Urinary l‐kynurenine quantification and selective extraction through a molecularly imprinted solid‐phase extraction device. Issue 16 (11th July 2018) - Mergola, Lucia
Abstract: l ‐Kynurenine is an endogenous metabolite generated by the catabolic pathway ofl ‐tryptophan and it could be a potential biomarker to test the efficacy of several checkpoint inhibitors that have already reached the clinical trials in the antitumor therapy. Thus, a molecularly imprinted polymer specific for the recognition of this metabolite was synthesized and used as innovative system in solid‐phase extraction technique for the specific extraction and quantification ofl ‐kynurenine in human urine. The off‐line system was firstly tested onl ‐kynurenine standard solutions, allowing recoveries up to 97.7% (relative standard deviation = 2.2%) and then applied to fortified and deproteinated human urine samples, where a recovery of 84.1% (relative standard deviation = 3.1%) was obtained. The method was validated and it revealed a good linearity in the range of 0.157–20 μg/mL ( r 2 = 0.9992). The optimized procedure demonstrated a good feasibility on biological samples, allowing a ready quantification ofl ‐kynurenine in the human urine, where the metabolite was found at a very low concentration (0.80 μg/mL). The extraction system developed could attract attention of pharmaceutical industries forl ‐kynurenine production as potential drug in the treatment of autoimmune disorders through its extraction and purification from biological matrixes.