Search results for "Bromine"

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…

Laser-induced plasma spectroscopy to as low as 130 nm when a gas-purged spectrograph and ICCD detection are used.

2003

An experimental setup is described for measuring laser-induced plasma emission spectra in the near vacuum UV with a Czerny-Turner spectrograph and intensified charge-coupled device under atmospheric pressure. With a simple gas-purge technique, emission lines down to 130 nm could be recorded. The strongest emission lines of bromine, chlorine, and iodine in the near vacuum UV are easily detected.

Synthesis and Inhibitory Studies of Phosphonic Acid Analogues of Homophenylalanine and Phenylalanine towards Alanyl Aminopeptidases.

2020

A library of novel phosphonic acid analogues of homophenylalanine and phenylalanine, containing fluorine and bromine atoms in the phenyl ring, have been synthesized. Their inhibitory properties against two important alanine aminopeptidases, of human (hAPN, CD13) and porcine (pAPN) origin, were evaluated. Enzymatic studies and comparison with literature data indicated the higher inhibitory potential of the homophenylalanine over phenylalanine derivatives towards both enzymes. Their inhibition constants were in the submicromolar range for hAPN and the micromolar range for pAPN, with 1-amino-3-(3-fluorophenyl) propylphosphonic acid (compound 15c) being one of the best low-molecular inhibitors …

Isolation, characterization, and computational studies of the novel [Mo3(mu3-Br)2(mu-Br)3Br6]2- cluster anion.

2010

The novel trimolybdenum cluster [Mo(3)(mu(3)-Br)(2)(mu-Br)(3)Br(6)](2-) (1, {Mo(3)}(9+), 9 d-electrons) has been isolated from the reaction of [Mo(CO)(6)] with 1,2-C(2)H(4)Br(2) in refluxing PhCl. The compound has been characterized in solution by electrospray ionization mass spectrometry (ESI-MS), UV-vis spectroscopy, cyclic voltammetry, and in the solid state by X-ray analysis (counter-cations: (n-Bu)(4)N(+) (1), Et(4)N(+), Et(3)BzN(+)), electron paramagnetic resonance (EPR), magnetic susceptibility measurements, and infrared spectroscopy. The least disordered (n-Bu)(4)N(+) salt crystallizes in the monoclinic space group C2/c, a = 20.077(2) A, b = 11.8638(11) A, c = 22.521(2) A, alpha = 9…

Variation of the BrO/SO2 molar ratio in the plume of Tungurahua volcano between 2007 and 2017 and its relationship to volcanic activity

2019

International audience; Recent long-term observations of the bromine monoxide (BrO) to sulphur dioxide (SO2) molar ratio in volcanic plumes have suggested a link between changes in the BrO/SO2 ratio and the volcanic activity. Nevertheless, understanding of the mechanisms determining this link is still limited due to the lack of studies on volcanic bromine release from the melt into the atmosphere. We present the results of 10 years (2007–2017) of observations of the BrO/SO2 molar ratio in the volcanic plume of Tungurahua volcano, Ecuador. Following the nearly continuous eruptive activity from 1999 to 2008, Tungurahua showed alternating phases of eruptive activity separated by periods of qui…

Damipipecolin and damituricin, novel bioactive bromopyrrole alkaloids from the Mediterranean sponge Axinella damicornis

2007

Two new bromopyrrole alkaloids, damipipecolin (1) and damituricin (2), have been isolated from the Mediterranean sponge Axinella damicornis, and their structures established through spectroscopic methods. Compounds 1 and 2 extend the structural variety of the so far known pyrrole alkaloids; in these compounds, the 4-bromopyrrole 2-carboxylic acid is directly condensed with a non-protein cyclic alpha-amino acid, the (2R, 4R)-trans-4-hydroxypipecolic acid and (2R, 4R)-cis-N,N'-dimethyl-4-hydroxyproline (D-turicine) in 1 and 2, respectively. Compounds 1 and 2 were found to display a modulating effect of the serotonin receptor activity in vitro.

Muon-substituted compounds in liquid bromine and water-determination of the relevant diamagnetic shieldings

1979

Conversion coefficients of the isomeric state in 72Br

2010

In order to determine the Gamow‐Teller strength distribution for the N  =  Z nucleus 72Kr an experiment was performed with a Total Absorption Gamma Spectrometer. To fully accomplish this task it is crucial to determine the multipolarity of the low energy transitions as the spin‐parity of the daughter ground state has been debated. This is done by experimental determination of the conversion coefficients. Preliminary results for the multipolarity and conversion coefficients of the transition connecting the isomeric state at 101 keV with the 72Br ground state are presented.