Caffeine is a xanthine alkaloid compound and a stimulant of central nervous system, which can temporarily dispel drowsiness and restore energy. It is used to treat neurasthenia and coma and resuscitation in clinic. Coffee, tea, soft drinks and energy drinks containing caffeine are very popular, so caffeine is also the most widely used psychotropic drug in the world.
Extended data:
Caffeine is a plant alkaloid, which exists in many plants. As a natural insecticide, it can paralyze insects that devour caffeinated plants. Caffeine-containing plants commonly used by human beings include coffee, tea and some cocoa. Other less commonly used trees include Paraguayan holly and guana trees, which are usually used to make tea or energy drinks. Two nicknames of caffeine: Madeleine and Guanana factor evolved from these two plants.
The main source of caffeine in the world is coffee bean (the seed of coffee tree), and coffee bean is also the raw material of coffee. The caffeine content in coffee depends largely on the variety of coffee beans and the method of making coffee, and even the caffeine content in coffee beans on the same tree is quite different. Generally speaking, the content of caffeine in a cup of coffee ranges from 40 mg espresso to 100 mg espresso. Deep roasted coffee generally contains less caffeine than lightly roasted coffee, because roasting can reduce the caffeine content in coffee beans. The caffeine content of Arabian coffee is usually lower than that of Chinese coffee. Coffee also contains a trace of theophylline, but does not contain theobromine.
References:
Baidu encyclopedia-caffeine