ACE2 and COVID-19: Additionally, we have developed a series of other nitro-aminoadamantane compounds, one of which blocks the viroporin ion channel of SARS-CoV-2 and subsequently donates its nitro group to the endogenous viral receptor, ACE2, as the virus approaches the receptor; this blocks binding of the virus to the ACE2 and thus suppresses infection and spread of COVID-19 in the Golden Syrian hamster model in the absence of major side effects (Oh et al., 2022b).