SYNTHESIS AND BIOLOGICAL ACTIVITY OF OXYGENATED DERIVATIVES OF VITAMIN K1 (PEROXIDE, HYDROPEROXIDE, CARBOXYLATION)
Vitamin K(,1) (2-methyl-3-phytyl-1,4-naphthoquinone) was found to react readily at room temperature with peroxyformic and peroxyacetic acids to give a dimeric ketal peroxide, in which the two side chains are connected by a peroxide linkage. Cleavage of the peroxide bond with zinc produced 2'-oxo-3'-hydroxy-vitamin K(,1), the structure of which was confirmed by synthesis. Under more severe conditions, peroxy acids converted vitamin K(,1) into a number of highly unstable, unidentified hydroperoxides.^ Vitamin K(,1)-chromanone-10b-hydroperoxide and vitamin K(,1)-3'-hydroperoxide were highly active as substitutes for vitamin K(,1) in the protein carboxylation reaction. Their activity was not due to conversion to vitamin K(,1) or known metabolites of vitamin K(,1). When corrected for its low stability in microsomes, vitamin K(,1)-3'-hydroperoxide was 9% as effective as vitamin K(,1) in solubilized microsomes containing NADH. This value is 25 times higher than the carboxylation level from the corresponding alcohol derivative, suggesting the possible existence of a hydroperoxide binding site on the carboxylase, and supporting the hypothesis that a hydroperoxide or peroxide derivative of vitamin K(,1) could be an intermediate in the protein carboxylation reaction. ^
THOMAS JOHN NELSON,
"SYNTHESIS AND BIOLOGICAL ACTIVITY OF OXYGENATED DERIVATIVES OF VITAMIN K1 (PEROXIDE, HYDROPEROXIDE, CARBOXYLATION)"
Dissertations and Master's Theses (Campus Access).