a white, crystalline, almost water-soluble, alkaloidal purine derivative, C 5 H 4 N 4 O, found in animal and vegetable tissues: used chiefly in biochemical research.
a white, crystalline, nonnarcotic, alkaloidal powder, C 2 0 H 2 1 NO 4 , obtained from opium, but not a morphine derivative and not habit-forming or addicting, used in the treatment of spasms of involuntary muscle, especially of the stomach, bronchi, and arteries.
