Xanthine (/ ˈzænθiːn / or / ˈzænθaɪn /; archaically xanthic acid; systematic name 3,7-dihydropurine-2,6-dione) is a purine base found in most human body tissues and fluids, as well as in other organisms. Several stimulants are derived from xanthine, including caffeine, theophylline
Theophylline
Theophylline is used to treat lung diseases such as asthma and COPD. It must be used regularly to prevent wheezing and shortness of breath.
Theobromine
Theobromine, formerly known as xantheose, is a bitter alkaloid of the cacao plant, with the chemical formula C₇H₈N₄O₂. It is found in chocolate, as well as in a number of other foods, including the leaves of the tea plant, and the kola nut. It is classified as a xanthine alkaloid, others of which include theo…
What is xanthine?
This chemical is a purine, which is found in many foods. Xanthines are found in certain foods that some people have difficulty processing. The condition known as Xanthinuria can lead to too much xanthine being present in the body. As a result, sufferers are at dramatically increased risk of developing kidney stones, gout and muscle disease.
What foods and beverages contain xanthine?
Xanthine is found in coffee, tea and cola drinks as well as substances like caffeine, theobromine and theophylline. Caffeine is found in chocolate and cocoa, while theobromine is present in cocoa, tea and foods containing these things. Theophylline is present in all of the above foods and beverages.
What are some examples of xanthine alkaloids?
These are obviously consumed in considerable quantity around the world. Caffeine is the most important xanthine alkaloid. It is a mildly stimulant drug found in tea, coffee, cocoa, and the kola nut and is usually associated with the alkaloids theophylline and theobromine, which are mild cardiac stimulants.
Which of the following stimulants is derived from xanthine?
Several stimulants are derived from xanthine, including caffeine, theophylline, and theobromine. Xanthine is a product on the pathway of purine degradation. It is created from guanine by guanine deaminase. It is created from hypoxanthine by xanthine oxidoreductase. It is also created from xanthosine by purine nucleoside phosphorylase.
What foods have xanthines in them?
Occurrence. The xanthine alkaloids include caffeine, theobromine, and theophylline, and are well-known components of tea (Camellia sinensis), coffee (Coffea arabica), cola ingredients (Cola spp.), and cocoa (Theobroma cacao). These are obviously consumed in considerable quantity around the world.
What do xanthines do to the body?
Xanthines also stimulate muscle and cardiac cells and neurons. Xanthines can cause a mild diuresis. The xanthines have many minor side effects (anxiety, nervousness, tremor, headache, dizziness) but are largely well tolerated in the doses used to treat asthma and chronic bronchitis.
Is xanthine found in DNA?
Hypoxanthine and xanthine are not present in DNA or RNA but are important intermediates in the synthesis and degradation of purine nucleotides.
Is coffee a xanthine?
Caffeine, theobromine, and theophylline (Figure 1) belong to a group of compounds known as the xanthines. Caffeine (1,3,7-trimethylxanthine) and theobromine (3,7- dimethylxanthine) (1) are in such beverages as coffee, teas and colas and are common to the urine of these drinkers (2).
What kind of drugs are xanthines?
Xanthine derivatives are a group of alkaloids that work as mild stimulants and bronchodilators. Xanthine derivatives ease symptoms of bronchospasm and make breathing easier by relaxing the smooth muscles of the respiratory tract and reducing the airway's hypersensitive response to stimuli.
How is xanthine formed?
Xanthine oxidase is a form of xanthine oxidoreductase, an enzyme that generates reactive oxygen species such as superoxide radicals and hydrogen peroxide when it catalyzes the oxidation of hypoxanthine to xanthine, and can further catalyze the oxidation of xanthine to uric acid.
Which purine base is found in RNA?
guanineThe most important biological substituted purines are adenine and guanine, which are the major purine bases found in RNA and DNA.
Is caffeine a drug?
Summary. Caffeine is a drug that stimulates (increases the activity of) your brain and nervous system. Caffeine is found in many drinks such as coffee, tea, soft drinks and energy drinks. Chocolate also contains caffeine.
What is the function of xanthine oxidase?
The enzyme xanthine oxidoreductase (XOR) catalyzes the last two steps of purine catabolism in the highest uricotelic primates. XOR is an enzyme with dehydrogenase activity that, in mammals, may be converted into oxidase activity under a variety of pathophysiologic conditions.
What are the signs of xanthine toxicity?
Symptoms of overdose may include unusually fast or slow heartbeat, loss of appetite, nausea/vomiting, sleeplessness, irritability, restlessness, headache, increased thirst, fever, ringing in ears, delirium, muscle twitching or weakness, seizures, sweating, or fast breathing.
Is tea a drug?
Some types of tea contain caffeine, a psychoactive compound that many people consider addictive. It's speculated that regularly drinking tea may be linked with dependency-like symptoms in some people, but experts are still debating whether tea addiction can be considered a true addiction.
What are Xanthene beverages?
The Xanthines: Coffee, Cola, Cocoa, and Tea.
What is the mechanism of action of Xanthines in the nervous system?
The main mechanism of action of xanthine is represented by the inhibition of phosphodiesterase, enzyme that breaks a phosphodiester bond. The pharmacological activity of xanthine is expressed in smooth muscle, heart muscle, central nervous system and kidney.
What are the signs of xanthine toxicity?
Symptoms of overdose may include unusually fast or slow heartbeat, loss of appetite, nausea/vomiting, sleeplessness, irritability, restlessness, headache, increased thirst, fever, ringing in ears, delirium, muscle twitching or weakness, seizures, sweating, or fast breathing.
What is the function of xanthine oxidase?
The enzyme xanthine oxidoreductase (XOR) catalyzes the last two steps of purine catabolism in the highest uricotelic primates. XOR is an enzyme with dehydrogenase activity that, in mammals, may be converted into oxidase activity under a variety of pathophysiologic conditions.
How do xanthine oxidase inhibitors act?
Xanthine oxidase inhibitors reduce uric acid production by inhibiting the activity of xanthine oxidase, an enzyme that synthesizes uric acid from hypoxanthine, a purine derivative. Xanthine oxidase inhibitors specifically inhibit xanthine oxidase, without affecting the purines vital for DNA and RNA synthesis.
How to get rid of xanthine in kidneys?
Taking care to eat a low-purine diet can help keep xanthine out of the body. Fatty and xanthine-rich foods should be avoided, while eating plenty of carbohydrates may help the body process uric acid. Drinking lots of water is also important. Between 8 and 12 cups of clear fluids daily may reduce the chance of kidney stone formation.
What is the chemical that causes kidney stones?
This chemical is a purine, which is found in many foods. Xanthines are found in certain foods that some people have difficulty processing. The condition known as Xanthinuria can lead to too much xanthine being present in the body. As a result, sufferers are at dramatically increased risk of developing kidney stones, gout and muscle disease.
Can you eat coffee with xanthine?
Medications may be used to help treat symptoms, but doctors recommend avoiding foods that contain xanthines in the first place, as stated by MedicineNet. Xanthine is found in coffee, tea and cola drinks as well as substances like caffeine, theobromine and theophylline.
What is methylated xanthine?
The methylated xanthine compounds caffeine, theobromine, and theop hylline and their derivatives are used in medicine for their bronchodilator effects. (Dorland, 28th ed) A purine base found in most body tissues and fluids, certain plants, and some urinary calculi.
Is xanthine a tautomer?
9H-xanthine is an oxopurine in which the purine ring is substituted by oxo groups at positions 2 and 6 and N-9 is protonated. It has a role as a Saccharomyces cerevisiae metabolite. It is a tautomer of a 7 H-xanthine.
Is 9H xanthine a purine?
9H-xanthine is an oxopurine in which the purine ring is substituted by oxo groups at positions 2 and 6 and N-9 is protonated. It has a role as a Saccharomyces cerevisiae metabolite. It is a tautomer of a 7H-xanthine. A purine base found in most body tissues and fluids, certain plants, and some urinary calculi.
What is xanthine stone?
Xanthine is a type of purine , and xanthinuria is a genetic deficiency of xanthine oxidase, a defect in purine metabolism. Xanthine stones (purine stones) are seen in patients with severe hyperuricemia taking allopurinol, or in those with rare inherited forms of xanthinuria. 2,8-Dihydroxyadenine stones occur in patients with a deficiency of adenine phosphoribosyl transferase (APRT). Purine stones have poor response to usual treatments. Discontinuing allopurinol while feeding on a low-purine diet has dissolved xanthine stones. In general, treatment consists of surgical removal, urohydropropulsion (a nonsurgical, anesthetic procedure, where the bladder is filled with saline through a catheter, and the bladder is manually squeezed to force stones out through the urethra), or lithotripsy (uses high-energy soundwaves to break up the stones). Xanthine urolithiasis is usually a rare condition, easy to prevent or cure by forced hydration, appropriate alkalinization, and restriction of dietary purines. However, asymptomatic and undiagnosed stones may invade the kidney and urinary tract, resulting in destruction of parenchyma, nephrectomy, and renal failure.
What is xanthine oxido-reductase?
Xanthine oxido-reductase catalyzes the sequential hydroxylation of hypoxanthine to yield xanthine and uric acid. The enzyme can exist in two forms that differ primarily in their oxidizing substrate specificity. The dehydrogenase form preferentially utilizes NAD+ as an electron acceptor but is also able to donate electrons to molecular oxygen. By proteolytic breakdown as well as thiol oxidation xanthine dehydrogenase from mammalian sources can be converted to the oxidase form that readily donates electrons to molecular oxygen, thereby producing superoxide and hydrogen peroxide, but does not reduce NAD +. Compatible with an increase in the expression or activity of xanthine oxidase in early hypercholesterolemia, oxypurinol, an inhibitor of xanthine oxidoreductase, has been shown to reduce superoxide production and to improve endothelium-dependent vascular relaxations to acetylcholine in vessels from hyperlipidemic animals (33). The mechanisms underlying such a phenomenon remain unclear, however it has been demonstrated that certain cytokines can stimulate the expression of xanthine oxidase by the endothelium, or alternatively, that increased cholesterol levels may cause the release of xanthine oxidase (e.g. from the liver) into the circulation where it binds to endothelial glycosaminoglycans (34). The results of human studies concerning the efficacy of xanthine oxidase inhibition on endothelial dysfunction are somewhat contradictory. While Panza et al. (35,36) showed that endothelial dysfunction in hypercholesterolemic patients and hypertensive diabetics is improved by acute inhibition of xanthine oxidase with oxypurinol and allopurinol, other groups failed to show similar efficacy for allopurinol (37). Its role in mediating increased oxidative stress in the setting of hypertension is not quite clear. Oxypurinol has blood pressure-lowering effects comparable to heparin binding superoxide dismutase in spontaneously hypertensive rats (38), but fails to demonstrate a positive effect on endothelial dysfunction in hypertensive patients (35). More recent studies in patients with chronic congestive heart failure clearly failed to demonstrate any prognostic benefit when oxypurinol was added to conventional heart failure treatment (39).
How many XPT genes are there in the genome?
Four XPT genes are annotated in the complete genome of the Staphylococcus aureus subsp. aureus strain MRSA252 ( Holden et al., 2004) (GenBank accession code BX571856.1). The first XPT gene is annotated at position 441383..441961, as predicted by amino acid sequence similarity of the translated coding region ( E -value 1.5 × 10 −33, 53.403% id in 191 aa with B. halodurans XPT). The upstream region at position 441050..441153 is annotated as a putative XPT riboswitch, as predicted by Infernal (Rfam) with score 73.10. For the genomic region from 441033..441383,
What is the name of the mixture of theophylline and ethylenediamine?
Aminophylline is a combination mixture of theophylline and ethylenediamine (two amine groups connect by two carbons). It simply dissociates in the body to theophylline.
How long does it take for methylxanthines to increase FEV?
A Cochrane review in 2003 (4 studies, N 169 patients) found that the change in FEV 1 at 2 hours was similar in both groups but transiently increased with methylxanthines at 3 days (WMD 101 mL). Data on clinical outcomes were sparse. Trends toward improvements in hospitalization and length-of-stay were offset by a trend toward more relapses at 1 week. Changes in symptom scores were not significant. Methylxanthines caused more nausea and vomiting than placebo (OR 4.6) and trended toward more frequent tremor, palpitations, and arrhythmias.
Where are XPT genes annotated?
Four XPT genes are annotated in the complete genome of the Staphylococcus aureus subsp. aureus strain MRSA252 ( Holden et al., 2004) (GenBank accession code BX571856.1). The first XPT gene is annotated at position 441383..441961, as predicted by amino acid sequence similarity of the translated coding region ( E -value 1.5 × 10 −33, 53.403% id in 191 aa with B. halodurans XPT). The upstream region at position 441050..441153 is annotated as a putative XPT riboswitch, as predicted by Infernal (Rfam) with score 73.10. For the genomic region from 441033..441383,
Does xanthine dehydrogenase reduce NAD?
By proteolytic breakdown as well as thiol oxidation xanthine dehydrogenase from mammalian sources can be converted to the oxidase form that readily donates electrons to molecular oxygen, thereby producing superoxide and hydrogen peroxide, but does not reduce NAD +.
What is xanthine made of?
Xanthine is formed following enzymatic degradation of adenine and guanine. The term “xanthines” denotes a wide class of compounds whose central core (3,7-dihydro-purine-2,6-dione) is closely related to the DNA bases guanine and adenine (see Figures 1 and 2) 1). Like nucleobases, xanthines are capable of forming hydrogen bonds, allowing their insertion in duplexes 2) and guanine quadruplexes (G-quadruplexes) 3). Moreover, it has been shown that their self-association can give rise to four-stranded structures 4), which have attracted attention for applications in the field of molecular electronics 5). Moreover, methylxanthines are used as therapeutic agents acting, among others, as stimulants of the nervous system 6). The well-known caffeine, present in coffee and tea and various soft beverages, is none other than 1,3,7-trimethylxanthine (Figure 2). It is also worth noticing that 2′-deoxyxanthosine (dX) has been used in the extension of the genetic alphabet by purine pairing with a 2,4-diaminopyrimidine nucleoside, which has a hydrogen bonding pattern complementary to 2′-deoxyxanthosine (dX) 7).
What are the Xanthine medications?
The xanthines, caffeine and theobromine are the pharmacologically active components of a range of drinks such as coffee, tea, cocoa and soft drinks. Xanthines also include medicines such as theophylline, used in the treatment of asthma.
What is the best medicine for gout?
Xanthine oxidase inhibitor. Allopurinol and Febuxostat are xanthine oxidase inhibitor drugs that is used to treat gout and high levels of uric acid in the blood (hyperuricemia) caused by certain cancer medications, and kidney stones. Xanthine oxidase inhibitor works by causing less uric acid to be produced by the body.
What gene prevents xanthine dehydrogenase from turning on?
Mutations in the MOCOS gene prevent xanthine dehydrogenase and aldehyde oxidase from being turned on (activated). The loss of xanthine dehydrogenase activity prevents the conversion of xanthine to uric acid, leading to an accumulation of xanthine in the kidneys and other tissues.
What is xanthinuria in the kidneys?
Xanthine oxidase deficiency. Hereditary xanthinuria is a condition that most often affects the kidneys. It is characterized by high levels of a compound called xanthine and very low levels of another compound called uric acid in the blood and urine. The excess xanthine can accumulate in the kidneys and other tissues.
Does xanthine cause uric acid?
Because xanthine is not converted to uric acid, affected individuals have high levels of xanthine in their blood (hyperxanthinemia) and urine (xanthinuria) and very low levels of uric acid in their blood and urine. The excess xanthine can cause damage to the kidneys and other tissues.
Is xanthine a curative treatment?
There is no curative treatment for hereditary xanthinuria. The only recommended treatment for patients with xanthinuria is a low purine diet and high intake of fluids 11). Because the solubility of xanthine is relatively independent of urinary pH, urine alkalinization has no effect (in contrast to patients with uric acid lithiasis) 12). When kidney stones are present, a pyelolithotomy might be necessary.
How to detect xanthine?
The detection of xanthine was based on the catalytic conversion of xanthine to uric acid and hydrogen peroxide. Electrons released from the dissociation of hydrogen peroxide gave rise to a current. The biosensor showed a linear working range from 2 to 16 μM. The response time was 5 s and the limit of detection was 0.15 μM at 35°C and pH 7.0. Fish and meat samples spiked with known concentrations of xanthine were tested using the biosensor, and the results obtained were in good agreement with those obtained by the standard enzymatic colorimetric method. The biosensor successfully measured xanthine concentrations in fish, chicken, beef, and pork samples. The electrode retained 80% of its initial sensitivity after 180 uses over 60 days when stored dry at 4°C.
Which compound has the most chiral carbons?
The “most chiral” compounds (and percentage of their chiral carbons) are: kanamycin (83.3%), ( Fig. 2 ). aurothioglucose (83%), paromomycine (82.6%), pentosane-polysulfate-sodium (80%). The “most chiral” drug molecules, not surprisingly, are sugar-type compounds, produced by fermentation in “biological laboratories” of fungi or bacteria, clearly, under strictly chiral biochemical circumstances.
Is xanthine oxidase asymptomatic?
Cases with deficiency of only xanthine oxidase have also been reported (hereditary xanthinuria). Majority of patients however are asymptomatic, and in most of the cases the disease was diagnosed incidentally after discovery of low serum uric acid levels during examination of unrelated health problems. Owing to the apparently benign nature of xanthine oxidase deficiency, it may be concluded that the essentiality of molybdenum is ascribable to its participation in the activity of sulfite oxidase.
Where did xanthine come from?
…in 1776 from urinary calculi; xanthine was obtained from the same source in 1817. Xanthine also occurs in tea, as does caffeine, another purine compound. Guanine, found in guano, the accumulated excrement and dead bodies of birds, bats, and seals, and adenine were identified in 1891 as products of the…
What is a deficiency in xanthine oxidase?
…a deficiency in the enzyme xanthine oxidase. Normally this enzyme breaks down the purine base xanthine to uric acid, which is then excreted. In the absence of the enzyme, xanthine is not metabolized by the body and its concentration builds up in the blood and urine. Xanthinuria is not a…
