
 note = {The molecular design for novel phenolic antioxidants with high antioxidative and low pro-oxidant activities is of considerable importance with regard to the development of effective chemopreventive agents against oxidative stress and associated diseases.  However, very little is known about the detailed structure-activity relationship of phenolic antioxidants.  In this study, we examined the radical-scavenging rates of alpha-tocopherol and its analogues with various substituents on the 6-chromanol ring.
alpha-Tocopherol efficiently scavenged galvinoxyl radical (GO) with the second-order rate constant (k) of 3.3 x 10(3) M(-1) s(-1) in deaerated acetonitrile at 298 K.  When the phytyl group at the C2 position in alpha-tocopherol was replaced by methyl group, no significant change in the k value was observed (3.2 x 10(3) M(-1) s(-1)).  On the other hand, a carboxyl group at the C2 position significantly retarded the GO-scavenging rate (k = 4.9 x 10(2) M(-1) s(-1)).  Among vitamin E analogues used in this study, 8-amino-2,2-dimethylchroman-6-ol showed the highest GO-scavenging activity (k = 1.4 x 10(4) M(-1) s(-1)).  The logarithm of the k values for alpha-tocopherol and its analogues were linearly correlated with the corresponding ionization potentials (IP) determined by the density functional theory calculations.  The smaller the IP value is, the stronger the radical-scavenging activity becomes., 4th International Symposium on Nutrition, Oxygen Biology and Medicine},
 title = {Substituent Effect on the Radical-Scavenging Reactivity of Vitamin E Analogues},
 year = {2011}
}