Inhibition of Lipid Peroxidation by Plastoquinol and Other Prenyllipids

摘要

Besides tocopherols, plastoquinol-9 and plastochromanol-8 are antioxidant prenyllipids whose level is increased during high light stress of plants as a response to elevated production of reactive oxygen species during the stress. Recently, it was demonstrated in several studies that these prenyllipids are effective singlet oxygen scavengers both in vitro and in vivo. These compounds are also able to inhibit lipid peroxidation -a radical chain reaction, which is responsible for destruction of membrane lipids. Here we present the comparative data on the inhibition of lipid peroxidation by plastoquinol-9, plastochromanol-8, a-tocopherol and a other prenyllipids. We observed that when lipid peroxidation was initiated within membranes, the long-chain, hydrophobic prenyllipids such as plastoquinol-9 and plastochromanol-8 were considerably more active than tocopherols in the inhibition of the peroxidation reaction, whereas lipid peroxidation was generated in the water phase, tocopherols and plastochromanol-8 were more effective than the other prenyllipids.