Synthesis and redox potentials of methylated vitamin K derivatives
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.