Abstract
It was reported in the previous paper that of the various amines examined for their effect on the anthrone reaction of sugars none except tryptophan had any effect. In the present series of experiment, several substances having structure similar to tryptophan were examined for their effect on the anthrone reaction. Coloration from the reaction between sugar and anthrone was examined in the presence of tryptophan and of other substances, and the color was found to be entirely different. The pigment assumed to have been formed by the reaction of a sugar and anthrone, that pigment added with triptophan, and a pigment formed in the presence of all these three were found to be all different. The color formed in the presence of these three substances at the same time must be a characteristic pigment and its isolation and purification were attempted. The substances thereby isolated was submitted to elemental analysis, molecular weight determination, and examination of properties. A molecular formula was proposed and some considerations were made on its structure.
