Theobromine
Theobromine
OVERVIEW
Theobromine (thee-oh-BROH-meen) is a white crystalline solid that occurs naturally in cocoa beans, from which chocolate is obtained, and, in smaller amounts, in tea and cola nuts. Theobromine is structurally very similar to caffeine, which differs only in the presence of a methyl group (−CH3) on one of the nitrogen atoms in the theobromine molecule. Both theobromine and caffeine belong to a family of organic compounds known as the methylxanthines. Theobromine's effects on the human body are similar to those of caffeine, but about ten times weaker. In addition, caffeine is metabolized more quickly, is addictive, and increases alertness and emotional stress. It may also have serious effects on the central nervous system and the kidneys. By contrast, theobromine produces feelings of well-being, is not addictive, has no effect on the central nervous system, and provides only gentle stimulation to the kidneys. Its effects on the body are much longer-lasting than are those of caffeine.
KEY FACTS
OTHER NAMES:
3,7-Dimethylxanthine; 3,7-dihydro-3,7-dimethyl-1H-purine-2,6-dione
FORMULA:
C7H8N4O2
ELEMENTS:
Carbon, hydrogen, nitrogen, oxygen
COMPOUND TYPE:
Alkaloid (organic base)
STATE:
Solid
MOLECULAR WEIGHT:
180.16 g/mol
MELTING POINT:
Begins to sublime at about 290°C (554°F)
BOILING POINT:
Not applicable
SOLUBILITY:
Slightly soluble in water and ethyl alcohol; virtually insoluble in benzene, chloroform, ether, and other organic solvents
The amount of theobromine in cocoa beans varies widely, ranging from 10 to 40 milligrams of theobromine per gram of cocoa. The variation depends on a number of facts, including the type of bean, the location where it was grown, and the method of processing the bean. All chocolate products contain theobromine, but the amount varies depending on the type of chocolate. Dark chocolate contains significantly more of the compound than milk chocolate, and high quality chocolate tends to contain more theobromine than low quality chocolate. The characteristic bitter taste of dark chocolate is due to the theobromine present in it.
HOW IT IS MADE
Theobromine is usually obtained from the hulls of cocoa beans left over after the production of chocolate. The hulls are crushed and then treated with an absorbent, such as water or liquid carbon dioxide, which dissolves the theobromine. The water or carbon dioxide is then allowed to evaporate, permitting the crystallization of the pure compound.
Interesting Facts
- The name theobromine is derived from the scientific name for the cacao tree, Theobroma cacao.
- Spanish armies that invaded South and Central America in the sixteenth century used chocolate as a source of energy.
- Theobromine is harmless to humans, but very toxic to dogs, horses, and other domestic animals.
Words to Know
- DIURETIC
- A compound that increases the rate at which liquids are eliminated from the body.
- METHYLXANTHINE
- A compound that is derived from xanthine (C5H4N4O2), with methyl groups (CH3) replacing one or more of the hydrogen atoms.
- STIMULANT:
- A substance that increases the activity of a living organism or one of its parts.
- SUBLIME
- To go from solid to gaseous form without passing through a liquid phase.
COMMON USES AND POTENTIAL HAZARDS
Theobromine occurs in all chocolate products. The pure compound has relatively few uses, however, most of them medical. For example, it has been used as a diuretic—a compound that increases the rate at which liquids are eliminated from the body—and as a mild stimulant. It has also been used to treat hypertension (high blood pressure) because it is a vasodilator, a compound that causes blood vessels to relax and expand in size. Theobromine also appears to be effective as a cough suppressant, although the quantities needed to achieve useful effects are quite large.
FOR FURTHER INFORMATION
O'Neil, John. "And It Doesn't Taste Bad, Either." New York Times (November 30, 2004): F9.
"[email protected]." Molecule of the Month. http://www.3dchem.com/molecules.asp?ID=155 (accessed on November 15, 2005).
"What Is Theobromine and What Is Its Effect on Human Beings?" International Cocoa Organization. http://www.icco.org/questions/theobromine.htm (accessed on January 11, 2006).
See AlsoCaffeine; Carbon Dioxide.
Theobromine
THEOBROMINE
This Alkaloid belongs to the class of drugs called methylxanthines; it is similar to theophylline and to Caffeine. Theobromine (3, 7-dimethylxanthine), however, is somewhat weaker than these two compounds and currently has almost no practical use in medicine.
Theobromine is found in the seeds of the plant Theobroma cacao, which is the well-known source of Chocolate and cocoa. The cacao seeds have caffeine too (as does Tea, which contains small amounts of theobromine and theophylline); caffeine has powerful stimulant effects on the brain, whereas theobromine has very little (although popular articles alleged for years that theobromine makes one feel "happy"). High doses of theobromine can, however, affect several physiological functions in the body, such as increasing the formation of urine in the kidney.
BIBLIOGRAPHY
Serafin, W. E. (1996). Drugs used in the treatment of asthma. In J. G. Hardman et al. (Eds.), The Pharmacological Basis of Therapeutics, 9th ed. (pp. 659-682). New York: McGraw-Hill.
Michael J. Kuhar