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Theobromine

About: Theobromine is a research topic. Over the lifetime, 1137 publications have been published within this topic receiving 29723 citations. The topic is also known as: 3,7-Dimethylxanthine & Theobromin.


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Journal ArticleDOI
TL;DR: It is suggested that caffeine and trimethadione metabolism in healthy subjects is mediated by only in part by a form(s) of P450 enzymes involved.
Abstract: Pharmacokinetic interactions between caffeine 2 mg/kg and trimethadione 4 mg/kg were evaluated in 10 healthy volunteers. Whether administered alone or together, the total body clearance (CL), the apparent volume of distribution (Vd) and half-life (t1/2) of caffeine and trimethadione were the same, however, there was a weak correlation between the CL of caffeine and trimethadione [alone: r = 0.51 (P < 0.05); coadministered: r = 0.56 (P < 0.05)]. There were also weak correlations between the CL of trimethadione and the area under the serum concentration-time curves (AUC) of theobromine (r = -0.61, P < 0.05), paraxanthine (r = -0.69, P < 0.05) and theophylline (r = -0.60, P < 0.05), when the two drugs were administered alone. After combined administration, the correlation between the CL of trimethadione and the AUCs of the metabolites of caffeine were as follows: theobromine r = -0.63 (P < 0.05); paraxanthine r = -0.68 (P < 0.05); theophylline r = -0.65 (P < 0.05). These findings suggest that caffeine and trimethadione metabolism in healthy subjects is mediated by only in part by a form(s) of P450 enzymes involved.

13 citations

Journal ArticleDOI
Quanfei Zhu1, Chao Ma1, Huaixia Chen1, Yaqi Wu1, Jianlin Huang1 
TL;DR: In this article, a novel caffeine imprinted polymer on a stir bar was used for selective extraction of caffeine, theobromine and theophylline from beverages, and the polymerization time and quantities of reagents (template, cross-linker, porogenic solvent) were optimized.
Abstract: We have prepared a novel caffeine imprinted polymer on a stir bar that can be used for selective extraction of caffeine, theobromine and theophylline from beverages. The polymerization time and quantities of reagents (template, cross-linker, porogenic solvent) were optimized. The morphology of the molecularly imprinted polymer-coating was studied by scanning electron microscopy and Fourier transform IR spectroscopy. A rapid and sensitive method was worked out for the extraction of caffeine, theobromine and theophylline from beverages by using the molecularly imprinted stir bar followed by HPLC analysis. The effects of extraction solvent, stirring speed, desorption solvent, adsorption and desorption time were optimized. The method displays a linear response in the 5–150 μg L−1 caffein concentration range, with a correlation coefficient of >0.9904. The recoveries for three analytes in tea, carbonated and functional beverages were 91–108 %, 90–110 % and 93–109 %, with relative standard deviations ranging from 3.6–5.7 %, 3.5–7.9 % and 3.2–7.9 %, respectively. Open image in new window Figure A molecularly imprinted stir bar was prepared and applied for the selective extraction and sensitive determination of caffeine and its analogues in beverages by coupling with HPLC. The limits of detection were in the range of 1.24–2.25 μg L−1 (S/N = 3) which are lower than those in published papers

12 citations

Journal ArticleDOI
TL;DR: It is demonstrated that all three tested substances, caffeine, theophylline and theobromine inhibited the hydrolysis of tributyrin and tripalmitate catalysed by human pancreatic lipase in dose-dependent fashion.
Abstract: Methylxanthines such as caffeine, theobromine and theophylline are intensively consumed as food components by large proportion of human population all over the world. This class of compounds show various biological activities and have been found to act as broad specificity inhibitors towards numerous enzymes. However, their action on digestive enzymes have not been yet investigated. In this paper we aimed to evaluate the effects of methylxanthines on the human pancreatic lipase activity in vitro. Emulsions of short- and long-chain triglycerides (tributyrin and tripalmitate, respectively) were used as substrates. The concentrations of methylxanthines in the reaction mixtures covered the range between 0.015 mmol/L to 15 mmol/L. We demonstrated that all three tested substances, caffeine, theophylline and theobromine inhibited the hydrolysis of tributyrin and tripalmitate catalysed by human pancreatic lipase in dose-dependent fashion. The highest lipase inhibition ratios during tripalmitate and tributyrin hydrolysis were 25.74% and 79.54% respectively in the presence of caffeine, 29.89% and 62.79% respectively with theophylline and 21.08% and 67.74% respectively in the presence of theobromine. All the tested methylxanthines exert stronger inhibition in the short-chain triglyceride lipolysis comparing to long-chain substrates. Their mechanism of action involves most likely the interaction with enzyme protein but not substrate emulgation. In case of tripalmitate lipolysis all the methylxanthines showed mixed type of inhibition. Interestingly, during tributyrin lipolysis theophylline behaved as classical noncompetitive inhibitor.

12 citations

Journal ArticleDOI
TL;DR: The results show that the compounds investigated behave similarly in their interaction with p -hydroxybenzoic acid despite their differences in structure, and the suggestion is made that soluble forms of higher order may be present in solution.
Abstract: The results show that the compounds investigated behave similarly in their interaction with p -hydroxybenzoic acid despite their differences in structure. The solubilities of the complexes formed, however, appear to be markedly dependent on the structure of the parent xanthines. Only one to one species are precipitated in the systems under the conditions employed. The suggestion is made, however, that soluble forms of higher order may be present in solution.

12 citations

Journal ArticleDOI
TL;DR: It appears that isotopic effects induced by the labelling depend not only on the number of labelling atoms but also on whether this labelling is at position 1, 3 or 7 and, consequently, on the role of the labelled site on the function of the molecule.

12 citations


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Performance
Metrics
No. of papers in the topic in previous years
YearPapers
202339
202288
202122
202036
201937
201840