Color reaction of sugars with cysteine. II. Pigment formation from sugars and biological materials.

Among carbohydrates, D-glucose, D-mannose, D-galactose, and glycogen yielded a previously described fluorescent pigment, reddish in alkaline medium and yellowish in acid, when heated with L-cysteine in hydrochloric acid solution. D-Fructose and some pentoses yielded other patients. Among tissue hydrolysates, liver, small intestine, brain, and spleen were found rich in the cysteine pigment but little or none was produced from skeletal muscle, blood, or urine. Among subfractions of rat liver cells, the microsomal fraction proved the richest source of the pigment in nmol/mg protein, though the total yield from the soluble fraction was comparable to that from the microsomal fraction. In the latter fraction, only ribosomal particles yielded the pigment; smooth membrane did not. The pigment yield from yeast was comparable to that from liver. Yield from Escherichia coli K-12 was about one-forth that from yeast.