  Coronavirus (COVID-19) outbreak in late 2019 and 2020 comprises a serious and
more likely a pandemic threat worldwide. Given that the disease has not
approved vaccines or drugs up to now, any efforts for drug design and or
clinical trails of old drugs based on their mechanism of action are worthy and
creditable in such circumstances. Experienced docking experiments using the
newly released coordinate structure for COVID-19 protease as a receptor and
thoughtfully selected chemicals among antiviral and antibiotics drugs as
ligands may be leading in this context. We selected nine drugs from HIV-1
protease inhibitors and twenty-one candidates from anti bronchitis drugs based
on their chemical structures and enrolled them in blind and active
site-directed dockings in different modes and in native-like conditions of
interactions. Our findings suggest the binding capacity and the inhibitory
potency of candidates are as follows
Tipranavir>Indinavir>Atazanavir>Darunavir>Ritonavir>Amprenavir for HIV-1
protease inhibitors and Cefditoren>Cefixime>Erythromycin>Clarithromycin for
anti bronchitis medicines. The drugs bioavailability, their hydrophobicity and
the hydrophobic properties of their binding sites and also the rates of their
metabolisms and deactivations in the human body are the next determinants for
their overall effects on viral infections, the net results that should survey
by clinical trials to assess their therapeutic usefulness for coronavirus
infections.
