Topic
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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TL;DR: Gr66a is the first gustatory receptor shown to be essential for caffeine-induced behavior and activity of gustatory receptors cells in vivo, and further support the role of Gr66a rather than a PDE in mediating the caffeine response.
238 citations
TL;DR: The potency of xanthine derivatives as adenosine antagonists was studied in fat cells and hippocampal slices (A2-receptors) and on L-[3H]phenylisopropyladenosine (PIA) binding in membranes from rat cortex.
220 citations
Journal Article•
TL;DR: A simple, rapid and accurate ultraviolet spectrophotometric method for the determination of theophylline and theobromine in biological fluids has been developed and application to the tissue of rabbits and mice has been shown.
Abstract: 1. A simple, rapid and accurate ultraviolet spectrophotometric method for the determination of theophylline and theobromine in biological fluids has been developed. 2. The method offers satisfactory precision and a sensitivity of 1.0 microgm. per cc. 3. Application of the method to the tissue of rabbits and mice has been shown. 4. Theophylline has been demonstrated to be restricted to the plasma of the circulating blood. 5. Theophylline has been demonstrated to be very loosely bound to the plasma proteins. 6. The tissue level of theophylline following intravenous administration has been found to parallel the blood level in its rate of fall.
218 citations
TL;DR: The construction of transgenic coffee plants are described in which expression of the gene encoding theobromine synthase (CaMXMT1) is repressed by RNA interference (RNAi), indicating that it should be feasible to produce coffee beans that are intrinsically deficient in caffeine.
Abstract: The demand for decaffeinated coffee is increasing because the stimulatory effects of caffeine can adversely affect sensitive individuals by triggering palpitations, increased blood pressure and insomnia1. Three N-methyltransferase enzymes are involved in caffeine biosynthesis in coffee plants — CaXMT1, CaMXMT1 (theobromine synthase) and CaDXMT1 (caffeine synthase), which successively add methyl groups to xanthosine in converting it into caffeine2,3,4. Here we describe the construction of transgenic coffee plants in which expression of the gene encoding theobromine synthase (CaMXMT1) is repressed by RNA interference (RNAi). The caffeine content of these plants is reduced by up to 70%, indicating that it should be feasible to produce coffee beans that are intrinsically deficient in caffeine.
217 citations
Journal Article•
TL;DR: The results lead to the observation that caffeine and its metabolites may also contribute to the overall antioxidant and chemopreventive properties of caffeine-bearing beverages, such as tea.
Abstract: Background Caffeine, along with its catabolic products theobromine and xanthine, is a key component of tea and coffee. These compounds are structurally similar to uric acid, a known antioxidant which is present in blood at relatively high concentrations, but also shows prooxidant activity. In view of the structural similarity between uric acid and caffeine and its metabolites, we studied the antioxidant and prooxidant properties of these compounds. Material/methods Antioxidant activity was determined by measuring the quenching effect of the compounds on oxidative DNA degradation by a hydroxyl radical generating system. Prooxidant activity was studied by measuring the ability of the compounds to oxidatively degrade DNA in the presence of copper ions. Results Caffeine, theobromine and xanthine have a quenching effect on the production of hydroxyl radicals, as well as on oxidative DNA breakage by hydroxyl radicals. Consistent with previous observations that many known antioxidants of plant origin are also capable of prooxidant action, the purine alkaloids also show oxidative DNA breakage in the presence of transition metal ions. Conclusions The alkaloid caffeine and its catabolic products theobromine and xanthine exhibit both antioxidant and prooxidant properties. The results lead to the observation that caffeine and its metabolites may also contribute to the overall antioxidant and chemopreventive properties of caffeine-bearing beverages, such as tea.
215 citations