Caffeine is synthesized from xanthosine through N-methylation and ribose removal steps. In the present study, three types of cDNAs encoding N-methyltransferases were isolated from immature fruits of coffee (Coffea arabica) plants, and designated as CaXMT1, CaMXMT2, and CaDXMT1, respectively. The bacterially expressed encoded proteins were characterized for their catalytic properties. CaXMT1 cat...

There is a great call for using microbial bio-decaffeination approach to remove caffeinefrom caffeinated products and industrial wastes. We aimed in this study to screen strainsof yeasts which exhibit high caffeine tolerance and to investigate the bio-degradation ofcaffeine under growth conditions. Sixteen yeast strains were isolated from the cultivatedtea soils collected from sites of northern...

Caffeine, a purine alkaloid drug, has been recognized as a contaminant of water bodies in various climatic regions, however, these environmental caffeine concentrations are the first to be reported in the tropical Caribbean. The major objective of this study was to develop an improved method to extract caffeine from surface and wastewaters in the warm Caribbean environment and measure caffeine ...

Abstract Fe/Ti-based compounds were synthesized from ferro-titaniferous mineral sands using aqueous oxalic acid under subcritical water (sCW) conditions (135°C/50 bar/4 h) and their photocatalytic activity was evaluated against methylene blue or caffeine UV-A visible radiation. The X-ray diffraction Raman spectroscopy analyses revealed that the as-synthetized mainly comprised of ferrous oxalate...

The aim of this investigation was to determine the use of caffeine by athletes after its removal from the World Anti-Doping Agency list. For this purpose, we measured the caffeine concentration in 20 686 urine samples obtained for doping control from 2004 to 2008. We utilized only urine samples obtained after official national and international competitions. Urine caffeine concentration was det...

The concentrations of 12 pharmaceutical compounds (atenolol, erythromycin, cyclophosphamide, paracetamol, bezafibrate, carbamazepine, ciprofloxacin, caffeine, clarithromycin, lidocaine, sulfamethoxazole and N-acetylsulfamethoxazol (NACS)) were investigated in the influents and effluents of two hospital wastewater treatment plants (HWWTPs) in Saudi Arabia. The majority of the target analytes wer...

Caffeine causes most of its biological effects via antagonizing all types of adenosine receptors (ARs): A1, A2A, A3, and A2B and, as does adenosine, exerts effects on neurons and glial cells of all brain areas. In consequence, caffeine, when acting as an AR antagonist, is doing the opposite of activation of adenosine receptors due to removal of endogenous adenosinergic tonus. Besides AR antagon...

Antipyrylazo III myoplasmic calcium transients were recorded in cut skeletal muscle fibres of the frog (Rana esculenta), using the double vaseline-gap voltage-clamp system. Intracellular calcium removal mechanisms were analysed, using a slightly modified model taken from the literature. Parameter values reported here are generally consistent with those obtained by the original model. Caffeine (...

We investigated the roles of sodium-calcium exchange, sarcoplasmic reticulum, and mitochondria in Cai homeostasis in cultured chick ventricular cells. Specifically, the influence of low sodium medium on contractile state, calcium fluxes, and cytosolic free [Ca] [( Ca]i) was examined. [Ca]i was measured using fura-2. Mean [Ca]i in control medium was 126 +/- 14 nM. Exposure of cells to sodium-fre...

This work evaluated caffeine removal in a vertical flow constructed wetland (VFCW), planted with Vetiveria zizanioides. The feeding was continuous (synthetic influent: mineral medium and caffeine) to reduce the concentration variations bed. Two influent concentrations (0.75 ± 1.0 mg·L−1 1.5 mg·L−1) were used constant hydraulic load (100 10 L·m−2·d−1). Plant growth monitored weekly, characteriza...