The assay was conducted using a Biacore™ 8K (Cytiva) at 20 °C. Biotinylated Nsp13_SARS2, with approximately 4900-5100 response units (RU), was immobilized onto the flow cell two of a streptavidin-conjugated streptavidin chip following the manufacturer's protocol. The flow cell one served as a reference for subtraction for each channel. Compounds were initially dissolved in 100% DMSO to create 10 mM stock solutions, which were subsequently serially diluted (factor: 0.5) to obtain six concentration points in 100% DMSO. For the SPR run, these serially titrated compound stocks were diluted at the ratio 1:50 in HBS buffer, containing Mg2+ (10 mM HEPES pH 7.4, 150 mM NaCl, 5 mM MgCl2, 0.03% (v/v) Tween 20) to achieve a final DMSO concentration 2%. Binding experiments used multi-cycle kinetics with a contact time of 60 seconds and a dissociation time of 180 seconds at a flow rate of 40 µL/min at 20 °C. The dissociation constant (KD) values were determined using steady-state affinity 1:1 binding with the Biacore™ Insight Evaluation software (Cytiva).