Discovery and Pharmacological Studies of 4-Hydroxyphenyl-Derived Phosphonium Salts Active in a Mouse Model of Visceral Leishmaniasis

We report the discovery of new 4-hydroxyphenyl phosphonium salt derivatives active in the submicromolar range (EC50 from 0.04 to 0.28 μM, SI > 10) against the protozoan parasite Leishmania donovani. The pharmacokinetics and in vivo oral efficacy of compound 1 [(16-(2,4-dihydroxyphenyl)-16-oxohexadecyl)triphenylphosphonium bromide] in a mouse model of visceral leishmaniasis were established. Compound 1 reduced the parasite load in spleen (98.9%)...