General Description
Odorless white powder or white glistening needles, usually melted together. Bitter taste. Solutions in water are neutral to litmus. Odorless.
Reactivity Profile
CAFFEINE(58-08-2) may be hygroscopic. Aqueous solutions (1.12 mg/mL) are stable for three weeks at 41° F if protected from light. In normal room lighting and at room temperature, solutions are stable for 3 days. Solutions of this chemical in water, DMSO, 95% ethanol or acetone should be stable for 24 hours under normal lab conditions. REACTIVITY: This compound may react with strong oxidizing agents. CAFFEINE(58-08-2) is also incompatible with iodine, silver salts and tannins. This compound is a very weak base. CAFFEINE(58-08-2) is decomposed by strong solutions of caustic alkalis.
Air & Water Reactions
Efflorescent in air. Water soluble.
Hazard
One grain or more is toxic, 200 μg/m L has
been found to inhibit activity of the enzyme DNA
polymerase. Use in soft drinks not to exceed 0.02%.
Questionable carcinogen.
Fire Hazard
Flash point data for this chemical are not available; however, CAFFEINE is probably combustible.
Description
Caffeine is a purine alkaloid commonly found in coffee and tea. Several in vivo studies have demonstrated that topical and oral administration of caffeine exerts a photoprotective effect
through various mechanisms. Specifically, caffeine has been demonstrated to induce apoptosis in DNA damaged epidermal cells and tumors while sparing normal tissue. Mouse models demonstrate that this
apoptotic effect is secondary to increased expression of wild-type p53, a tumor suppressor gene that is
commonly mutated in UV-related skin cancers. Moreover, caffeine also has a sunscreen-like effect
and inhibits formation of UVB-induced thymine dimers and sunburn skin lesions.
Description
Caffeine is an alkaloid purine belonging to the group of organic compounds called methylxanthines. Pure caffeine is a white, crystalline, bitter-tasting compound. Caffeine is found in a number of plants, principally coffee and tea plants, as well as cola and cacao nuts. In plants, caffeine functions as a natural pesticide to deter insects.
Chemical Properties
Caffeine is the alkaloid 1,3,7-trimethylxanthine. It is one of the xanthine derivatives present up to 1.5% in seeds of
coffee (Coffea arabica L.) and up to 5% in the leaves of tea (Camelia sinensis). It is a component of the beverages made from these
plants. Caffeine is also a component of chocolate (Theobroma cacao) and the cola nut (Cola acuminata Schott and Endel. and related
species), the extract of which is used in cola drinks. It is virtually odorless. Caffeine is added to cola-type beverages for its enhancement
of flavor. Subtle and subliminal flavors are widely appreciated by consumers and caffeine has a modifying effect on other components
of the beverage. The threshold for detecting the presence of caffeine in liquid foods varies depending on the nature of other
substances present, but lies close to the level characteristic of currently produced cola-type beverages. The threshold for detection of
caffeine in water has been shown to be 0.0095%; in liquid foods, 0.0184%. In one study, panelists could distinguish a solution containing
0.0058% caffeine from the control. The threshold for detecting taste difference between an aqueous solution of caffeine and
a water control was also shown to be 0.005% caffeine and to distinguish bitterness, 0.011% caffeine. In aqueous solutions containing
threshold and subthreshold concentrations of caffeine, sucrose, citric acid and salt, all compounds depressed the taste intensity of
each other.*
Chemical Properties
white to light yellow crystal powder
Physical properties
Appearance: odorless silky needle-like crystal or crystal powder with the color of
white or a little yellowish green. Solubility: weathering, easily dissolved in water or
chloroform and slightly soluble in water, ethanol, or acetone, very slightly dissolved
in ether. Melting point: 235–238?°C.
Originator
Caffedrine,Thompson Med.
Occurrence
Reported found in coffee and guarana.
History
Runge isolated caff eine from coffee in 1819. Caffeine derives its name from the Kaffa region of Ethiopia. Caffeine comes from the German kaffeine, which in turn is derived from the German word for coffee, kaffee. In 1827, a compound isolated from tea was named theine, but this was eventually shown to be caffeine.
Definition
ChEBI: A trimethylxanthine in which the three methyl groups are located at positions 1, 3, and 7. A purine alkaloid that occurs naturally in tea and coffee.
Indications
This product is included in the Pharmacopoeia of the People’s Republic of China
(2015), the British Pharmacopoeia (2017), the United States Pharmacopeia (40), the
Japanese Pharmacopoeia (17th ed.), the European Pharmacopoeia (9.0th ed.), the
Indian Pharmacopoeia (2010), and the International Pharmacopoeia (5th ed.).
Commonly used dosage forms of caffeine include tablet, powder, and injection.
Mainly used dosage forms in the market include caffeine citrate tablets, amidopyrine caffeine tablets, amidopyrine caffeine, children acetaminophen aspirin caffeine
tablets, ergotamine caffeine tablets, caffeine sodium benzoate injection, cafe bromine agent, etc.
Manufacturing Process
Caffeine was synthesized by the reaction N-chloromethylation of theophylline
by action dimethylsulphate in dimethylsulfoxide.
Brand name
NoDoz Caplets and
Chewable Tablets (Bristol-Myers Products).
Therapeutic Function
Neurotropic, Central stimulant
Aroma threshold values
Detection at 29 to 300 ppm. Also see description.
Taste threshold values
See Description.
Health Hazard
Caffeine is a stimulant of the central nervoussystem. It eliminates fatigue and drowsiness. However, high doses cause gastrointestinal motility, restlessness, sleeplessness,nervousness, and tremor. Acute poisoningeffects include nausea, vomiting, headache,excitability, tremor, and sometimes, convulsive coma. Other symptoms may be respiratory depression, muscle contraction, distortedperception, and hallucination. Ingestion of15–20 g may be fatal to humans.
LD50 value, oral (mice): 127 mg/kg
LD50 value, oral (rabbits): 224 mg/kg
Animal studies indicate that caffeine athigh doses produces adverse reproductiveeffects, causing developmental abnormalities. It tested negative in the histidine reversion–Ames and TRP reversion tests.
Biological Activity
Central nervous system stimulant. Antagonist at A 1 and A 2A adenosine receptors and inhibitor of cyclic nucleotide phosphodiesterases. Mobilises calcium from intracellular stores and inhibits benzodiazepine binding to GABA receptors.
Clinical Use
The commonly used clinical preparations include caffeine sodium benzoate and
ergotamine caffeine. The preparation of caffeine sodium benzoate (injection) is constituted of 0.12?g/ml of caffeine, 0.13?g/ml of sodium benzoate, and cafe bromine
mixture (oral liquid). Clinically, it can be used for migraine headaches, cerebral artery dilated headache, or headache caused by histamine. However,
it is invalid in the prevention of headaches. The adverse reactions include nausea,
vomiting, abdominal pain, and fatigue. Other common symptoms include numbness
and tingling of the hands, toes, and face and swelling of the foot and lower limb.
Overdose causes severe poisoning, mental disorder, ataxia, convulsions, gray chills
of the hand and foot, sensory disturbance, and even death due to coma and respiratory paralysis. Caffeine citrate preparation, including injection and oral solution,
is the only internationally approved drug for the treatment of premature infant
apnea.
Synthesis
Usually obtained from tea dust in which it is present up to 5% or as a by-product from the manufacture of caffeine-free
coffee; synthetically prepared starting with dimethylurea and malonic acid.
target
Estrogen receptor | GLUT | Progestogen receptor
Environmental Fate
Caffeine can have profound effects on the cardiovascular
system. At least four mechanisms have been proposed for the
pro-arrhythmic potential of caffeine in overdose. First,
caffeine increases circulating catecholamines. Second, caffeine
inhibits phosphodiesterase. Increased circulating catecholamines
after caffeine overdose increase b1-receptor stimulation.
Stimulation of b1-receptors increases intracellular cAMP
by G protein stimulation of adenylate cyclase. The activity of
cAMP is prolonged due to its decreased metabolism as
phosphodiesterase is inhibited by caffeine. Subsequently,
b1-receptor effects are exaggerated and tachydysrhythmias are
induced. Third, caffeine increases myocardial intracellular calcium. Caffeine both induces release of calcium from the
sarcoplasmic reticulumand blocks calcium’s reuptake into the
sarcoplasmic reticulum. This resulting increase in cytosolic
calcium may provoke dysrhythmias. Fourth, caffeine blocks
cardiac adenosine receptors, which have been shown to be
antiarrhythmic.
The hypotension that has been noted with overdoses of
caffeine is due primarily to two mechanisms. First, caffeineinduced
tachydysrhythmias lead to inadequate filling of the
heart and subsequent decrease in cardiac output. Second,
caffeine augments β2-effects and causes subsequent vasodilation
with resulting hypotension.
Purification Methods
Caffeine crystallises from water or absolute EtOH. [Beilstein 26 III/IV 2338.]
Toxicity evaluation
Caffeine’s production and widespread use as an additive to
food and as a stimulant may result in release to the environment
through waste systems. It has an estimated vapor pressure
of 7.3×10-9 mmHg (25°C), which indicates that it will exist as particulate in the atmosphere. Caffeine is not susceptible to
photolysis and if released into soil it has a high mobility based
on the Koc of 22.
