抄録
Reactions of pyridoxal and related substances, including reaction products of pyridoxal and amino acids or amines reported in the previous paper, with divalent transition metal ions in methanol were examined by electronic absorption spectra. Spectral properties of metal chelates of pyridoxylidene amino acids or amines, pyridoxal and pyridoxamine were described and the shifts of π bands with chelation were discussed. Pyridoxine, carbinolamine from pyridoxal and sarcosine, and imidazotetrahydropyridine derivative from pyridoxal and histidine formed very weak complexes, which could exist only in solutions and under large excess of metal ions. Intramolecular cyclization of pyridoxyli-denehistidine was prevented by chelation with Cu (II). Thiazolidine derivative from pyridoxal and cystamine was oxidized by Cu (II) to give Cu (II) chelate of pyridoxylidene-cystamine.
