New types of bronchodilator agents, bi- and tricyclic nitrogenbridgeheadcompounds with a pyrimidin-4(3H)-one ring, were synthesized and evaluated for bronchodilator activity against serotonin-, histamine-, and acetylcholine-induced spasms in the guinea pig Konzett-Rössler test. The structure-activity relationships are discussed. The effects of some bi- and tricyclic derivatives on the human bronchus
The series of vasicine ( 1 ) analogues, an alkaloid from Adhatoda vasica Nees., were synthesized with changes in A, B or C rings. Compounds 13-19 were evaluated for in vitro bronchodilatory activity using isolated guinea pig tracheal chain. Compounds 3-8 were also synthesized in good yields using microwave-mediated synthesisundersolventfreeconditions. Compounds 5 and 8 with seven-member C ring