Since the outbreak of the COVID-19 pandemic, it has been obvious that virus infection poses
a serious threat to human health on a global scale. Certain plants, particularly those rich in polyphenols, have been found to be effective antiviral agents. The effectiveness of Alchemilla viridiflora Rothm.
(Rosaceae) methanol extract to prevent contact between virus spike (S)-glycoprotein and angiotensinconverting enzyme 2 (ACE2) and neuropilin-1 (NRP1) receptors was investigated. In vitro results
revealed that the tested samples inhibited 50% of virus-receptor binding interactions in doses of
0.18 and 0.22 mg/mL for NRP1 and ACE2, respectively. Molecular docking studies revealed that the
compounds from A. viridiflora ellagitannins class had a higher affinity for binding with S-glycoprotein
whilst flavonoid compounds more significantly interacted with the NRP1 receptor. Quercetin
3-(6”-ferulylglucoside) and pentagalloylglucose were two compounds with the highest exhibited
interfering potential for selected target receptors, with binding energies of −8.035 (S-glycoprotein)
and −7.685 kcal/mol (NRP1), respectively. Furthermore, computational studies on other SARS-CoV-2
strains resulting from mutations in the original wild strain (V483A, N501Y-K417N-E484K, N501Y,
N439K, L452R-T478K, K417N, G476S, F456L, E484K) revealed that virus internalization activity was
maintained, but with different single compound contributions.
