Mode-of-action studies of the novel bisquaternary bisnaphthalimide MT02 against Staphylococcus aureus.

Screening of various bisquaternary bisnaphthalimides against a variety of human pathogens revealed one compound, designated MT02, with strong inhibitory effects against Gram-positive bacteria. The MICs ranged from 0.31 μg/ml against community-acquired methicillin-resistant Staphylococcus aureus (MRSA) lineage USA300 to 20 μg/ml against Streptococcus pneumoniae.

Comparison of established and novel purity tests for the quality control of heparin by means of a set of 177 heparin samples.

The widespread occurrence of heparin contaminated with oversulfated chrondroitin sulfate (OSCS) in 2008 initiated a comprehensive revision process of the Pharmacopoeial heparin monographs and stimulated research in analytical techniques for the quality control of heparin. Here, a set of 177 heparin samples from the market in 2008 as well as pure heparin sodium spiked with defined amounts of OSCS and DS were used to evaluate established and novel methods for the quality control of heparin. Besides (1)H nuclear magnetic resonance spectroscopy (NMR), the assessment included two further spectroscopic methods, i.

N-(3-Cyanophenyl)-2-phenylacetamide, an effective inhibitor of morbillivirus-induced membrane fusion with low cytotoxicity.

Based on the structural similarity of viral fusion proteins within the family Paramyxoviridae, we tested recently described and newly synthesized acetanilide derivatives for their capacity to inhibit measles virus (MV)-, canine distemper virus (CDV)- and Nipah virus (NiV)-induced membrane fusion. We found that N-(3-cyanophenyl)-2-phenylacetamide (compound 1) has a high capacity to inhibit MV- and CDV-induced (IC(50) μM), but not NiV-induced, membrane fusion. This compound is of outstanding interest because it can be easily synthesized and its cytotoxicity is low [50 % cytotoxic concentration (CC(50)) ≥ 300 μM], leading to a CC(50)/IC(50) ratio of approximately 100.

Comparison of chiral electrophoretic separation methods for phenethylamines and application on impurity analysis.

A chiral microemulsion electrokinetic chromatography method has been developed for the separation of the enantiomers of the phenethylamines ephedrine, N-methylephedrine, norephedrine, pseudoephedrine, adrenaline (epinephrine), 2-amino-1-phenylethanol, diethylnorephedrine, and 2-(dibutylamino)-1-phenyl-1-propanol, respectively. The separations were achieved using an oil-in-water microemulsion consisting of the oil-component ethyl acetate, the surfactant sodium dodecylsulfate, the cosurfactant 1-butanol, the organic modifier propan-2-ol and 20mM phosphate buffer pH 2.5 as aqueous phase.

Alternatives to amino acid analysis for the purity control of pharmaceutical grade L-alanine.

The quality control of drugs is important for safety of patients and consumers. International pharmacopoeias mostly employed HPLC with UV detection for this purpose. This is always a problem when the drugs, such as most amino acids, are lacking a chromophor.

Composition of OSCS-contaminated heparin occurring in 2008 in batches on the German market.

In 2008, some 900 cases of adverse events associated with the use of heparin were reported to the Food and Drug Administration of USA and the Federal Institute of Drugs and Medical Devices in Germany. 238 patients died from heparin in the USA. In March 2008, oversulfated chondroitin sulfate (OSCS) was identified to be responsible for these cases.

The bisnaphthalimides as new active lead compounds against Plasmodium falciparum.

The bisquaternary bisnaphthalimides are a versatile class of compounds being active against the malaria parasite Plasmodium falciparum in the lower nanomolar range of concentration combined with no cytotoxicity. The series of compounds is designed as choline analogues and interfering agents of the phosphatidylcholine biosynthesis. The qualitative analysis of the structure-activity relationships (SAR) revealed the importance of a long methylene middle chain of at least 8 methylene groups between the two bisquaternary naphthalimides or a monoquaternary naphthalimide consisting of a long alkyl chain attached to the positively charged nitrogen atom.

Competitive inhibition of renal tubular secretion of ciprofloxacin and metabolite by probenecid.

Aims: Probenecid influences transport processes of drugs at several sites in the body and decreases elimination of several quinolones. We sought to explore extent, time course, and mechanism of the interaction between ciprofloxacin and probenecid at renal and nonrenal sites.

Methods: A randomized, two-way crossover study was conducted in 12 healthy volunteers (in part previously published Clin Pharmacol Ther 1995; 58: 532-41).

Use of evaporative light scattering detection for the quality control of drug substances: influence of different liquid chromatographic and evaporative light scattering detector parameters on the appearance of spike peaks.

High performance liquid chromatography (HPLC) with evaporative light scattering detection (ELSD) is a versatile, easy to use and inexpensive alternative when it comes to the analysis of substances lacking a chromophor for UV detection. However, in pharmaceutical analysis injection of highly concentrated test solutions are normally required to control impurities at low levels. Under these conditions spike peaks were observed in the chromatograms of the test solutions making a proper evaluation of the impurity profile impossible.

Interaction of (benzylidene-hydrazono)-1,4-dihydropyridines with beta-amyloid, acetylcholine, and butyrylcholine esterases.

Approved drugs for the treatment of Alzheimer's disease belong to the group of inhibitors of the acetylcholinesterase (AChE) and NMDA receptor inhibitors. However none of the drugs is able to combat or reverse the progression of the disease. Thus, the recently reported promising multitarget-directed molecule approach was applied here.

Rational design of dualsteric GPCR ligands: quests and promise.

Dualsteric ligands represent a novel mode of targeting G protein-coupled receptors (GPCRs). These compounds attach simultaneously to both, the orthosteric transmitter binding site and an additional allosteric binding area of a receptor protein. This approach allows the exploitation of favourable characteristics of the orthosteric and the allosteric site by a single ligand molecule.

Population pharmacokinetic comparison and pharmacodynamic breakpoints of ceftazidime in cystic fibrosis patients and healthy volunteers.

Despite the promising activity of ceftazidime against Pseudomonas aeruginosa and Burkholderia cepacia, there has not yet been a study that directly compared the pharmacokinetics (PK) of ceftazidime in cystic fibrosis (CF) patients and healthy volunteers by population PK methodology. We assessed the population PK and PK/pharmacodynamic (PD) breakpoints of ceftazidime in CF patients and healthy volunteers. Eight CF patients (total body weight [WT] [average +/- standard deviation] = 42.

The role of solvents in the signal separation for quantitative (1)H NMR spectroscopy.

Compared to conventional means of quantitative drug analysis, NMR spectroscopy only provides a limited set of adjustable parameters to enhance the quality of the analysis such as pH value, temperature, auxiliary reagents, magnetic field strength or properties of the solvent. In this work we investigate the influence of the kind of solvent on the signal separation of decisive resonances in the NMR spectra of codergocrine mesilate and flupentixol dihydrochloride. Polarity and aromaticity of the solvent play a crucial role in the optimization of signal separation.

4-[(2E)-2-(4-Chloro-benzyl-idene)hydrazinyl-idene]-1-methyl-1,4-dihydro-pyridine monohydrate.

In the title compound, C(13)H(12)ClN(3)·H(2)O, the organic mol-ecule is almost planar, with a dihedral angle of 3.22 (10)° between the benzene and pyridine rings. The crystal structure is stabilized by O-H⋯N and C-H⋯O hydrogen bonding and π-π stacking inter-actions [centroid-centroid distances = 3.