Caffeine pka

Medically reviewed by Drugs. Last updated on Nov 1, Acetaminophen has been associated with cases of acute liver failure, at times resulting in liver transplant and death.

Most of the cases of liver injury are associated with the use of acetaminophen at doses that exceed milligrams per day, and often involve more than one acetaminophen containing product. Butalbital 5-allylisobutylbarbituric acidis a short to intermediate-acting barbiturate. It has the following structural formula:. Caffeine 1,3,7-trimethylxanthineis a central nervous system stimulant. It consists of a fixed combination of butalbital, acetaminophen, and caffeine.

The role each component plays in the relief of the complex of symptoms known as tension headache is incompletely understood.

Butalbital is well absorbed from the gastrointestinal tract and is expected to distribute to most tissues in the body. Barbiturates in general may appear in breast milk and readily cross the placental barrier. They are bound to plasma and tissue proteins to a varying degree and binding increases directly as a function of lipid solubility. The plasma half-life is about 35 hours. Urinary excretion products include parent drug about 3.

The plasma-to-blood concentration ratio was almost unity, indicating that there is no preferential distribution of butalbital into either plasma or blood cells.

Acetaminophen is rapidly absorbed from the gastrointestinal tract and is distributed throughout most body tissues. The plasma half-life is 1. Elimination of acetaminophen is principally by liver metabolism conjugation and subsequent renal excretion of metabolites. Like most xanthines, caffeine is rapidly absorbed and distributed in all body tissues and fluids, including the CNS, fetal tissues, and breast milk.

Caffeine is cleared through metabolism and excretion in the urine. The plasma half-life is about 3 hours. Hepatic biotransformation prior to excretion results in about equal amounts of 1-methylxanthine and 1-methyluric acid. Butalbital, acetaminophen, and caffeine tablets, USP are indicated for the relief of the symptom complex of tension or muscle contraction headache.By coffee and tea being a really important part of our society, I thought the information about its basic — and most important — component should be easily available on the internet.

Well, think again. Besides same basic descriptions and parameters in Wikipedia where elsethere were surprisingly few information available. Therefore I compiled some data on caffeine solubility, content in coffee beans and extraction efficacy from coffee beans to serve as a background reading for my previous posts. And to serve me as a reference for all my future research. Water solubility of caffeine is really high and is usually not an issue when preparing your caffeinated drink.

It is, as almost all solubilities, temperature dependant. Sadly, it is not that easy to get the solubility data on the internet — wikipedia lists solubility at three different temperatures while further search adds two additional temperatures and their corresponding solubilities. The results are listed in the table and graph below. As usual for the solubility, the caffeine solubility curve is exponential. The equation is presented on the graph, so one can calculate approximate solubility at any given temperature.

The calculated value is obviously only an approximation, but fairly good one in my opinion. Water solubility of caffeine is of course the main solubility that is interesting, but solubility in other solvents might also prove useful. If you are making ethanolic coffee preparations or just want to do some caffeine extraction, than you should look into that.

The table below is a list of some solvents and corresponding solubility at given temperature. Caffeine content in coffee beans can, as any material coming from nature, vary depending on many factors.

The main difference is the plant source of the beans — beans originating from arabica Coffea arabica have around half of the caffeine content than those coming from robusta Coffea robusta or Coffea canephora. Besides this, time of the year, ripnes of beans when pickedweather conditionsgeographic location and so on can also have a significant effect on caffeine content.

Well, the standard reference — Wikipedia — puts caffeine content of arabica between 0. The source is International coffee organization, although the link from Wikipedia reference points at empty location. Other Wikipedia resource claims 2.

caffeine pka

The values are not an exact match, again confirming variability in the caffeine content. Some further research yielded the list of data from scientific literature, which is shown below, together with the sources.

The variations for arabica are from 0. One can see there is great variability and that the values can differ around twofold. One can use the averages for mixes of coffee bought in retail stores, which by blending even out the variations.

Butalbital, Acetaminophen and Caffeine

Speciality coffee, coming from single region and single produces can, however, have greater variability. Not just the amount of caffeine and the caffeine solubility in water will determine caffeine content in your coffee.

The speed with which the caffeine goes into water is also crucial. To put in simpler terms — if the caffeine goes slowly from the beans into the coffee, there might not be enough time for all the caffeine to be extracted during a short preparation time.

The speed is dependant upon many facts like size of coffee grains, difference in amount of caffeine in grains and in water, temperature, time of extraction and if the whole thing is mixed or not i.

Since the caffeine solubility in water is really high, probably all the caffeine is extracted from the beans i. Scientific literature is confirming my reasoning here and here. Particle size has a great influence on the speed with which the caffeine is extracted — the smaller the particles, faster the extraction — while mixing did not have an influence at a given particle size.By born2diveFebruary 10 in Chemistry.

Ok if i understand my chemistry correct a hydroxide has a pKa value of Next question if caffeine can form caffeine citrate, what is preventing caffeine from forming caffeine phosphate??? Now my investigation shows that caffeine is a base and has a pKa value of 14?

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Caffeine Inhibits Cell Proliferation and Regulates PKA/GSK3β Pathways in U87MG Human Glioma Cells

You can adjust your cookie settingsotherwise we'll assume you're okay to continue. Chemistry Search In. Pka value caffeine citrate caffeine phosphate soft drinks?

Recommended Posts. Posted February Please let me know. Share this post Link to post Share on other sites. I'm fairly sure that caffeine citrate is not a salt. I think it's a hydrogen bonded molecular complex.

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caffeine pka

Sign in Already have an account? Sign In Now. Go To Topic Listing. Sign In Sign Up.Caffeine is the most commonly ingested methylxanthine and has anti-cancer effects in several types of cancer. In this study, we examined the anti-cancer effects of caffeine on gliomas, both in vitro and in vivo. In vivocaffeine- treated tumors exhibited reduced proliferation and increased apoptosis compared with vehicle-treated tumors. These results suggest that caffeine induces cell cycle arrest and caspase-dependent cell death in glioma cells, supporting its potential use in chemotherapeutic options for malignant gliomas.

Gliomas are the most common primary tumors arising within the brain Nakada et al. Although surgery followed by chemotherapy is the normal treatment regimen for gliomas, most malignant gliomas are resistant to chemotherapeutic agents. Because the blood-brain barrier BBB restricts and regulates the delivery of chemotherapy agents, the prognosis for glioma is poor Stupp et al.

Therefore, it is necessary to develop highly permeable agents that cross the BBB for the chemotherapeutic treatment of patients with malignant glioma. Caffeine 1,3,7-methylxanthine is a common component of many popular drinks, such as tea, coffee, and soft drinks Fredholm et al. Caffeine has a diverse range of pharmacological effects. It inhibits phosphodiesterase activity, alters intracellular calcium levels, inhibits phosphatidylinositol kinase PI3K activity, antagonizes adenosine receptors, increases levels of cAMP, and activates cAMP-dependent protein kinase PKA Daly and Fredholm, ; Fredholm et al.

Recently, many studies reported that caffeine has anti-cancer effects through the induction of apoptosis and suppression of cell proliferation Bode and Dong, in several cancer types, including neuroblastoma Jang et al.

Caffeine has also been reported to induce pindependent G1- phase arrest in lung adenocarcinoma cell lines Qi et al. Additionally, caffeine has been shown to inhibit epidermal growth factor EGF -induced cell transformation in the JB6 mouse epidermal cell line Nomura et al.

Although an inverse association was recently reported between caffeine and glioma risk Holick et al. Considering that caffeine penetrates the BBB and exerts multiple effects at a cellular level on the central nervous system CNS Fredholm et al. To investigate this hypothesis, we evaluated the anti-cancer effects of caffeine in vitro and in vivo using the glioma cell line, U87MG.

The effects of caffeine on human glioma cell growth were determined using the MTT colorimetric assay. After caffeine treatment, BrdU was added to the medium 4 h before the termination of the experiment. BrdU incorporation into cells was determined by anti-BrdU antibody immunostaining, and absorbance was measured at dual wavelengths of and nm.

Ten thousand events were recorded for each sample. At the end points of the colony formation assays, cells were fixed, stained with crystal violet, and photographed.

Cells were lysed in lysis buffer [50 mM Tris-Cl pH 8. Protein concentrations were determined using a bicinchoninic acid protein assay kit Pierce Biotechnology, Inc. Equal amounts of protein were resolved by sodium dodecyl sulfate polyacrylamide gel electrophoresis and transferred to nitrocellulose membranes. The control animals were given distilled water. Immunohistochemistry was performed on tumor tissues using the indicated antibody.

Apoptotic cells were quantitatively determined using the terminal deoxynucleotidyl transferase-mediated deoxyuridine triphosphate nick end-labeling TUNEL assay. A P value of less than 0. To investigate the potential anti-cancer effects of caffeine on glioma, we used the U87MG glioma cell line. Exponentially growing cells were treated with increasing doses of caffeine, and cell viability was assessed.By using our site, you acknowledge that you have read and understand our Cookie PolicyPrivacy Policyand our Terms of Service.

Chemistry Stack Exchange is a question and answer site for scientists, academics, teachers, and students in the field of chemistry. It only takes a minute to sign up. I am looking to add caffeine powder in pure form to water that has a pH level of 7 or higher.

What would the pH level be if I do this? Is Caffeine itself acidic? Caffeine is not acidic. In fact, it is basic. It will raise the pH of water to some degree.

It is a weak base, so the free base will exist in equilibrium with its protonated counterpart. Due to its basicity, it will be more soluble in low pH aqueous solutions than in high pH solutions. This is because in low pH solutions, caffeine would exist completely as a protonated salt, making it more hydrophilic. Despite this, caffeine is very polar and is still quite soluble in water at higher pH levels. The six-membered pyrimidinedione can exist in an aromatic, zwitterionic form where both amide nitrogens have formed double bonds to respective adjacent carbonyls.

This six-membered ring had been observed as being planar. Therefore, it has been concluded that caffeine does indeed exist primarily as its zwitterionic resonance form, with two positive charges and two negative charges. The negative charges exist on the two carbonyl oxygens. These may be slightly basic, too, but significantly less so than a structurally similar hydroxyphenol e. Therefore, the basic imidazole nitrogen likely has largest effect on the pH.

The fact that there is possibly more that one weakly basic atom on the caffeine molecule complicates calculations as far as determining a theoretical pH. Also, the calculation would require the quantity of caffeine you will add.

If you need an exact number, you will have to measure it. You can be sure, however, that the pH of the water will rise as caffeine is added. Caffeine 1,3,7 trimethylxanthine is not acidic by itself in its freebase form it is an alkaloid which behaves as a base, although it can be ionic or non-ionic.

Caffeine solubility, content in coffee beans and extraction

Resonance or mesomerism allow resonance structures to form due to delocalized electrons within the compound, because of this caffeine can be a zwitterion. Use a ph indicator to determine the pH before and after the addition of the caffeine and analyze the change in pH. Sign up to join this community.

The best answers are voted up and rise to the top. Home Questions Tags Users Unanswered. Caffeine dissolution Ask Question. Asked 4 years, 6 months ago. Active 4 years, 3 months ago. Viewed 14k times. Mithoron 4, 8 8 gold badges 32 32 silver badges 49 49 bronze badges. Copp C. Copp 41 1 1 gold badge 1 1 silver badge 3 3 bronze badges.Dishing out the latest medical research from an athlete's perspective.

Caffeine, packed into the gel packs to the right, boosts athletic performance by regulating glucose-related metabolic pathways. If you are an endurance athlete you have probably taken caffeine before a competition. Many studies have shown that caffeine boosts both maximum speed and endurance.

The question that will be addressed here is how caffeine boosts performance from a biological stand point. So to understand how caffeine works, a basic understanding of the regulation of cellular respiration, glycogen metabolism and fatty acid metabolism are necessary. PKA targets 6 different enzymes in our metabolism.

PKA blocks fatty acid biosynthesis, the synthesis of fat from the glucose derivative acetyl CoA. Fatty acid oxidation, the breakdown of fatty acids to energy in the form of free fatty acids which are exported to muscle cells is inhibited by fatty acid biosynthesis. This prevents fatty acid biosynthesis and fatty acid oxidation from occurring in a cell simultaneously.

Therefore, PKA essentially activates fatty acid oxidation by inhibiting fatty acid biosynthesis. With higher free fatty acid concentration in the blood, muscle cells have an easier time grabbing them and using them for energy.

In the liver, PKA activates glycogen breakdown to glucose and inhibits glycogen synthesis. This increases blood glucose levels allowing muscle cells to grab more glucose. The liver also releases more glucose because the breakdown of amino acids to glucose is activated by PKA. Caffeine does not directly regulate PKA levels.

There are several steps, in fact, to get from caffeine to increased levels of PKA. Caffeine inhibits cyclic nucleotide phosphodiesterase, an inhibitor of cyclic AMP. Thus, because caffeine knocks out the inhibitor of cyclic AMP, caffeine raises cyclic AMP levels via cyclic nucleotide phosphodiesterase. In summary, caffeine inhibits cyclic nucleotide phosphodiesterase which in turn causes cAMP activity to rise causing PKA levels to rise.

Caffeine elicits a similar response in the liver, adipocytes and muscle cells as the hormone glucagon activated by low-blood glucose and the fear-response hormone adrenaline.

caffeine pka

Caffeine boosts athletic performance because it increases the muscle's quick energy supply. If caffeine is in the body for an hour before the athletic performance, the muscle spends that hour building its energy reserves so that it is available for expenditure during competition.

Exercise Medicine Dishing out the latest medical research from an athlete's perspective. Sidebar [Skip] Welcome to Exercisemed. Why Caffeine Boosts Performance Caffeine, packed into the gel packs to the right, boosts athletic performance by regulating glucose-related metabolic pathways. Structure of Caffeine. All rights reserved.Always consult your healthcare provider to ensure the information displayed on this page applies to your personal circumstances. The easiest way to lookup drug information, identify pills, check interactions and set up your own personal medication records.

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Skip to Content. Pain treatment Pain, arthritic, mild treatment or Fever treatment —Acetaminophen and salicylate combinations are indicated to relieve mild to moderate pain and reduce fever.

Salicylamide is less effective than acetaminophen or aspirin. These medications provide only symptomatic relief; additional therapy to treat the cause of the pain or fever should be instituted when necessary. Although acetaminophen may be effective in relieving pain caused by mild osteoarthritis, it has minimal anti-inflammatory activity.

Salicylamide also has minimal anti-inflammatory activity. Therefore, efficacy in relieving pain caused by inflammation or arthritis may depend upon the quantity of aspirin present in the individual product. Achieving and maintaining therapeutically effective salicylate plasma concentrations may require ingestion of undesirably large daily doses of other ingredients present in these formulations.

Also, prolonged high-dose administration of these combinations is not recommended because of the risk of analgesic nephropathy. Acetaminophen and salicylates may act by inhibiting prostaglandin synthesis in the central nervous system CNS and through a peripheral action by blocking pain-impulse generation.

The peripheral action may also be due to inhibition of the synthesis of prostaglandins or to inhibition of the synthesis or actions of other substances that sensitize pain receptors to mechanical or chemical stimulation.

Acetaminophen and Salicylates (Systemic)

Acetaminophen may act predominantly in the CNS, whereas salicylates may act predominantly via peripheral actions. Caffeine: A mild CNS stimulant. The U. FDA has determined that studies have shown that caffeine is an effective adjuvant to aspirin, but that studies performed to date have failed to demonstrate that it is an effective adjuvant to acetaminophen. The central action may involve inhibition of prostaglandin synthesis in the hypothalamus.

However, there is some evidence that salicylates may also act through other mechanisms to relieve fevers caused by endogenous pyrogens that do not act via a prostaglandin mechanism.


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