Introducting of the 3-deoxy group in 3,6-dideoxyhexoses: a novel cofactor function for pyridoxamine-5'-phosphate

A cofactor needed for the reduction of CDP-4-keto-6-deoxy-D-glucose to CDP-4-keto-3,6-dideoxy D-glucose has been detected and purified. Its spectra in neutral, acid, and basic solutions, its behavior on thin-layer chromatography, and other properties led to its identification as pyridoxamine-5'-phosphate. Moreover, authentic pyridoxamine-5'-phosphate substituted for the purified cofactor with about the same specific activity. Other vitamin B(6) derivatives did not stimulate the reaction, and inhibition was observed with some of them.