Improved Synthesis of Lysine- and Arginine-Derived Amadori and Heyns Products and in Vitro Measurement of their Angiotensin I-Converting Enzyme Inhibitory Activity

Abstract

The l-lysine- and l-arginine-derived Amadori and Heyns products consisting of <i>N</i>-(1-deoxy-d-fructos-1-yl)­amino acid and <i>N</i>-(2-deoxy-d-glucos-2-yl)­amino acid were prepared by reaction of d-fructose and d-glucose with l-lysine hydrochloride and l-arginine hydrochloride using commercial zinc powder as deprotonating reagent and also as catalyst precursor in a simple synthetic route in high yield. These compounds were screened for angiotensin I-converting enzyme (ACE) inhibitory activity using a high-throughput colorimetric assay (utilizing porcine kidney ACE). The IC₅₀ values fall in the range of 1030–1175 μM, with <i>N</i>^α-(1-deoxy-d-fructos-1-yl)­arginine showing the best IC₅₀ value (1030 ± 38 μM). This study demonstrates an improved synthetic method for simple Amadori and Heyns products and their moderate ACE inhibitor activity