Metabolites Derived from Tryptophan and Alanine

Diketopiperazine Metabolites Derived from Tryptophan and Alanine 

Since the discovery of echinulin in 1943, many fungal metabolites having a 

5-diketopiperazine moiety have been isolated. Since 1970, this group has attracted interest, particularly due to the isolation of many biologically active metabolites such as austamide, fumitremorgen, and tryptoquivaline. In most cases, the diketopiperazine ring of fungal metabolites utilizes tryptophan as one of the components. In this section fungal metabolites composed of tryptophan and alanine are described. 

Pyrolysis of the potassium salt of hydrogenated echinulin affords a viscous liquid, C23H37N (13), which is positive to Ehrlich reaction and classified as a 

7-trisubstituted indole by comparing the UV and IR spectra. KOH hydrolysis of hydroechinulin gives hydroechinin (14). Oxidation of 14 with peracetic acid affords substituted A -acylanthranilic acid which is hydrolyzed with alcoholic KOH to give 1,1-dimethylbutyric acid and disubstituted anthranilic acid. The 

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III. Diketopiperazine Metabolites Derived from Tryptophan and Alanine... 

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