Nicotinic acid nitroxyalkylamides as NA/K-ATPase inhibitors

The inhibitory action of nicotinamide N-nitroxyalkylamide derivatives (NANDs) on the hydrolase activity of Na/K-ATPase was studied. NANDs contain two peptide bonds and fragments of amides of glycine, β-alanine, α-aminopropanecarboxylic acid, or γ-aminobutyric acid. It is established that the inhibitory effect of NANDs depends on the concentration and hydrophobicity. An increase in the hydrophobicity of NANDs is accompanied by a decrease in their inhibitory action. The most active inhibitor among the studied NANDs is N-nitroxyethylnicotinamide, which noncompetitively and reversibly interacts with Na/K-ATPase with Ki = 2.13 × 10–4 M.