The reduction potential of the β‐carotene +/β‐carotene couple in an aqueous micro‐heterogeneous environment

[摘要]

There is a resurgence of interest in the role of electron transfer reactions involving β-carotene in photosynthesis. There is also current debate on the health benefits of dietary carotenoids and the possible deleterious effects on certain sub-populations such as smokers. The impact of dietary carotenoids on health may well be also related to radical reactions. A key parameter in biological systems is therefore the one-electron reduction potential of the carotenoid radical cation, now reported for the first time in a model biological aqueous environment. The value obtained is 1.06±0.01 V and is sufficiently high to oxidise cell membrane proteins, but is low enough to repair P₆₈₀ ⁺ in the photosynthetic reaction centre.

[学科分类] 生物化学/生物物理

[关键词] β-Carotene;Tryptophan;Tyrosine;Cysteine;One-electron reduction potential