Guarana, caffeine

C8H10N4O2. An alkaloid occurring in tea, coffee and guarana, from which it may be prepared by extraction, It is also manufactured by the methylation of theobromine and by the condensation of cyanoacetic acid with urea. Crystallizes with H2O or anhydrous from organic solvents. M.p. (anhydrous) 235"C, sublimes at 176 C. Odourless, and with a very bitter taste. Caffeine acts as a stimulant and diuretic, and is a constituent of cola drinks, tea and coffee. 

The analysis of the methylxanthines (caffeine, theobromine, and theophylline) is important in the areas of nutrition and clinical chemistry. These three compounds compose the majority of the alkaloids present in coffee, tea, cocoa, cola nuts, and guarana. 

Guarana contains tetra methylxanthine, a compound almost identical to caffeine and other stimulants such as theophylline (which has been isolated and sold as a drug and which can be toxic when consumed in high doses), theobromine, and saponins. Although not well documented, the side effects of guarana are similar to those of other stimulants. 

Alkaloids are compounds that contain nitrogen in a heterocyclic ring and are commonly found in about 15-20% of all vascular plants. Alkaloids are subclassified on the basis of the chemical type of their nitrogen-containing ring. They are formed as secondary metabolites from amino acids and usually present a bitter taste accompanied by toxicity that should help to repel insects and herbivores. Alkaloids are found in seeds, leaves, and roots of plants such as coffee beans, guarana seeds, cocoa beans, mate tea leaves, peppermint leaves, coca leaves, and many other plant sources. The most common alkaloids are caffeine, theophylline, nicotine, codeine, and indole... 

Alkaloids such as caffeine and theobromine were obtained from cocoa beans and guarana seeds (Saldana and others 2002a,b). 

Temperature and pressure. Most of the nut and seed studies on extractions of phytochemicals using SC-CO2 were performed at a temperature range of 35-80°C and a pressure range of 10-70 MPa (see Table 9.3). The effects of pressure and temperature were studied in the removal of caffeine from wet ground guarana seeds at 40 and... 

Caffeine, 1,3,7-trimethylxanthine, is the major alkaloid, occms in teaplants, coffee, guarana, cola nuts, cocoa beans, mate and other plants. It is a powerful stimirlant of the central nervous system and also stimirlates the cardiac muscle. However, high... 

The principal psychoactive constituent of guarana is caffeine (2.5-5%), although theobromine and theophylline are present in smaller amounts (Gruenwald et al. 1998). Depending on the preparation,... 

Caffeine Caffeine [l,3,7-trimethyl-l//-purine-2,6(3/7,7//)-dione], molecular formula C8H10N4O2, is a xanthine (purine) alkaloid, found mainly in tea leaves Camellia sinensis) and coffee beans (Coffea arabica). Caffeine is sometimes called guaranine when found in guarana (Paullinia cupana), mateine when found in mate (Ilex paraguariensis) and theine when found in tea. Caffeine is found in a number of other plants, where it acts as a natural pesticide. It is odourless white needles or powder. Apart from its presence in the tea and coffee that we drink regularly, caffeine is also an ingredient of a number of soft drinks. 

Other herbal stimulants include guarana or kola, which are natural sources of caffeine, just like the coffee bean. There are many such concoctions of caffeine or ephedra on the market, or recently taken off the market (Table 5.2). 

Caffeine is a naturally occurring substance found in the leaves, seeds, or fruits of more than 60 plants. These include coffee and cocoa beans, kola nuts, tea leaves, guarana (Paulinia cupana) and Paraguay tea. Thus it is present naturally in many beverages, such as coffee, tea, and cola drinks, or is added in small amounts (up to 200 ppm) in some soft drinks and in foods such as chocolate. Caffeine is obtained by solvent or supercritical fluid extraction from green coffee beans, mainly during the preparation of decaffeinated coffee. 

Extracts of coffee bean and cocoa bean have been produced experimentally that contained about 3% of caffeine and 3% theobromine respectively without the disadvantage of flavour concentration typically associated with those raw materials. These are potentially alternative natural sources of effective stimulants to guarana and kola. Other supplementary herbs that have a place in energy... 

Part of herb used The seeds, which are purple-brown to black with a characteristic white eye , contained within a red-orange fruit about the size of a hazelnut. Main actives Guarana has the highest known caffeine content of any herb at 3.6-5.8%. It also contains small amounts of theophylline and theobromine, the other stimulant purine alkaloids similar to caffeine. Besides these, guarana contains about 12% tannins and some saponins. 

Benefits The caffeine content makes guarana a strong central nervous system stimulant. It is traditionally used as a tonic for fatigue and to allay hunger and thirst. It also has short-term diuretic effects. The tannin content gives guarana an astringent effect and it has been used to treat diarrhoea. 

These products aim primarily to provide a boost to mental energy or buzz . They are marketed as pick-me-ups , and command a high profit margin. An impressive list of ingredients is essential for credibility and typical components include caffeine, taurine, glucuronolactone, inositol, maltodextrin, vitamins and herbal extracts such as guarana, ginseng and schizandra. 

The seeds of the Brazilian plant Paullinia cupana (Sapindaceae) are used to make a stimulant drink. Crushed seeds are mixed with water to a paste, which is then sun dried. Portions of this are then boiled with hot water to provide a refreshing drink. The principal constituent, previously called guaranine, has been shown to be identical to caffeine, and the seeds may contain 3-5%. Small amounts of theophylline (0-0.25%) and theobromine (0.02-0.06%) are also present. Guarana is widely available as tablets and capsules, or as extracts, in health food shops where it is promoted to relieve mental and physical fatigue. Labels on such products frequently show the active constituent to be guaranine, but may not indicate that this is actually caffeine. 

Baumann TW, Schulthess BH and Hanni K (1995) Guarana (Paullinia cupana) rewards seed dispersers without intoxicating them by caffeine. Phytochemistry 39, 1063-1070. 

Guarana contains tannins and has been used to treat diarrhea. It also contains a high concentration of caffeine, which, in conjunction with the alkaloids theobromine and theophylline, gives guarana diuretic and stimulant properties. Guarana is used to treat fatigue, mild depression, headache, and migraine. 

The purine nucleus is constructed by a condensation of the pyrimidine and imidazole (glyoxaline) nuclei (Figure 11.12). Xanthine is 2,6-dioxypurine caffeine, 1,3,7-trimethylxanthine theophylline, 1,3-dimethylxanthine and theobromine, 3,7-dimethylxanthine. These alkaloids are found in coffee, tea, cacao, kola, mate, and guarana (Figure 11.13). 

Methyl derivatives of xanthine (2,3-dioxypurine) namely caffeine (1,3,7-trimethyl-xanthine), theobromine (3,7-dimethylxanthine) and theophylline (1,3-dimethylxanthine) (Section 1, Appendix) are variously found in plants used for stimulatory drinks such as Ilex paraguayensis (mate) (Aquifoliaceae), Coffea species (coffee) (Rubiaceae), Paullinia cupana (guarana) (Sapindaceae), Cola acuminata (cola) and Theabroma cacao (cocoa) (Sterculiaceae) and Camellia sinensis (tea) (Theaceae). These methylxanthines are variously active as inhibitors of... 

Caffeine is one of most widely consumed alkaloids on a daily basis. As well as being a significant constituent of coffee (Caffea arabica) and tea Camellia sinensis), caffeine is also present in kola Kola species), guarana... 

---