Decarboxylase inhibition and structure-activity relationship studies with some newly synthetized benzyloxyamine and pyridylmethoxyamine derivatives

Abstract

Decarboxylase inhibiting properties and the structure-activity relationship have been studied with a number of newly synthetized benzyloxyamines and pyridylmethoxyamines. In the case of benzyloxyamines, the 3-hydroxyl group, and in that of pyridylmethoxyamines, the position of methoxyamine group in the molecule, appear to be of special importance for inhibition of aromatic l-amino acid decarboxylase. We did not find any close relationship between specific histidine decarboxylase inhibiting effect and chemical structure. 3-Hydroxy-4-nitrobenzyloxyamine and pyridyl-3-methoxyamine were the most active compounds in these series. The former compound affected markedly both aromatic l-amino acid decarboxylase and histidine decarboxylase in vitro and in vivo and produced a significant decrease in the levels of histamine in the stomach and in the lungs. The latter compound proved to be a specific inhibitor of histidine decarboxylase and had a more pronounced effect on the tissue histamine levels than most of new and old benzyloxyamine derivatives.