Interconversion of Activity Peaks in Biochromatograms of Deuterauxin

Abstract

DEUTERAUXIN (DIAA), an oxidation product of indolyl-3-acetic acid (IAA) active in the Avena coleoptile cylinder test¹, is produced as a very thin film on the surface of solutions of IAA (1 g/l.) when they are exposed to ultraviolet irradiation. Physico-chemical investigations of this film have shown that it is mostly made up of molecules of an indole derivative with the intact side-chain of IAA, probably the dimer 2,2′-diindolyl-3,3′-diacetic acid. In chromatograms, DIAA produces an extensive trail, instead of the usual, discrete spot. In double chromatograms (two-dimensional chromatograms in which the same solvent is used in both directions)² the trail has a definite, consistent pattern, characteristic of the solvent, although slight changes in the conditions of equilibration may alter the pattern to a greater or lesser extent.