Indole Compounds Synthesized by Diplodia natalensis

Abstract

Diplodia natalensis Pole-Evans was grown aerobically in synthetic medium with or without added tryptophane or tryptamine. Chromatographic and spectrophotometric techniques were used to separate and identify the indole compounds produced by this organism. Indoleactic acid (IAA) was found to be a metabolic product in the absence of added precursor and was the only indole compound detected which possessed growth-promoting properties. When tryptamine was added to the medium in was readily converted to IAA. Chromatograms of the mycellium which had grown in the tryptamine supplemented medium revealed a strong IAA spot. Using TTP 2[image]C14 it was determined that indolelactic acid is the predominant end product when trypto-phane is added to the culture medium, and only small amounts of IAA are synthesized. Another indole compound, tentatively identified as tryptophol, was present in the extracts from both the tryptamine and tryptophane media.