Green Synthesis of Catechol Probe via Amide Coupling Reaction

Catechols have had an upsurge in popularity recently due to their proclaimed antioxidant benefits, and yet the mechanisms of their interactions with proteins in the body are still incompletely understood. In this study, we are investigating the interaction of catechols with several target enzymes by visualization with a catechol probe susceptible to nucleophilic attack by cysteine residues upon oxidation. This probe, which includes an alkyne handle, should make visualization of the reaction fairly straightforward and will aid in clarifying the more precise nature of the interactions between catechols and common enzymes present in E. coli cells. The main focus of this stage of the study is constructing a “Greener” procedure for the synthesis of the catechol probe in order to reduce usage of environmentally harmful reagents such as DMF, DCM, and HOBt used in previous syntheses of a similar catechol probe. We are experimenting with Cyrene as a green substitute for DMF and Oxyma Pure as a less explosive carboxylic acid activator substitute for HOBt. Reactions involving the use of Cyrene as a solvent and Oxyma Pure have been attempted before with respect to amide coupling in peptide syntheses, but the synthesis of a catechol probe, specifically, using Green Chemistry is an exciting new area that offers bright prospects for health-related applications.