Quantitative in silico analysis of SARS-CoV-2 S-RBD omicron mutant transmissibility

Covid-19 variants transmissibility was quantitatively analyzed in silico to understand the reaction mechanisms and to find the reaction inhibitors. Especially, SARS-CoV-2 omicron mutant (omicron S-RBD) binding affinity with human angiotensin-converting enzyme-2 (ACE-2) was quantitatively analyzed using molecular interaction (MI) energy values (kcal^.mol^-1) between the S-RBD and ACE-2. The MI of their optimized complex structures demonstrated that omicron's MI value (749.8) was 1.4 times delta MI (538.1) and 2.7 times alfa MI (276.9). The omicron S-RBD demonstrated the most vital transmissible strength. The 14 currently proposed medical treatment compounds did not show as the inhibitors to block the omicron S-RBD and ACE-2 binding; instead, they adsorbed at the ACE-2 active site and may inhibit the ACE-2 activity. A modified candidate (Gallo catechin gallate) whose two phenolic hydroxy groups were replaced with two carboxy groups was repulsed from ACE-2, indicating that further modification of medical treatment candidates may produce an effective docking inhibitor.