Targeted Oxidation Strategy (TOS) for Potential Inhibition of Coronaviruses by Disulfiram — a 70-Year Old Anti-Alcoholism Drug

In the new millennium, the outbreak of new coronavirus has happened three times: SARS-CoV, MERS-CoV, and 2019-nCoV. Unfortunately, we still have no pharmaceutical weapons against the diseases caused by these viruses. The pandemic of 2019-nCoV reminds us of the urgency to search new drugs with totally different mechanism that may target the weaknesses specific to coronaviruses. Herein, we disclose a new targeted oxidation strategy (TOS II) leveraging non-covalent interactions potentially to oxidize and inhibit the activities of cytosolic thiol proteins via thiol/thiolate oxidation to disulfide (TOD). Quantum mechanical calculations show encouraging results supporting the feasibility to selectively oxidize thiol of targeted proteins via TOS II even in relatively reducing cytosolic microenvironments. Molecular docking against the two thiol proteases Mpro and PLpro of 2019-nCoV provide evidence to support a TOS II mechanism for two experimentally identified anti-2019-nCoV disulfide oxidants: disulfiram and PX-12. Remarkably, disulfiram is an anti-alcoholism drug approved by FDA 70 years ago, thus it can be immediately used in phase III clinical trial for anti-2019-nCoV treatment. Finally, a preliminary list of promising TOS II drug candidates targeting the two thiol proteases of 2019-nCoV are proposed upon virtual screening of 32143 disulfides.