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Abstract

The production and purification of indochrome, the soluble pigment from Arthrobacter polychromogenes, is described. Four isomeric 3-hydroxy-6-d-ribosyl-2-aza-benzoquinone-(1,4)-4-[2,6-dihydroxy-5-d-ribosyl-pyridyl-(3)-imides] have been isolated from the natural product as the main components. In indochrome A two β-d-ribopyranosyl residues, in indochrome B II two β-d-ribofuranosyl residues, are bound to the aglycone. The pigment fractions B I and B III contain differently configurated d-ribosyl residues, which for B I were found to be the α- and β-configurations of the pyranose form. Nitric acid degradation of the pigment and condensation with phenylhydrazine yields mainly 3-β-d-ribopyranosyl-5-benzeneazo-2,6-dihydroxy-pyridine. All d-ribopyranosyl residues were found to be in the C1(D) conformation. d-Ribose was liberated from the aglycones by ozonolysis.