The entire extracellular domain (ECD), a soluble form of both receptors, was used to maintain their tetramerized state for ligand evaluation. Given the size of the ligands and their potential low affinity for lectins, monovalent ligands were evaluated using a competition assay for binding to the SARS-CoV-2 spike protein. In this SPR assay recently described Comparison of the inhibition curves (Fig. ) indicates that there is no difference in the inhibitory potential of Man79 towards either of the lectins, given the similarity of the IC50 values obtained towards DC-SIGN and L-SIGN (318 and 278 µM respectively). However, these values are 10 times lower than the natural mannose residue (IC50 ~ 2-3 mM), confirming that the addition of this 2-triazol-amino group at C2 is highly efficient in raising affinity for both lectin sites, while it does not induce any selectivity, as already described . This compound is a monosaccharide derivative of a previously characterized disaccharide glycomimetic where the amine has been shown to reach a specific pocket, in proximity to the calcium binding site of DC-SIGN , made of the F313, E358 and S360 binding triad in DC-SIGN.