Kynurenic acid and its analogues

Tryptophan serves as a rate-limiting essential amino acid and a distinctive building block of peptides and proteins. Many immune system cells are known to be regulated by tryptophan metabolites. Kynurenic acid, an endogenous byproduct of tryptophan metabolism, functions as a wide-spectrum inhibitor of excitatory amino acid receptors and may serve as a protective agent in neurological disorders. Nevertheless, kynurenic acid's efficacy as a neuroprotective drug is considerably constrained by its restricted ability to traverse the blood–brain barrier. Thus, there is a huge demand for novel kynurenic acid analogues that may easily pass through the blood–brain barrier. The production of kynurenic acid is discussed in this article, as well as an overview of the primary novel kynurenic acid analogues, along with their molecular structures and modes of action.