Ethylhydrocupreine hydrochloride (Optochin hydrochloride) is a derivative of quinine with antimicrobial activity against Streptococcus pneumoniae.Ethylhydrocupreine hydrochloride has antimalarial activity with an IC50 of 25.75 nM for Plasmodium falciparum. Ethylhydrocupreine hydrochloride has antimalarial activity with an IC50 of 25.75 nM against Plasmodium falciparum.Ethylhydrocupreine hydrochloride is an agonist of Gallus gallus2 receptors (ggTas2r1, ggTas2r2 and ggTas2r7).