Interaction of certain monoterpenoid hydrocarbons with the receptor binding domain of 2019 novel coronavirus (2019-nCoV), transmembrane serine protease 2 (TMPRSS2), cathepsin B, and cathepsin L (CatB/L) and their pharmacokinetic properties

As of June 2020, the coronavirus disease 19 (COVID-19) caused by the 2019 new type coronavirus (2019-nCoV) infected more than 7,000,000 people worldwide and caused the death of more than 400,000 people. The aim of this study was to investigate the molecular interactions between monoterpenoids and spike protein of 2019-nCoV together with the cellular proteases [transmembrane serine protease 2 (TMPRSS2), cathepsin B (CatB), and cathepsin L (CatL)]. As a result of the relative binding capacity index (RBCI) analysis, carvone was found to be the most effective molecule against all targets when binding energy and predicted (theoretical) IC50 data were evaluated together. It was found to exhibit drug-likeness property according to the Lipinski's rule-of-five. Carvone has also been determined to be able to cross the blood-brain barrier (BBB) effectively, not a substrate for P-glycoprotein (P-gp), not to inhibit any of the cytochrome P molecules, and to have no toxic effects even on liver cells. In addition, the LD50 dose of carvone in rats was 1.707 mol/kg. Due to its interaction profile with target proteins and excellent pharmacokinetic properties, it has been concluded that carvone can be considered as an alternative agent in drug development studies against 2019-nCoV.