W E Schaltenbrand

Modeling Short (7 hour)- and Long (6 week)-Term Kinetics of Vitamin B-6 Metabolism with Stable Isotopes in Humans

The significance and relevance of the topics being discussed in this text is under scored by Westerhoff’s (2000) suggestion that biochemistry is poised to make major advances in this century, similar to those made in physics in the 20th century. He anticipates that, to understand the nonlinear kinetic interactions between molecules and interpret the vast quantities of data becoming available, biochemistry may soon become as computation-intensive as elementary particle physics. The papers in this book should contribute to that process.

Identification of 5'-deoxypyridoxine-3-sulfate as the major urinary metabolite of 5'-deoxypyridoxine in rats with comments on the inhibition of arylsulfatase activity and manganese dioxide oxidation by neighboring groups.

The major urinary metabolite of 5′-deoxypyridoxine in rats was shown to be identical to 5′-deoxypyridoxine-3-sulfate but different from 5′-deoxypyridoxine-4′-sulfate in its ultraviolet and infrared spectra, its migration in thin-layer chromatography, and its behavior in acid and base. Previous identification of the metabolite as 5′-deoxypyridoxine-4′-sulfate by other workers was based on its failure to be hydrolyzed by arylsulfatase and to be oxidized by manganese dioxide. We have now demonstrated that ortho-methyl groups inhibit arylsulfatase and that ortho-sulfate groups inhibit oxidation by manganese dioxide. Therefore, we conclude that under our conditions the major metabolite of 5′-deoxypyridoxine in the rat was the 3-sulfate.