7979. Pyridoxal 5-Phosphate
Nomenclature
Description and references
Prepn by the action of adenosine triphosphate on pyridoxal: Gunsalus et al., J. Biol. Chem. 155, 685 (1944); by the action of phosphorus oxychloride on pyridoxal in aq soln: Gunsalus et al., ibid. 161, 743 (1945); Umbreit et al., Arch. Biochem. 7, 189 (1945); by phosphorylation of pyridoxamine with 100% H3PO4 followed by oxidation: Wilson, Harris, J. Am. Chem. Soc. 73, 4693 (1951). Alternate route: Schorre, US 3124587 (1964 to E. Merck). Isoln in pure form as the oxime and as the O-methyl oxime and structure: Heyl et al., J. Am. Chem. Soc. 73, 3430 (1951). Activity as a cotransaminase in the synthesis of amino acids: Lichstein et al., J. Biol. Chem. 161, 311 (1945). Activity of natural and synthetic material: Umbreit et al., loc. cit.
Properties
Colorless in acid soln, bright-yellow in alkaline soln. uv max (alkaline soln): 390 nm (Em 3.7); in acid soln: 295 nm (Em 5.1). Gives a negative 2,6-dichloroquinone chlorimide test. On oxidation with H2O2 in alkaline solution yields [(2-methyl-3,4-dihydroxy-5-pyridyl)methyl]phosphoric acid.Derivative
Oxime.Nomenclature
Properties
Crystals, dec 229-230°. Practically insol in water, alcohol, ether.Derivative
O-Methyloxime.Nomenclature
Properties
Crystals, dec 212-213°. Practically insol in water, alcohol, ether.Derivative
Calcium salt.Nomenclature
Properties
Yellow precipitate. Practically insol in water, alcohol or ether.Therapeutic Category
Vitamin (enzyme co-factor).
Keywords
Enzyme Cofactor; Vitamin/Vitamin Source; Vitamin B6