The coenzyme of the galactowaldenase system which catalyzes the conversion of galactose-1-phosphate into glucose-1-phosphate. Isoln from baker's yeast: Caputto et al., J. Biol. Chem. 184, 333 (1950). Also present in animal tissue. Synthesis: Michelson, Todd, J. Chem. Soc. 1956, 3459; Moffatt, Khorana, J. Am. Chem. Soc. 80, 3756 (1958). Reviews: Leloir, Cardini in The Enzymes vol. 2A, P. D. Boyer et al., Eds. (Academic Press, New York, 2nd ed., 1960) pp 39-61; A. M. Michelson, The Chemistry of Nucleosides and Nucleotides (Academic Press, New York, 1963) pp 153-250; D. W. Hutchison, Nucleotides and Coenzymes (John Wiley, New York, 1964) pp 36-82.