Search results for "theobromine"
showing 10 items of 10 documents
A rapid procedure for the determination of caffeine, theophylline and theobromine in urine by micellar liquid chromatography and direct sample inject…
1995
Abstract A liquid chromatographic procedure for the determination of caffeine, theophylline and theobromine in urine samples is described. The proposed system uses a Spherisorb octadecyl-silane ODS-2 C18 analytical column and a guard column of similar characteristics. The UV detector was set at 273 nm. A study to adequately select the composition of the micellar mobile phase for the separation of these compounds in urine samples is performed. Maximum resolution was achieved with a 0.075 M sodium dodecylsulphate-1.5% propanol eluent. Limits of detection at 273 nm ranged between 0.4 μg/ml for theobromine and theophylline and 1.2 μg/ml for caffeine. The procedure allows the determination of th…
Polyphenols, methylxanthines, fatty acids and minerals in cocoa beans and cocoa products
2019
In this study, the nutritional profile and some health benefit of three cocoa bean samples of different origins, including Perù, Ecuador (Criollo) and Ghana (Hybrid) and five samples of cocoa products from Criollo variety at different percentage of cocoa solids (from 70 to 100%), are investigated. The Ecuadorian beans were of the same batch used to obtain the chocolate samples (70% cocoa solids) by processing without conching. All samples were analyzed for their proximate composition, mineral content, fatty acids, total polyphenols, catechin, epicathechin theobromine and caffeine. Fatty acid profiles of the cocoa products were quite similar to those obtained in cocoa beans. The atherogenici…
Inhibitory responses to exogenous adenosine in murine proximal and distal colon”
2006
The aims of the present study were firstly, to characterize pharmacologically the subtypes of P(1) purinoreceptors involved in the inhibitory effects induced by exogenous adenosine in longitudinal smooth muscle of mouse colon, and secondly, to examine differences in the function and distribution of these receptors between proximal and distal colon. Adenosine (100 microM-3 mM) caused a concentration-dependent reduction of the amplitude of spontaneous contractions in the proximal colon, and muscular relaxation in the distal colon. In the proximal colon, adenosine effects were antagonized by a selective A(1) receptor antagonist, 1,3-dipropyl-8-cyclopentylxanthine (DPCPX, 10 nM), but were not m…
The potential link between episodes of diverticulitis or hemorrhoidal proctitis and diets with selected plant foods : a case-control study
2021
Diverticulitis and hemorrhoidal proctitis in the population are significant public health problems. We studied the potential association between the intake of certain plant foods and diverticulitis or hemorrhoidal episodes through a case–control study including 410 cases and 401 controls. We used a semiquantitative food frequency questionnaire. The intake was additionally quantified according to a 24 h recall. The plant foods or derived food products were categorized by their main chemical components into ethanol, caffeine/theine/theobromine, capsaicin, alliin, acids, eugenol, and miscellaneous foods such as curcumin. The mean score for overall intake of plant foods under consideration was …
A metabolomics-driven approach to predict cocoa product consumption by designing a multimetabolite biomarker model in free-living subjects from the P…
2014
Scope The aim of the current study was to apply an untargeted metabolomics strategy to characterize a model of cocoa intake biomarkers in a free-living population. Methods and results An untargeted HPLC-q-ToF-MS based metabolomics approach was applied to human urine from 32 consumers of cocoa or derived products (CC) and 32 matched control subjects with no consumption of cocoa products (NC). The multivariate statistical analysis (OSC-PLS-DA) showed clear differences between CC and NC groups. The discriminant biomarkers identified were mainly related to the metabolic pathways of theobromine and polyphenols, as well as to cocoa processing. Consumption of cocoa products was also associated wit…
Cytochrome P450-dependent metabolism of caffeine in [i]Drosophila melanogaster[/i]
2014
Caffeine (1, 3, 7-trimethylxanthine), an alkaloid produced by plants, has antioxidant and insecticide properties that can affect metabolism and cognition. In vertebrates, the metabolites derived from caffeine have been identified, and their functions have been characterized. However, the metabolites of caffeine in insects remain unknown. Thus, using radiolabelled caffeine, we have identified some of the primary caffeine metabolites produced in the body of Drosophila melanogaster males, including theobromine, paraxanthine and theophylline. In contrast to mammals, theobromine was the predominant metabolite (paraxanthine in humans; theophylline in monkeys; 1, 3, 7-trimethyluric acid in rodents…
Effects of alkylxanthines on contractility of diaphragm fibres isolated from normal and sensitized guinea-pigs.
1993
Abstract This study investigates the effects of alkylxanthines on twitch tension generated by electrical stimulation (supramaximal pulses, 0·2 ms duration, 1 Hz) of diaphragm muscle fibres isolated from normal and actively-sensitized guinea-pigs. Caffeine, theophylline and theobromine increased, in a concentration-dependent manner (50–500 μm), twitch tension in normal and sensitized diaphragm. Caffeine (500 μm) enhanced contractility to a greater extent than theophylline or theobromine. Twitch potentiation by caffeine (500 μm) was significantly greater in sensitized diaphragm. Verapamil (0·1–100 μm) did not alter twitch contractions in the absence or presence of alkylxanthines in normal or …
Double-blind, crossover study of the clinical efficacy and the hemorheological effects of pentoxifylline in patients with occlusive arterial disease …
1984
The effect of a 3 month daily administration of 800 mg pentoxifylline (Trental 400 bds) or placebo was assessed under double blind crossover design in 18 patients (12 males and 6 females) with peripheral occlusive arterial disease in respect of painfree walking distance and various hemorheological and hemostasiological variables, platelet aggregation, serum cholesterol and triglycerides. In first treatment period walking distance significantly increased with pentoxifylline by 46% from baseline 121 ± 15 m and by 4% with placebo from baseline 134 ± 18 m. Pentoxifylline administration furthermore yielded significant decrease in whole blood and plasma viscosity and significant increase in eryt…
Die Wirkung von Theophyllin, Coffein und Theobromin auf Kontraktionskraft, Erregbarkeit, Refrakt�rzeit und Spontanfrequenz des isolierten Herzmuskels…
1956
In the electrically driven papillary muscle of the cat's right ventricle theophylline, caffeine and theobromine exerted a positive inotropic action. Log. dose-effect regression lines for the three drugs were parallel; the effect of theophylline was significantly greater than those of caffeine and theobromine. The range of concentrations used was 1/32–1/2 mM/1.
On-line in-tube solid phase microextraction coupled to capillary liquid chromatography-diode array detection for the analysis of caffeine and its met…
2019
Abstract In-tube solid phase microextraction (IT-SPME) coupled on-line to capillary liquid chromatography with diode array detection provides a simple and fast analytical methodology for the simultaneous quantitation of caffeine and its three primary metabolites (theobromine, paraxanthine and theophylline) in micro samples of serum, saliva and urine matrices. The sample amount required for one analysis was only 2.5 μL of saliva, 6.25 μL of serum or 40 μL of urine, a requirement for its implementation in a hospital laboratory for preterm newborns, where sample availability is a major problem. In standard conditions, 25 μL of diluted saliva or serum (or 100 μL of urine) were processed by IT-S…