Pharmacological activities of a homologous series of pyrazole derivatives including quantitative structure-activity relationships (QSAR).
Manfred Paintz, H Bekemeier, J Metzner, Udo Wenzel · PubMed · 1982
In a series of fourteen 1-benzoyl-3-methyl-pyrazole derivatives the antiinflammatory activity in the carrageenin edema of the rat paw was found to be in the potency range of that of aminophenazone. This holds also true of the analgesic, anticonvulsive, and anticholinergic activity of the compounds whereas antihistaminergic activity was 10-fold better and acute toxicity was less than that of aminophenazone. Using the MASCA model as a multivariate method in QSAR the regression matrix of the derivatives substituted in p-position of the benzoyl moiety has been calculated. According to that, all of the biological activities are mainly described in terms of pi, sigma, xi, and L. The increase of inflammatory activity could be expected by substitution of electro-positive substituents of short length (L) and little relative surface tension (xi). Concomitantly, analgesic and anticonvulsive activities could increase whereas anticholinergic and antihistaminergic activities are expected to decrease. The HANSCH analysis is surely to be preferred in investigations of the relationship between physicochemical parameters of compounds and a certain biological activity evoked by them. However, the multivariate MASCA model could be of some advantage in the optimization of chemical structure against the whole profile of biological activities in a series of compounds. Some problems of the MASCA model are briefly discussed.