Microflow-based dynamic combinatorial chemistry: a microscale synthesis and screening platform for the rapid and accurate identification of bioactive molecules

Protein-directed dynamic combinatorial chemistry (DCC) has emerged as an efficient tool for the rapid identification of bioactive molecules in modern drug discovery. However, the applications of protein-directed DCC have been significantly hampered by (i) the poor reactivity of potential inhibitors at low concentration; (ii) the reduction of protein activity or the decomposition of potential inhibitors owing to long equilibration times; and (iii) limited analytical detection methods capable of processing large libraries. Here we report the development of a rapid flowbased synthesis and screening platform that integrates both microscale synthesis and identification of protein binders from protein-directed dynamic libraries into a single modular unit. By using microflow synthesis, the processes of compound synthesis and binding to the target protein were accelerated, and the accuracy of identification of potential inhibitors was improved. This system was validated by a case study that identified competitive inhibitors of bovine serum albumin (BSA). A significant reduction in equilibration time and an increased sensitivity for the identification of protein binders were acquired. Owing to the microscale effect, a new inhibitor for BSA, which was not found in batch mode, was discovered in the microflow system and the interaction of the new binder with BSA was also investigated.