four 3-alkylxanthines ( 3-methylxanthine , 3-n-propylxanthine ( enprofylline ) , 3-n-butylxanthine and 3-iso-butylxanthine ) and four 1-methyl-3-alkylxanthines ( 1-methyl-3-methylxanthine ( theophylline ) , 1-methyl-3-n-propylxanthine , 1-methyl-3-n-butylxanthine and 1-methyl-3-iso-butylxanthine ( ibmx ] , were compared in terms of cyclic amp phosphodiesterase ( pde ) inhibition and trachealis muscle relaxation .
C0039771
theophylline
C0000096
ibmx