Definition: In this task, you're given a paragraph from the research paper and your task is to generate a suitable title for the research paper based on the given paper. Under 100 words is a good title length.
Input: We describe here the design, synthesis, molecular modeling, and biological evaluation of a series of small molecule, nonpeptide inhibitors of SARS-CoV PLpro. Our initial lead compound was identified via high-throughput screening of a diverse chemical library. We subsequently carried out structure-activity relationship studies, and optimized the lead structure to potent inhibitors that have shown antiviral activity against SARS-CoV infected Vero E6 cells. Based upon the X-ray crystal structure of one of the potent inhibitors 24-bound to SARS-CoV PLpro, a drug-design template was created. Our structure-based modification led to the design of a more potent inhibitor, 2 (enzyme IC 50 = 0.46 μM; antiviral EC 50 = 12.5 μM). Interestingly, its methylamine derivative 49 displayed good enzyme inhibitory potency (IC 50 = 1.3 μM) and most potent SARS antiviral activity (EC 50 = 2.5 μM) in the series. We have carried out computational docking studies and generated a predictive 3D-QSAR model for SARS-CoV PLpro inhibitors.

Structure-Based Design, Synthesis, and Biological Evaluation of a Series of Novel and Reversible Inhibitors for the Severe Acute Respiratory Syndrome-Coronavirus Papain-Like Protease