Showing papers on "Theobromine published in 2002"

Anodic Voltammetry of Xanthine, Theophylline, Theobromine and Caffeine at Conductive Diamond Electrodes and Its Analytical Application

Abstract: Boron-doped diamond (BDD) electrodes were used to examine the electrochemical oxidation of xanthine and its naturally occurring N-methyl derivatives, theophylline, theobromine and caffeine. Voltammetric studies showed that the mechanism of the overall reaction is similar to that of the oxidation of purine derivatives at the pyrolytic graphite electrode. The effects of pH, concentration and potential sweep rate on the voltammetric response were thoroughly investigated, and it was found that BDD exhibits excellent behavior, in terms of very well-defined, reproducible oxidation peaks, for xanthine, theophylline, theobromine and caffeine determination. The results enabled the measurement of the oxidation peak current to be used as the basis for a simple, accurate and rapid method for determining the investigated compounds, within a concentration range of 1 to 400 μM for theophylline, theobromine and caffeine, and of 1 to 100 μM for xanthine. Promising results were obtained for caffeine determination in real samples of commercially available products, without separation from the matrix.

Extraction of Methylxanthines from Guaraná Seeds, Maté Leaves, and Cocoa Beans Using Supercritical Carbon Dioxide and Ethanol

Abstract: New experimental data on the extraction of caffeine from guarana seeds and mate tea leaves, and theobromine from cocoa beans, with supercritical CO2 were obtained using a high-pressure extraction apparatus. The effect of the addition of ethanol to carbon dioxide on the extraction efficiency was also investigated. Caffeine extraction yields of 98% of the initial caffeine content in both wet ground guarana seeds and mate tea leaves were obtained. Extractions of caffeine from guarana seeds and mate tea leaves also exhibited a retrograde behavior for the two temperatures considered in this work. In the removal of theobromine from cocoa beans, a much smaller extraction yield was obtained with longer extraction periods and consequently larger solvent requirements. The results of this study confirm the higher selectivity of CO2 for caffeine in comparison with that for theobromine, and also the influence of other components in each particular natural product on the extraction of methylxanthines. The effect of the...

Effects of Coffee Components on the Response of GABAA Receptors Expressed in Xenopus Oocytes

Abstract: To study the effects of tea components on ionotropic gamma-aminobutyric acid (GABA) receptor response, ionotropic GABA receptors (GABA(A) receptors) were expressed in Xenopus oocytes by injecting cRNAs synthesized from cloned cDNAs of the alpha(1) and beta(1) subunits of the bovine receptors, and their electrical responses were measured by a voltage clamping method. Extracts of green tea, black tea, and oolong tea in an aqueous solution induced the GABA-elicited response, which showed that these teas contain GABA, whereas coffee does not. Caffeine weakly inhibited the response in a competitive manner (K(i) = 15 mM), and (+)-catechin inhibited it in a noncompetitive one (K(i) = 1.7 mM). Especially, two catechin derivatives, (-)-epicatechin gallate and (-)-epigallocatechin gallate, inhibited the response strongly. Alcohols such as leaf alcohol or linalool potentiated the response, possibly because their binding to the potentiation site enhances the GABA-binding affinity to GABA(A) receptors when they bind. Extracts of green tea made with ethyl ether, which must contain lipophilic components of green tea, inhibited the response elicited by GABA, possibly because the amounts of caffeine and catechin derivatives were much larger than fragrant alcohols in such extracts of tea.

Extraction of Caffeine, Theobromine, and Cocoa Butter from Brazilian Cocoa Beans Using Supercritical CO2 and Ethane

Abstract: Supercritical extraction using ethane and CO2, acceptable solvents for food products, was explored for the recovery of the methylxanthines caffeine and theobromine and cocoa butter from cocoa beans using a high-pressure apparatus. Continuous extraction of cocoa beans was performed at 343.2 K using CO2 at pressures of 20 and 40 MPa and ethane at pressures of 15.2, 24.8, and 28.3 MPa. The extraction yields of cocoa butter obtained with ethane were much higher than those obtained with CO2 because of the higher solubility of this fat in ethane. A pronounced effect of pressure on the extraction of methylxanthines and cocoa butter was observed for both solvents. Extraction curves revealed the greater facility of these solvents to extract cocoa butter followed by caffeine and theobromine. This behavior suggests a range of possible conditions under which the extraction and isolation of cocoa butter, caffeine, and theobromine from cocoa beans can be achieved. The methylxanthines in cocoa beans were slightly more s...

Optimized method for simultaneous determination of catechin, gallic acid, and methylxanthine compounds in chocolate using RP-HPLC

Abstract: The simultaneous determination of catechins, gallic acid, and three methylxanthine compounds was determined in chocolate extract by reversed-phase HPLC. An isocratic HPLC procedure using Hypersil-ODS column with methanol three distilled water–formic acid (48.75:200.5:0.75, v/v/v) as a mobile phase was used and the HPLC profiles of 11 chocolate products were obtained. (–)- Epicatechin, (–)-epigallocatechin gallate, levels were very high whereas (+)-catechin, (–)-epigallocatechin and (–)-epicatechin gallate were lower values. Gallic acid was predominant compounds with extremely high levels in all chocolate samples. The content of three methylxanthine, theobromine, theophylline and caffeine was quantified with this procedure. Caffein amounts were low in all samples, while theobromine levels were high in milk and dark chocolates. Theophylline was at trace levels in some chocolates and could not be detected in some samples. This method was reliable, reproducible and objective for quantitative identification of flavanols and alkaloid compounds in the chocolate industry.

Inheritance studies of caffeine and theobromine content of Mate ( Ilex paraguariensis ) in Misiones, Argentina

Abstract: In order to start a genetic improvement program for quality in the Mate crop (Ilex paraguariensis), it was attempted to estimate the actual genetic parameters of caffeine, theobromine and related quality traits, using available progeny tests in Misiones, Argentina Using cluster analysis, eight groups of similar characteristics could be identified, and individual within full-sib family selection for quality was performed Additive effects were strong for caffeine but weak for theobromine Co-heritability between caffeine and theobromine was positive, suggesting that additive genetic correlations and dominance correlations are concurring The strong influence of paternal progenitors regarding caffeine needs more research

Theobromine with an anti-carcinogenic activity

Abstract: Disclosed is theobromine with an anti-carcinogenic activity which inhibits the suppression of GJIC (gap junctional intercellular communication), a pathological phenomenon occurring during development of various kinds of cancers including liver cancer, as well as DNA synthesis of cancer cells thereby inhibiting proliferation of liver, gastric and colon cancer cells.

Secondary metabolites from the Gorgonian Echinomuraceae splendens (Thomson & Simson)

Abstract: Two xanthine derivatives, caffeine (1, 3, 7-trimethylxanthine) 1 and its 2-O-methyl analog (Δ 1 , O 2 - methyl theobromine) 2, N-methyl-pyrazole-5-carboxylic acid 3 and a tetrahydroxy sterol, 1β, 3β, 5α, 6β-tetrahydroxycholestane 4 have been isolated from the methanol extract of the gorgonian Echinomuraceae spendens (Thomson & Simson). These compounds have been purified on silica gel and Sephadex LH-20 columns and their structures elucidated by spectroscopic studies. This is the first report of the occurrence of compounds 2 and 3 in nature. Caffeine exhibits mild antifouling activity against marine fouling organisms while its O-methyl analog 2 is inactive.

The measurement of theophylline in human serum or plasma using gas chromatography and isotope dilution-mass spectrometry (GC-IDMS) taking other substituted xanthines into consideration.

Abstract: A method is described which uses a combination of gas chromatography and isotope dilution-mass spectrometry (GC-IDMS) to determine the concentration of theophylline (1,3-dimethyl xanthine) in human plasma or serum samples. The effects of similar substituted xanthines - namely theobromine (3,7-dimethyl xanthine), paraxanthine (1,7-dimethyl xanthine) 1,3-dimethyl-7-(2-hydroxyethyl) xanthine (internal standard HPLC) and caffeine (1,3,7-trimethyl xanthine) were tested to confirm the specificity of the method. The derivatisation of all xanthines was performed with N-methyl-N-trimethylsilyl trifluroacetamide (MSTFA). The internal standard used was 2-(13)C ,1,3-(15)N2-theophylline. The extraction and derivatisation procedures were examined in detail and optimised stepwise during the development of the method. High-performance liquid chromatography (HPLC) was used for comparison.

Use of a food additive comprising theobromine for the prevention of colon, gastric or liver cancer

Abstract: Disclosed is theobromine with an anti-carcinogenic activity which inhibits the suppression of GJIC (gap junctional intercellular communication), a pathological phenomenon occurring during development of various kinds of cancers including liver cancer, as well as DNA synthesis of cancer cells thereby inhibiting proliferation of liver, gastric and colon cancer cells.

Cupua seed-origin fat, process for producing the same and use thereof

Abstract: Cupua fat originating in cupua seeds which is free from any excitants such as caffeine or theobromine and contributes to good health and health foods such as chocolate produced by using the same.

Chapter 51 – Theophylline

Abstract: Publisher Summary This chapter highlights the role of theophylline in the treatment of airway diseases and discusses the future of theophylline as implicated in asthma and chronic obstructive pulmonary disease (COPD) management. Theophylline is a methylxanthine similar in structure to the common dietary xanthines, caffeine, and theobromine. Theophylline is one of the most widely prescribed drugs for the treatment of airway diseases because it is inexpensive. However, the frequency of side effects and the relatively low efficacy of theophylline have led to its reduced usage as inhaled β2-agonists are much more effective as bronchodilators and inhaled corticosteroids have a greater anti-inflammatory effect. Recent studies suggest that theophylline can have an anti-inflammatory and immunomodulatory effect, when given in low doses. At these low doses, the drug becomes easier to use, side effects are uncommon, and the problems of drug interaction are decreased, thus making the clinical use of theophylline less complicated. In the context of asthma, theophylline exhibits synergistic interaction with the anti-inflammatory mechanism of corticosteroids, and as slow-release theophylline preparations are cheaper than long-acting inhaled β2-agonists and antileukotrienes, it becomes a logical choice to use low-dose theophylline as an add-on therapy for asthma control. Selective phosphodiesterase (PDE) inhibitors are also considered for reducing the adverse effects of theophylline.