Phytyl quinols, namely acyclic tocopherols, are key intermediates of tocopherol biosynthesis,
but their biological activities remain unclear. We therefore investigated the structure-activity
relationship of phytyl quinols to apply a chemical biosynthesis design for an antiatherosclerosis
drug based on isoprenomics. We have achieved the biosynthesis-oriented synthesis of α- and
β-phytyl quinol as an unnatural intermediate, other γ- and δ-phytyl quinol as a natural one. All four
phytyl quinols showed almost the same moderate inhibitory activity against low-density lipoprotein
oxidation instead of their different degree of C-methylation with character different from
tocopherols. In vivo toxicities of phytyl quinols against chick embryo chorioallantoic membrane
vasculature were hardly observed. We proposed phytyl quinols were possible antioxidants in plants
and animals, like vitamin E