Is mainly found in the cherry bean of the coffee plant, in the tea plant, mate,  and the berries of Guarani. Also we can find it in small amounts in the cacao and the kola nut. Although generally  is found in the seeds, leaves, and fruits of more than 60 plants, in which it acts like a natural pesticide that paralyzes and kills certain classes of insects when they are fed on these. </p>

Caffeine is the most consumed psychoactive substance in the world and it is well known as an stimulant of the central nervous system, which is able to clear drowsiness and can recover the alert level. The drinks that contain caffeine like the coffee, tea, soda and energetic drinks have a great popularity; only in North America 90% of the adults consume caffeine every day.

Chemical properties

It was discovered in 1819 by Ruge and in 1821 by Pelletier and Robiquet.

Caffeine is an alkaloid of the metilxantina´s family, which also includes compounds of teofilina and teobromina, with similar chemical structure. In its pure state it is a very bitter white dust.

Caffeine is a compound alkaloid (of the group of xanthenes) that acts as a stimulant in the humans. It is the same chemical compound that the Guamanian (called thus by Guarani), mateine (by mate) and the theine (by the tea). Originally people thought that these substances had chemical differences, but later it was discovered that they are identical.

 Its chemical formula is C8H10N4O2, their systematic name is 1, 3, 7-trimetilxantina one or 3,7-dihidro-1, 3, 7-trimetil-1H-purina-2, 6-diona and its structure can be seen in the following diagram.