Figure 5.

Modes of polyphenols binding in the GRP78/SARS-CoV-2 Spike interaction site (Spike side). The binding region of the Spike is colored in orange. The 4 compounds established multiple hydrogen bonds with the residues at the binding region of the Spike. Interactions with Lys-417, Asp-420, Asn-422, and Tyr-421 were observed for all compounds: EGCG (a, a′), homoeriodictyol (b, b′), curcumin (d, d′), except isorhamnetin (c, c′) that established H bonds with Pro-463 and Tyr-505 instead the Asn-420 and Lys-417; EGCG also interacted with Asn-460 and Lys-464. EGCG indicates epigallocatechin gallate; GRP78, glucose-regulating protein 78; SARS-CoV-2, severe acute respiratory syndrome coronavirus 2.