Integration of paper-based colorimetric microdevice and magnetic nanoparticles affinity for high-throughput capture of antimicrobial resistance-reversing agent from complex natural products

Efficient analysis of active ingredient in complex natural products is crucial for drug discovery, but developing a simple method for this is challenging. The discovery of drugs against bacterial resistance is urgent because drug-resistant bacteria produce β-lactamases, which inactivate antibiotics and increase infection risks, particularly the AmpC β-lactamase. Here, an integrated analytical model based on colorimetric sensing and magnetic nanoparticles (MNPs) affinity chromatography was developed for screening AmpC β-lactamase inhibitors. A paper-based colorimetric microdevice was designed for rapid identification of inhibitors in complex samples. Magnetic nanoparticles affinity was then utilized to capture, isolate and identify the active ingredient by immobilized enzyme technology. This comprehensive analytical model greatly improves the efficiency and accuracy of inhibitor screening compared to other screening methods. Finally, the method was applied to screen AmpC β-lactamase activity inhibitors from five natural medicines. As a result, epicatechin gallate, a potential active component of AmpC β-lactamase, was successfully identified from Rhodiola rosea L. After thorough integration with in vitro antibacterial assays, the activity of the screened compounds was further substantiated. Their binding was further explored by molecular docking and molecular dynamics simulations. Consequently, potential AmpC β-lactamase inhibitors are rapidly and precisely captured from complex natural products by this method, which will offer novel insights into the screening of enzyme inhibitors within natural products.