Quantitative structure-activity relationship study on N-(pyridin-4-yl)-(indol-3-yl) alkylamides as antiallergic agents

The antihistamine activity of N-(pyridin-4-yl)-(indol-3-yl) alkylamides has been analyzed using Fujita-Ban and Hansch approaches. The analyses have helped to ascertain the role of different substituents in explaining the antiallergic actions of these analogues. From both approaches it is revealed that the small size substituents at R and R2 and non-hydrogen bond acceptor substituent at R improve histamine antagonist activity of a compound. Likewise, a small incision such as -CH2CONH-serving as the spacer between pyridinyl and indolyl rings and a bigger substituent like 4-FBn at R1 are also desirable for inhibitory activity.