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.

RP-HPLC and transcript profile indicate increased leaf caffeine in Coffea canephora plants by light

Abstract: Light is a survival quotient for all photosynthetic plants and its reception is very complex due to direct regulation by photoreceptors and their downstream transcriptional factors or indirectly by circadian rhythm. Shade-grown coffee cultivation though less productive than the sun tolerant varieties, pose high potential as benefit to the environment. Other than high nutrient soil associated with shade-cultivated coffee, light is another important difference when compared to full sun cultivation practice. It is thus important to study if light has a role in accumulation of caffeine - the most undesired compound in coffee. Light irradiation of suspension cultures of Coffea arabica enhances caffeine content. However, no such study is available on whole plants, which are anticipated to act in accord with organismal homeostasis. Moreover, the promoter of theobromine synthase-like gene involved in caffeine biosynthesis carries several light responsive motifs. In this report, it is shown that in complete darkness the caffeine content in young leaves of 1 year old seedlings is very low (0.094±0.003 mg/100 mg tissue dw.). However, it increases to 5.9 folds within 6hrs of exposure to light. In addition, caffeine content drops (0.218±0.03; mg/100 mg tissue dw.) when light exposed plants are returned to complete dark. Transcript analysis further reveals that this difference is due to regulation of the caffeine biosynthetic genes. A further discussion to the effect of dark and light on levels of caffeine is also provided. Though cup quality of shade-grown coffee is indefinite, this study clearly demonstrates the role of light in regulation of caffeine biosynthesis.

Setschenow coefficients for caffeine, theophylline and theobromine in aqueous electrolyte solutions

Abstract: Setschenow coefficient measurements have been made on methylated xanthines (caffeine, theophylline and theobromine) in several inorganic and organic aqueous salt solutions at 298 K. In general, the order of salting effect is similar for the three solutes and can be rationalized as a consequence of structural salt–water interactions. Scaled particle theory and the Cross and McTigue equation have been employed to compare theoretical and experimental salting constants.

Potentiating effects of methylxanthines on teratogenicity of mitomycin C in mice

Abstract: A previous study demonstrated that caffeine strongly potentiated the teratogenic action of mitomycin C in mice. In the present study the effect of methylxanthines including caffeine, theophylline, theobromine (theobromine sodium salicylate), paraxanthine, and 1-methylxanthine was compared in order to analyze the structure-activity relationship. Jcl:ICR mice were injected IP with 3 mg/kg of mitomycin C, immediately followed by SC injection of each methylxanthine on day 11 of gestation. The doses of methylxanthines were calculated so that the mice received 50 mg/kg of caffeine or the equimolecular amount of the other methylxanthines. Fetuses were examined for external malformations on day 18 of gestation. Mitomycin C at 3 mg/kg and the methylxanthines at the doses used were not teratogenic. Combined administration of caffeine or theophylline with mitomycin C produced more than 80% of malformed fetuses. Although less effective than caffeine or theophylline, paraxanthine also significantly increased the incidence of malformed fetuses. Theobromine and 1-methylxanthine were virtually ineffective. From these findings, it is suggested that the methyl group at N-1 position of the xanthines is important for the enhancement but the N-1 methylation alone is ineffective unless accompanied with the substitution of the methyl moiety at the other position(s).