Solvent-mediated browning of proteins and amino acids

Chemical reactivity of the tryptophan/acetone/DMSO triad system and its potential applications in nanomaterial synthesis

“…These results are consistent with our previous observation that both acetone and DMSO must be present for the browning reaction to occur. 9 The existence of MO in entry 1 was also confirmed through isotope labelling with HR-MS analysis (Fig. S6 † ).…”

“…In our previous investigation, we demonstrated that the extent of l -tryptophan browning is also dependent on the volume fraction of acetone. 9 This underscores the significance of acetone, the simplest and smallest ketone, as a critical reactant resembling the carbonyl compounds involved in the conventional Maillard reaction. However, it is particularly intriguing to observe the reaction between l -tryptophan and acetone in DMSO at room temperature, where no typical catalyst is present.…”

“…The partial reactivity of certain amino acids in the reaction system aligns with our previous findings, which demonstrated significant changes over time in the UV-visible spectra of the amino acid solution. 9 Importantly, it should be noted that, except for l -tryptophan, most amino acids show minimal or no potential for browning. 9 …”

“… 9 Importantly, it should be noted that, except for l -tryptophan, most amino acids show minimal or no potential for browning. 9 …”

“…1 It is a complex series of chemical reactions that occur when a reducing sugar reacts with an amino acid, resulting in the formation of a diverse range of compounds and pigments. 2–8 In our recent investigation, 9 we made an unexpected discovery: intense browning of l -tryptophan in a solvent mixture composed of two commonly used solvents, acetone and dimethyl sulfoxide (DMSO). This novel browning reaction exhibits several distinctive features when compared to the conventional browning reaction.…”