Kinobeon A, purified from cultured safflower cells, is a novel and potent singlet oxygen quencher.
We recently reported that kinobeon A, produced from safflower cells, suppressed the free radical-induced damage of cell and microsomal membranes. In the present study, we investigated whether kinobeon A quenches singlet oxygen, another important active oxygen species. Kinobeon A inhibited the singlet oxygen-induced oxidation of squalene. The second-order rate constant between singlet oxygen and kinobeon A was 1.15 x 10(10) M(-1)s(-1) in methanol containing 10% dimethyl sulfoxide at 37 degrees C. Those of alpha-tocopherol and beta-carotene, which are known potent singlet oxygen quenchers, were 4.45 x 10(8) M(-1)s(-1) and 1.26 x 10(10) M(-1)s(-1), respectively. When kinobeon A was incubated with a thermolytic singlet oxygen generator, its concentration decreased. However, this change was extremely small compared to the amount of singlet oxygen formed and the inhibitory effect of kinobeon A on squalene oxidation by singlet oxygen. In conclusion, kinobeon A was a strong singlet oxygen quencher. It reacted chemically with singlet oxygen, but it was physical quenching that was mainly responsible for the elimination of singlet oxygen by kinobeon A. Kinobeon A is expected to have a preventive effect on singlet oxygen-related diseases of the skin or eyes.
Kambayashi
Yasuhiro
Y
Department of Environmental and Preventive Medicine, Graduate School of Medical Science, Kanazawa University, Ishikawa, Japan.
Takekoshi
Susumu
S
Nakano
Minoru
M
Shibamori
Masafumi
M
Hitomi
Yoshiaki
Y
Ogino
Keiki
K
D000475:Alkenes / Q000302:isolation & purification / Q000494:pharmacology*; D031187:Carthamus tinctorius / Q000737:chemistry*; D002478:Cells, Cultured; D010084:Oxidation-Reduction; D026082:Singlet Oxygen; D024505:Tocopherols / Q000494:pharmacology; D019207:beta Carotene / Q000494:pharmacology
D000475:Alkenes; C477467:kinobeon A; D019207:beta Carotene; D026082:Singlet Oxygen; D024505:Tocopherols