The regiochemistry and stereochemistry of the biosynthesis of vitamin B6 from triose units.

13C and 2H NMR spectroscopy has been employed to probe the biosynthesis of vitamin B6 in Escherichia coli. The 13C NMR spectrum of a sample of pyridoxol derived biosynthetically from D-[1,2,3,4,5,6-13C6]glucose shows that the bonds, C(2)-C(3) and C(4)-C(5), of the pyridine nucleus are the only two carbon-carbon bonds of pyridoxol which are generated de novo in the course of its biosynthesis from glucose. It follows that the pyridoxol skeleton …