Scientifically called tri-methyl-xanthine
Closely linked to the compounds theobromine and theophylline, this odorless compound occurs naturally as a white  powder or as silky needles, and is characterized by a bitter taste. Scientifically called tri-methyl-xanthine, it is very soluble in hot water, and upon cooling deposits crystals of its namesake monohydrate. A member of the alkaloid group,  its toxic oral dosage is 10 grams, and more than half of American adults consume over 3% of that dose daily. A cardiac  stimulant and a mild diuretic having formula C8H10N4O2, FTP name this substance commonly found in guarana, maté,  tea, and coffee.
Closely linked to the compounds theobromine and theophylline, this odorless compound occurs naturally as a white  powder or as silky needles, and is characterized by a bitter taste.
caffeine