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.

Effect of age and smoking on in vivo CYP1A2, flavin-containing monooxygenase, and xanthine oxidase activities in Koreans: Determination by caffeine metabolism

Abstract: Objectives To assess the effect of gender, age, and smoking habits on the in vivo activities of CYP1A2, flavin-containing monooxygenase (FMO), and xanthine oxidase in Korean subjects. Methods One hundred thirty-three age- and gender-matched healthy Korean volunteers (age range, 21 to 78 years; mean age, 35.3 ± 16.6 years) with and without smoking habits participated. After drinking a cup of coffee (200 mL) that contained 110 mg caffeine, a 1-hour urine sample (between 4 and 5 hours) was collected and caffeine metabolites were analyzed by HPLC. Results There were marked individual variations in CYP1A2 [(1,7-dimethylurate + paraxanthine)/caffeine], FMO (theobromine/caffeine), and xanthine oxidase (1-methylurate/1-methylxanthine) activities (14-, 42-, and 9-fold, respectively). However, the mean values of these enzyme activities in the nonsmokers were not different between men and women. In the nonsmoking subjects in their 20s, the mean values of CYP1A2 and FMO activities (13.5 ± 5.9 and 2.1 ± 1.9, respectively) were higher than those (7.9 ± 1.8 and 0.95 ± 0.22) of older decennial age groups. Xanthine oxidase activities were the same for all age groups (subjects in their 20s through their 70s). CYP1A2 activity of the smokers (20.0 ± 9.6) was higher than that of the nonsmokers (10.8 ± 5.8; P < .001). Similarly, the FMO activity in smokers (3.4 ± 2.7) was higher than that of the nonsmokers (1.8 ± 1.7; P < .001). The xanthine oxidase activity (1.3 ± 0.5) was not increased in smokers (1.4 ± 0.5; P = .46). Conclusions Results of this caffeine metabolism study conducted with age- and gender-matched healthy Korean volunteers with and without smoking habits provided the baseline and the widely varying interindividual activities of CYP1A2, FMO, and xanthine oxidase in a Korean population. The results also suggested that drugs metabolized by CYP1A2 and FMO may require individualized dose adjustment according to the age and smoking habits of the subjects. (Clin Pharmacol Ther 2000;67:258–66.) Clinical Pharmacology & Therapeutics (2000) 67, 258–266; doi: 10.1067/mcp.2000.104617

Improved high-performance liquid chromatography method to determine theobromine and caffeine in cocoa and cocoa products.

Abstract: At present, the commonly used HPLC method for the analysis of caffeine and theobromine contents in aqueous cocoa extracts employs direct application of the extracts on the column. This practice gradually reduces the efficiency of the column and shortens its life. Also, this method gives inflated values due to interfering substances and difficulty in achieving baseline resolution. In the improved method, the interfering cocoa pigments are effectively removed by passing the aqueous extract through a Sep-pak C(18) cartridge. Subsequent injection on a C(18) reverse-phase column employing acetonitrile and water (20:80) as the mobile phase reduces the analysis time without affecting either resolution of the peak or the accuracy of caffeine and theobromine determination or achieving baseline resolution. Therefore, this method is ideally suited for rapid routine analysis of cocoa and its products.