  SARS-COV-2 identified as COVID-19 in Wuhan city of China in the month of
December, 2019 has now been declared as pandemic by World Health Organization
whose transmission chain and cure both have emerged as a tough problem for the
medical fraternity. The reports pertaining to the treatment of this pandemic
are still lacking. We firmly believe that Nature itself provides a simple
solution for any complicated problem created in it which motivated us to carry
out In Silico investigations on some bioactive natural compounds reportedly
found in the fruits and leaves of Anthocephalus Cadamba which is a miraculous
plant found on the earth aiming to predict the potential inhibitors against
aforesaid virus. Having modeled the ground state ligand structure of the such
nine natural compounds applying density functional theory at B3LYP/631+G (d, p)
level we have performed their molecular docking with SARS-COV-2 protease to
calculate the binding affinity as well as to screen the binding at S-protein
site during ligand-protein interactions. Out of these nine studied naturally
occurring compounds; Oleanic Acid has been appeared to be potential inhibitor
for COVID-19 followed by Ursolic Acid,
IsoVallesiachotamine,Vallesiachotamine,Cadambine,Vincosamide-N-Oxide,
Isodihydroamino-cadambine, Pentyle Ester of Chlorogenic Acid and
D-Myo-Inositol. Hence these bioactive natural compounds or their structural
analogs may be explored as anti-COVID19 drug agent which will be possessing the
peculiar feature of cost-less synthesis and less or no side effect due to their
natural occurrence. The solubility and solvent-effect related to the
phytochemicals may be the point of concern. The In-vivo investigations on these
proposed natural compounds or on their structural analogs are invited for
designing and developing the potential medicine/vaccine for the treatment of
COVID-19 pandemic.
