Background: COVID-19 which is known as the novel coronavirus was reported in December
2019 in Wuhan city, China and many people have been contaminated by environmental
contamination and transmission from one human to another until now.
Objective: The objective of the present work is to establish the inhibitory potential of nicotiflorin, a
Kaempferol 3-O-rutinoside flavonoid, against the deadly coronavirus (COVID-19) 6W63 (main
protease 3Clpro protein), using molecular docking approach.
Methods: The Molegro Virtual Docker software (MVD) with a 30 Å grid resolution was used. The
structure was drawn by Chem 3D software and energy minimization was done by the MM2 force
field. The protein 6W63 was downloaded from the protein data bank. Molegro modeller was used
for score calculations.
Result: The molecular docking studies were carried out on nicotiflorin and standard inhibitor X77,
where standard inhibitor was observed in a co-crystallized state with main protease 3Clpro protein
6W63. The MolDock score, Rerank Sore, and H Bond score of nicotiflorin and standard inhibitor
X77 were observed as -173.058, -127.302, -21.9398 and -156.913,-121.296,-5.7369, respectively.
Conclusion: Molecular docking studies have confirmed that the affinity of flavonoid nicotiflorin
with the amino acids of the viral protein 6W63 was relatively more than the standard X77. For the
effective treatment of novel coronavirus COVID-19, the effectiveness of the identified flavonoid nicotiflorin
can further be evaluated for safety and efficacy parameters at both preclinical and clinical