Amquinate

Amquinate is a coccidiostat and a cytochrome b inhibitor. Amquinate blocks cytochrome-mediated electron transport near cytochrome b in mitochondria, acting downstream of coenzyme Q without affecting succinate dehydrogenase or NADH dehydrogenase. Amquinate inhibits succinate- and malate plus pyruvate-supported mitochondrial respiration in Eimeria tenella and does not affect L-ascorbate-supported respiration or any mitochondrial respiration in chicken liver mitochondria. Amquinate exhibits selective anticoccidial activity against wild-type Eimeria tenella. Amquinate can be used for the research of coccidiosis (Eimeria tenella infection)^[1]. In Vitro:Amquinate potently inhibits succinate- and NADH-supported respiration in wild-type Eimeria tenella mitochondria with an IC₅₀ of 1×10^-8 M, has no effect on chicken liver mitochondrial respiration at concentrations >1×10^-3 M, and does not inhibit succinate dehydrogenase-CoQ reductase or NADH dehydrogenase-CoQ reductase activities at 1×10^-4 M^[1].
Amquinate shows 100-fold reduced sensitivity in mitochondria from the amquinate-resistant Eimeria tenella mutant, with an IC₅₀ of 1×10^-6 M for succinate-supported respiration^[1]. In Vivo:Amquinate (30 ppm; diets) exhibits in vivo anticoccidial activity against wild-type Eimeria tenella in chickens, with a minimal effective dietary dose of 30 ppm^[1].
Amquinate (2000 ppm; diets) requires a 66.7-fold higher minimal effective dietary dose (2000 ppm) to exhibit anticoccidial activity against amquinate-resistant Eimeria tenella mutant infection in chickens compared to wild-type parasites^[1].