ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTSelf-assembly and photophysical properties of lanthanide dinuclear triple-helical complexesClaude Piguet, Jean Claude G. Buenzli, Gerald Bernardinelli, Gerard Hopfgartner, Alan F. WilliamsCite this: J. Am. Chem. Soc. 1993, 115, 18, 8197–8206Publication Date (Print):September 1, 1993Publication History Published online1 May 2002Published inissue 1 September...

The segmental ligand 2-{6-[N,N-diethylcarbamoyl]pyridin-2-yl}-1,1'-dimethyl-5,5'-methylene-2'-(5-methylpyridin-2-yl)bis[1H-benzimidazole] (L2) reacts with stoichiometric amounts of Ln(III) (Ln = La−Nd, Sm−Tb, Tm−Lu, Y) and Zn(II) in acetonitrile to yield quantitatively selectively the heterodinuclear triple-helical complexes [LnZn(L2)3]5+ under thermodynamic control. crystal structure [EuZn(L2)3](ClO4)(CF3SO3)4(CH3CN)4 (13; EuZnC111H111N25O19F12S4Cl, monoclinic, C2/c, Z 8) shows wrapping...

Introduction Bosentan (Ro 47-0203) is a potent and mixed ETA- ETB-receptor antagonist. Its activity has been studied in variety of preclinical disease models. Methods Two double-blind placebo-controlled studies were performed to investigate the pharmacokinetics pharmacodynamics bosentan after single oral intravenous doses healthy volunteers; 3, 10, 30, 100, 300, 600, 1200, 2400 mg given ascending dose study, 50, 250, 500, 750 study (six subjects received active drug two placebo at each...

Background and purpose: The major drug‐metabolizing enzymes for the oxidation of oxycodone are CYP2D6 CYP3A. A high interindividual variability in activity these because genetic polymorphisms and/or drug–drug interactions is well established. possible role an active metabolite pharmacodynamics has been questioned importance CYP3A‐mediated effects on pharmacokinetics poorly explored. Experimental approach: We conducted a randomized crossover (five arms) double‐blind placebo‐controlled study...

As tryptic peptides and metabolites are not equally distributed along the mass range, probability of cross fragment ion interference is higher in certain windows when fixed Q1 SWATH applied. We evaluated benefits utilizing variable with regards to selectivity improvement. Variable based on equalizing distribution either precursor population (PIP) or total current (TIC) within each window were generated by an in-house software, swathTUNER. These two strategies outperformed, respect...

Background and purpose: There is high interindividual variability in the activity of drug‐metabolizing enzymes catalysing oxidation oxycodone [cytochrome P450 (CYP) 2D6 3A], due to genetic polymorphisms and/or drug–drug interactions. The effects CYP2D6 CYP3A modulation on pharmacokinetics remains poorly explored. Experimental approach: A randomized crossover double‐blind placebo‐controlled study was performed with 10 healthy volunteers genotyped for [six extensive (EM), two deficient (PM/IM)...

Matrix-assisted laser desorption/ionization mass spectrometric imaging (MALDI-MSI) was used to image the distribution of cocaine and its metabolites in intact single hair samples from chronic users down a concentration 5 ng/mg. Acquisitions were performed rastering mode, at speed 1 mm/s selected reaction monitoring (SRM) mode on MALDI triple quadrupole linear ion trap fitted with high repetition rate (1 kHz). Compared traditional methods based LC-MS/MS or GC-MS(/MS) which require segment...

Desorption electrospray ionization mass spectrometry (DESI-MS) was used as a simple and rapid way to analyze drug tablets powders without sample preparation. Experiments were performed with home-made DESI source coupled triple-quadrupole linear-ion trap (QqQ(LIT)) spectrometer. Twenty-one commercial drugs well some illicit Ecstasy analyzed. MS spectra almost exclusively showed the protonated or deprotonated ion of after directing pneumatically assisted onto tablet's surface. With tablets,...

As the mass spectrometer becomes more accepted as a detector for HPLC, its characteristics should become better understood by those performing routine LC-MS experiments. In particular, ion current response quantitative analysis studies involving significant dynamic range in concentration target analytes must be determined well other factors that affect MS response. This work describes concentration-sensitive spray (pneumatically-assisted electrospray) interface from chromatographer's...

Background and Objective Surfactants used in pharmaceutical formulations can modulate drug absorption by multiple mechanisms including inhibition of intestinal P-glycoprotein (P-gp). Our objective was to analyze the effect 2 surfactants with different affinity for P-gp vitro on bioavailability substrate talinolol humans. Methods In vitro, influence permeability studied Caco-2 cells. vivo, an open-label 3-way crossover study 9 healthy male volunteers performed. Subjects were intubated a...

Abstract A qualitative and quantitative analysis of erlotinib (RO0508231) its metabolites was carried out on rat tissue sections from liver, spleen muscle. Following oral administration at a dose 5 mg/kg, samples were analyzed by matrix‐assisted laser desorption ionization (MALDI) with mass spectrometry (MS) using an orthogonal quadrupole time‐of‐flight instrument. The parent compound detected in all tissues analyzed. following drug O ‐dealkylation could also be liver sections. Sinapinic...

Macitentan is a tissue-targeting, dual endothelin receptor antagonist, currently under phase 3 investigation in pulmonary arterial hypertension.

The identification of unknown compounds remains to be a bottleneck mass spectrometry (MS)-based metabolomics screening experiments. Here, we present novel approach which facilitates the and quantification analytes containing aldehyde ketone groups in biological samples by adding chemical information MS data. Our strategy is based on rapid autosampler-in-needle-derivatization with p-toluenesulfonylhydrazine (TSH). resulting TSH-hydrazones are separated ultrahigh-performance liquid...

Three unsymmetrical tridentate pyridine-2,6-dicarboxamide binding units have been connected to the tris(2-(N-methyl)aminoethyl)amine tripod give podand L10 that exists as a statistical mixture of four conformers in solution. In aqueous acidic medium, protonated apical nitrogen atom (pKa([L10+H]+) = 4.66(2)) adopts an endo conformation compatible with formation bi- and trifurcated hydrogen bonds oxygen atoms proximal carboxamide groups, thus producing clipped preorganized for complexation...

The application of a new hybrid RF/DC quadrupole-linear ion trap mass spectrometer to support drug metabolism and pharmacokinetic studies is described. instrument based on quadrupole path capable conventional tandem spectrometry (MS/MS) as well several high-sensitivity MS scans using the final linear trap. Several pharmaceutical compounds, including trocade, remikiren tolcapone, were used evaluate capabilities system with positive negative turbo ionspray, either information-dependent data...