Synthesis and QSAR of substituted 3-hydroxyanthranilic acid derivatives as inhibitors of 3-hydroxyanthranilic acid dioxygenase (3-HAO)

Novel 4,5-, 4,6-disubstituted and 4,5,6-trisubstituted 3- hydroxyanthranilic acid derivatives were synthesized and their ability to reduce the production of the excitotoxin quinolinic acid (QUIN) by inhibition of brain 3-hydroxyanthranilic acid dioxygenase (3-HAO) was subsequently investigated. The potency of the compounds to inhibit 3-HAO was assayed in rat brain homogenate, while chemical stability of certain compounds was studied by HPLC. The data were used to generate quantitative structure-activity relationship (QSAR) models for potency of 3-HAO inhibition and compound stability. Compounds with longer half-lives were obtained when the difference between the HOMO and LUMO was increased, while electron withdrawing groups in the 4- and 5-positions increased the potency of 3-HAO inhibition. Selected compounds that showed high potency in vitro were also found to be efficacious inhibitors in vivo after cerebral administration in rats. (C) 1999 Editions scientifiques et medicales Elevier SAS.