Reactions of 5-amino-3-methylisoxazole-4-carboxylic acid hydrazide with carbonyl compounds: immunological activity and QSAR studies of products.
A series of 4-imino derivatives of the 5-amino-3-methylisoxazole-4-carboxylic acid hydrazide and 5-amino-3-methylisoxazole[5,4-d]-6,7-dihydropyrimidine has been prepared by condensation of 5-amino-3-methylisoxazole-4-carboxylic acid hydrazide with carbonyl compounds. The resulting products were evaluated for their immunological activities in the models of the humoral and cellular immune responses of mice in vivo and concanavalin A (Con A) and lipopolysaccharide (LPS)-induced splenocyte proliferation. In addition, effects on polyclonal antibody production by human peripheral blood cells in culture were investigated. For all studied compounds we carried out quantum chemical calculations at ab initio B3LYP 6-31G(d, p) level. The stimulatory or inhibitory effects depended strongly on the origin and location of substitunets, which is described in the conclusions and was supported by QSAR studies.