Synthesis and redox potentials of methylated vitamin K derivatives

Abstract

We report the synthesis of derivatives of vitamin K₃ as well as of vitamins K₁ and K₂ containing a different number of methyl groups in various positions in order to reduce their redox potentials and to change systematically their steric features. The long aliphatic chain of vitamins K₁ and K₂ is simulated by an undecyl chain or a methyl group, respectively. The redox potentials of the first reduction step were measured by cyclic voltammetry in DMF. These compounds are relevant for studies of the structure–function relationship of vitamin K dependent enzymes and the investigation of electron transfer reactions in photosynthetic reaction centers.