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.

Catabolism of caffeine and purification of a xanthine oxidase responsible for methyluric acids production in pseudomonas putida l

Abstract: Caffeine catabolism and a xanthine oxidase involved in the alkaloid breakdown werestudied in Pseudomonas putida L, a strain displaying high ability to grow on this substrate.Cells cultured with unlabelled caffeine and 14 C labeled caffeine and xanthine showed thatthis alkaloid was broken-down via theobromine/paraxanthine -> 7-methylxanthine ->xanthine -> uric acid -> allantoin -> allantoic acid. Methyluric acids were formed fromthe oxidation of theobromine, paraxanthine and 7-methylxanthine, although no bacterialgrowth was observed on these compounds, indicating that this might be due to a widesubstrate specificity of xanthine oxidase. This was confirmed by activity staining in PAGEwhere activity was observed with theophylline and 3-methylxanthine, which are notinvolved in the alkaloid breakdown. A single band of activity was detected without additionof NAD + , showing an oxidase form of the enzyme. The enzyme optimum temperatureand pH were 30 o C and 7.0, respectively. The determined K

Serum metabolite/caffeine ratios as a test for liver function.

Abstract: The aim of this study was to test the usefulness of the metabolite/caffeine ratio for the evaluation of hepatic dysfunction. Subjects with liver cirrhosis and chronic hepatitis, as well as healthy volunteers, were given the oral dose of 300 mg caffeine. Blood samples were collected after 4, 8, and 12 hours. Concentrations of caffeine (CA) and its three metabolites-paraxanthine (PX), theobromine (TB), and theophylline (TP)-were determined by high-performance liquid chromatography. Pharmacokinetic parameters of caffeine and PX/CA, TB/CA, and TP/CA ratios were calculated. Elimination of caffeine was decreased in cirrhotics in comparison with healthy volunteers, as proved by the values of clearance (0.035 vs. 0.094 L/h/kg), elimination coefficient (0.061 vs. 0.153 h - 1 ), and half-life (11.4 vs. 4.3 h). Serum metabolite/caffeine ratios were significantly reduced in cirrhotic patients: PX/CA by more than 80%, TB/CA by 50% to 70%, and TP/CA by 40% to 70%. The reduction of the ratios in chronic hepatitis patients was lower and did not occur at all time points. A high correlation was found between caffeine clearance and metabolite/caffeine ratios. Metabolite/ caffeine ratios calculated in a single blood sample collected 8 or 12 hours after caffeine administration could provide a practical assessment of hepatic function in cirrhotic patients. The value of the test for the chronic hepatitis patients is limited.

Developmental variation of sugars, carboxylic acids, purine alkaloids, fatty acids, and endoproteinase activity during maturation of Theobroma cacao L. seeds.

Abstract: The changes of mono- and oligosaccharides, carboxylic acids, purine alkaloids, and fatty acid composition, and of aspartic endoproteinase activity, were analyzed during seed development in two varieties of cacao (Theobroma cacao). The majority of the components examined either decreased or accumulated steadily in concentration during the second half of bean development. Sucrose is the major sugar in the mature embryo, whereas fructose and glucose are at higher concentrations in the endosperm tissue. Considerable amounts of malate are found in the endosperm, whereas citrate is the dominant carboxylic acid in the embryo. A major change in the fatty acid composition occurs in the young embryo when the proportion of stearic acid increases rapidly at the expense of linoleic acid, which is reduced from about 18 to 3%. Theobromine is the dominant purine alkaloid (ca. 80%), and caffeine appears only toward the end of seed maturity. Aspartic endoproteinase activity increases rapidly during embryo expansion, reaching a maximal activity before final maturity. The results are discussed in conjunction with physiological changes in developing seeds, and the potential contributions of the compounds analyzed for cocoa quality.

Caffeine Formation in Tea Callus Tissue

Abstract: Callus tissue derived from segments of the stems of the tea plant produced caffeine. The caffeine was found in the tissue and was also present in the growth medium. The amount of caffeine varied with the duration and conditions of growth of the callus. Theobromine was also produced by the callus. The methylated purines appeared during the latter half of the period of the rapid phase of growth. It is probable that the caffeine was formed by those cells nearing the end of growth, maybe when the cells were autolysing. Suspensions of cells which were mechanically broken in a phosphate buffer at pH 7-2 produced more caffeine during incubation at 26 °C. If the autolysates were supplemented with RNA and methionine the amount of caffeine produced could be increased. It is suggested that the caffeine is formed during the catabolic breakdown of nucleic acids rather than directly from the pathways of purine synthesis.