PIDA-Mediated Synthesis of Kynurenine Derivatives by Oxidative Fragmentation of Tryptophan Scaffold

Abstract

Kynurenine metabolite is derived from aromatic amino acid tryptophan and its chemical synthesis has been sought for understanding the tryptophan-kynurenine based biochemical reactions that could provide opportunity for exploring therapeutic values. This report describes the synthesis of kynurenine (kyn) derivatives from tryptophan containing peptides with versatile hypervalent iodine reagent, Phenyliodine(III) diacetate (PIDA), through the C‒C bond fragmentation of tryptophan’s indole ring. However, BocNH-Trp-OH and N-arylated (both benzenoid and non-benzenoid) tryptophan derivatives produce unique spirocyclic molecules under similar reaction conditions with PIDA. In screening of therapeutic values, the sequence specific kynurenine derivatives show quorum sensing inhibition against multidrug-resistant pathogenic bacteria Pseudomonas aeruginosa PA14 strain.