A new class of antibronchospastic agents: 7-(2,2-dimethyl)propyl substituted xanthines

A series of 7-(2,2-dimethyl)propyl substituted xanthines were synthesized and tested for their antibronchospastic activity in comparison with theophylline. In vitro, the inhibition of carbachol-induced increase in bronchial tone was determined. In vivo, the inhibition of antigen-induced bronchoconstriction in guinea pigs was determined 1, 3 and 5 h after oral administration. Central side effects were evaluated. In vitro, the majority of compounds were more effective than theophylline. In vivo, three compounds 2, 14 and 15 showed an effect comparable to theophylline but longer lasting. A mild sedative effect was generally observed. Compound 2, 7-(2,2-dimethyl)propyl-1-methyl xanthine, coded MX2/120, was selected for a deeper evaluation.