Isolation and Identification of Novel Taste-Modulating N²-Guanosine 5′-Monophosphate Derivatives Generated by Maillard-Type Reactions

Several compounds with taste-modulating properties have been investigated, improving the taste impression without having a pronounced intrinsic taste. The best-known representatives of umami taste-modulating compounds are ribonucleotides and their derivatives. Especially the thio derivatives showed high taste-modulating potential in structure-activity relationship investigations. Therefore, this study focuses on the formation of guanosine 5′-monophosphate derivatives consisting of Maillard-type generated compounds like the aroma-active thiols (2-methyl-3-furanthiol, 3-mercapto-2-pentanone, 2-furfurylthiol) and formaldehyde to gain insights into the potential of combinations of taste and aroma-active compounds. One literature-known (N²-(furfurylthiomethyl)-guanosine 5′-monophosphate) and three new derivatives (N²-(2-methyl-1-furylthiomethyl)-guanosine 5′-monophosphate, N²-((5-hydroxymethyl)-2-methyl-1-furylthiomethyl)-guanosine 5′-monophosphate, N²-((2-pentanon-1-yl)thiomethyl)-guanosine 5′-monophosphate) were successfully produced using green natural deep eutectic solvents and isolated, and their structures were completely elucidated. Besides the intrinsic taste properties, the kokumi and umami taste-modulating effects of the four derivatives were evaluated via psychophysical investigations, ranging from 19 to 22 μmol/L.