Salmonella T3SS-2 virulence enhances gut-luminal colonization by enabling chemotaxis-dependent exploitation of intestinal inflammation.

Salmonella Typhimurium (S.Tm) utilizes the chemotaxis receptor Tsr to exploit gut inflammation. However, the characteristics of this exploitation and the mechanism(s) employed by the pathogen to circumvent antimicrobial effects of inflammation are poorly defined.

Differences in carbon metabolic capacity fuel co-existence and plasmid transfer between Salmonella strains in the mouse gut.

Antibiotic resistance plasmids can be disseminated between different Enterobacteriaceae in the gut. Here, we investigate how closely related Enterobacteriaceae populations with similar nutrient needs can co-bloom in the same gut and thereby facilitate plasmid transfer. Using different strains of Salmonella Typhimurium (S.

Substrate Selectivity of Coumarin Derivatives by Human CYP1 Enzymes: In Vitro Enzyme Kinetics and In Silico Modeling.

Of the three enzymes in the human cytochrome P450 family 1, CYP1A2 is an important enzyme mediating metabolism of xenobiotics including drugs in the liver, while CYP1A1 and CYP1B1 are expressed in extrahepatic tissues. Currently used CYP substrates, such as 7-ethoxycoumarin and 7-ethoxyresorufin, are oxidized by all individual CYP1 forms. The main aim of this study was to find profluorescent coumarin substrates that are more selective for the individual CYP1 forms.

Molecular docking and oxidation kinetics of 3-phenyl coumarin derivatives by human CYP2A13.

CYP2A13 enzyme is expressed in human extrahepatic tissues, while CYP2A6 is a hepatic enzyme. Reactions catalysed by CYP2A13 activate tobacco-specific nitrosamines and some other toxic xenobiotics in lungs.To compare oxidation characteristics and substrate-enzyme active site interactions in CYP2A13 vs CYP2A6, we evaluated CYP2A13 mediated oxidation characteristics of 23 coumarin derivatives and modelled their interactions at the enzyme active site.

sulfonation of 7-hydroxycoumarin derivatives in liver cytosol of human and six animal species.

Sulfonation is an important high affinity elimination pathway for phenolic compounds.In this study sulfonation of 7-hydroxycoumarin and 13 its derivatives were evaluated in liver cytosols of human and six animal species. 7-hydroxycoumarin and its derivatives are strongly fluorescent, and their sulfate conjugates are nonfluorescent at excitation 405 nm and emission 460 nm.

In vitro glucuronidation of 7-hydroxycoumarin derivatives in intestine and liver microsomes of Beagle dogs.

Beagle dog is a standard animal model for evaluating nonclinical pharmacokinetics of new drug candidates. Glucuronidation in intestine and liver is an important first-pass drug metabolic pathway, especially for phenolic compounds. This study evaluated the glucuronidation characteristics of several 7-hydroxycoumarin derivatives in beagle dog's intestine and liver in vitro.

Integrated Extreme Real-Time PCR and High-Speed Melting Analysis in 52 to 87 Seconds.

Background: Extreme PCR in <30 s and high-speed melting of PCR products in <5 s are recent advances in the turnaround time of DNA analysis. Previously, these steps had been performed on different specialized instruments. Integration of both extreme PCR and high-speed melting with real-time fluorescence monitoring for detection and genotyping is presented here.

T-blocker: a simple and robust probe-free quantitative PCR assay to detect somatic mutations down to 0.1% frequency.

We have developed a simple and robust probe-free quantitative PCR (qPCR) assay method that can detect minor mutant alleles with a frequency as low as 0.1% in a heterogeneous sample by introducing a novel T-blocker concept to the allele-specific PCR method. Four new KRAS and BRAF mutation detection assays were developed and their performance was demonstrated by testing a large number of replicates, utilizing a customized PCR protocol.

Development of new Coumarin-based profluorescent substrates for human cytochrome P450 enzymes.

Cytochrome P450 (CYP) enzymes constitute an essential xenobiotic metabolizing system that regulates the elimination of lipophilic compounds from the body. Convenient and affordable assays for CYP enzymes are important for assessing these metabolic pathways. In this study, 10 novel profluorescent coumarin derivatives with various substitutions at carbons 3, 6 and 7 were developed.

Blocking oestradiol synthesis pathways with potent and selective coumarin derivatives.

A comprehensive set of 3-phenylcoumarin analogues with polar substituents was synthesised for blocking oestradiol synthesis by 17-β-hydroxysteroid dehydrogenase 1 (HSD1) in the latter part of the sulphatase pathway. Five analogues produced ≥62% HSD1 inhibition at 5 µM and, furthermore, three of them produced ≥68% inhibition at 1 µM. A docking-based structure-activity relationship analysis was done to determine the molecular basis of the inhibition and the cross-reactivity of the analogues was tested against oestrogen receptor, aromatase, cytochrome P450 1A2, and monoamine oxidases.

Structure-Activity Relationship Analysis of 3-Phenylcoumarin-Based Monoamine Oxidase B Inhibitors.

Monoamine oxidase B (MAO-B) catalyzes deamination of monoamines such as neurotransmitters dopamine and norepinephrine. Accordingly, small-molecule MAO-B inhibitors potentially alleviate the symptoms of dopamine-linked neuropathologies such as depression or Parkinson's disease. Coumarin with a functionalized 3-phenyl ring system is a promising scaffold for building potent MAO-B inhibitors.

Molecular Docking-Based Design and Development of a Highly Selective Probe Substrate for UDP-glucuronosyltransferase 1A10.

Intestinal and hepatic glucuronidation by the UDP-glucuronosyltransferases (UGTs) greatly affect the bioavailability of phenolic compounds. UGT1A10 catalyzes glucuronidation reactions in the intestine, but not in the liver. Here, our aim was to develop selective, fluorescent substrates to easily elucidate UGT1A10 function.

Identification of estrogen receptor α ligands with virtual screening techniques.

Utilization of computer-aided molecular discovery methods in virtual screening (VS) is a cost-effective approach to identify novel bioactive small molecules. Unfortunately, no universal VS strategy can guarantee high hit rates for all biological targets, but each target requires distinct, fine-tuned solutions. Here, we have studied in retrospective manner the effectiveness and usefulness of common pharmacophore hypothesis, molecular docking and negative image-based screening as potential VS tools for a widely applied drug discovery target, estrogen receptor α (ERα).

Microfluidic genotyping by rapid serial PCR and high-speed melting analysis.

Background: Clinical molecular testing typically batches samples to minimize costs or uses multiplex lab-on-a-chip disposables to analyze a few targets. In genetics, multiple variants need to be analyzed, and different work flows that rapidly analyze multiple loci in a few targets are attractive.

Methods: We used a microfluidic platform tailored to rapid serial PCR and high-speed melting (HSM) to genotype 4 single nucleotide variants.

Self-ordering of metallogrid complexes via directed hydrogen-bonding.

Reaction of imidazole aldehydes with dihydrazino derivatives of 2-phenylpyrimidine provides a family of bis(acylhydrazone) ligands which form [2 × 2] metallogrid complexes with transition metal ions including Fe(II), Co(II), Cu(II) and Zn(II). The free ligands show H-bonding interactions, both donor and acceptor, largely involving the imidazole units, while binding of the metal ions occupies all the acceptor sites and leaves only the pyrrolic-NH site as an H-bond donor, although its deprotonation by a strong base can regenerate an acceptor. These H-bonding interactions have been studied by (1)H NMR spectroscopy in solution and in the solid state by means of several crystal structure determinations.

Substituent effects on axle binding in amide pseudorotaxanes: comparison of NMR titration and ITC data with DFT calculations.

The binding behaviour of differently substituted diamide axle molecules to Hunter/Vögtle tetralactam macrocycles was studied with a combination of NMR titration, isothermal titration calorimetry (ITC) experiments and calculations employing density functional theory (DFT), along with dispersion-corrected exchange-correlation functionals. Guests with alkyl or alkenyl chains attached to the diamide carbonyl groups have a significantly higher binding affinity to the macrocycle than guests with benzoyl amides and their substituted analogues. While the binding of the benzoyl and alkenyl substituted axles is enthalpically driven, the alkyl-substituted guest binds mainly because of a positive binding entropy.

Chelate cooperativity and spacer length effects on the assembly thermodynamics and kinetics of divalent pseudorotaxanes.

Homo- and heterodivalent crown-ammonium pseudorotaxanes with different spacers connecting the two axle ammonium binding sites have been synthesized and characterized by NMR spectroscopy and ESI mass spectrometry. The homodivalent pseudorotaxanes are investigated with respect to the thermodynamics of divalent binding and to chelate cooperativity. The shortest spacer exhibits a chelate cooperativity much stronger than that of the longer spacers.

Fluorescent small molecule probe to modulate and explore α2β1 integrin function.

Collagen binding integrins are an important family of cell surface receptors that mediate bidirectionally signals between the interior of the cell and the extracellular matrix. The protein-protein interactions between cells and collagen are necessary for many physiological functions, but also promote diseases. For example, the interaction of α2β1 integrin and collagen has been shown to have an important role in thrombus formation and cancer spread.

Discriminating octahedral transition metal ions: highly selective tripodal tris-(2,2'-bipyridine) functionalized piperazine cyclophane receptor for Cu2+ ions.

New tripodal transition metal ion receptors, tris(5-ethoxycarbonyl-2,2'-bipyridine) and tris(5-carboxylate-2,2'-bipyridine) substituted 27-membered trimeric piperazine cyclophanes 5 and 7 as well as tetra(5-ethoxycarbonyl-2,2'-bipyridine) substituted 36-membered tetrameric piperazine cyclophane 6, have been prepared and their transition metal ion complexing properties studied in solution by UV-vis spectroscopy and in the solid state by single-crystal X-ray diffraction. The crystal structures of [H(3)5(3+)·Fe(2+)]·4(ClO(4)(-))·CF(3)COO(-) (V), [H(3)7(2+)·Fe(2+)]·2(SO(4)(2-)) (VII) and the reference complex [tris(5,5'-bis(ethoxycarbonyl)-2,2'-bipyridine)Fe(II) perchlorate] (I) showed that the robust piperazine cyclophane is an optimal platform in preorganizing the 2,2'-bipy moieties to form a very fixed octahedral coordination site. In an acidic water solution, the highly preorganized structure of 5 gives a [5·Fe(2+)] complex, the stability of which is comparable with the classical tris(2,2'-bipy) Fe(2+)-complex but it is a significant 3.

Unveiling electronic transitions in three novel chiral azo-compounds using linear and nonlinear circular dichroism: a theoretical-experimental study.

Herein, we report on the experimental and theoretically study of the linear absorption, electronic circular dichroism (ECD) spectra, as well as the two-photon absorption circular-linear dichroism measurements of three different chiral azo derivatives in dimethylsulfoxide solution. Using potential energy surfaces and frontier orbital analysis, we established the most stable conformation for each molecule and elucidated their different electronic transitions. Our theoretical calculations allowed us to unambiguously identify the spectral position of such transitions and correlate them with the spectral profiles observed in the two-photon absorption spectra.

Halogen bonding drives the self-assembly of piperazine cyclophanes into tubular structures.

Halogen bonding with 1,4-diiodotetrafluorobenzene leads to the self-assembly of piperazine cyclophanes into well-defined tubular structures with solvent inclusion.

Identification and quantification of proteins differentially secreted by a pair of normal and malignant breast-cancer cell lines.

Secreted proteins play a pivotal role in cellular functions. To better understand malignant behavior, we adapted stable isotopic labeling with amino acids in cell culture technology to identify and quantify proteins differentially released into the extracellular media by a pair of normal and malignant breast-cancer cell lines. Approximately 380 non-redundant proteins were quantified in serum-free media.

Genetic variation in phospholipid transfer protein modulates lipoprotein profiles in hyperalphalipoproteinemia.

We previously demonstrated the role of a phospholipid transfer protein (PLTP) gene variation (rs2294213) in determining levels of high-density lipoprotein cholesterol (HDL-C) in hypoalphalipoproteinemia (HypoA). We have now explored the role of PLTP in hyperalphalipoproteinemia (HyperA). The human PLTP gene was screened for sequence anomalies by DNA melting in 107 subjects with HyperA.

A modular "toolbox" approach to flexible branched multimacrocyclic hosts as precursors for multiply interlocked architectures.

Tetralactam macrocycles can be functionalized by a variety of cross-coupling reactions. A modular "toolbox" strategy is presented that allows 1) several tetralactam macrocycles to be covalently connected with each other or with a central spacer, 2) the macrocycles to be substituted with or connected to different chromophores, and 3) metal-coordination sites to be attached to the macrocycles. With this approach a series of different oligo-macrocyclic hosts was obtained with great structural diversity and enormous potential for further functionalization.

Terpenoids: natural inhibitors of NF-kappaB signaling with anti-inflammatory and anticancer potential.

Traditional medicine has been a fertile source for revealing novel lead molecules for modern drug discovery. In plants, terpenoids represent a chemical defense against environmental stress and provide a repair mechanism for wounds and injuries. Interestingly, effective ingredients in several plant-derived medicinal extracts are also terpenoid compounds of monoterpenoid, sesquiterpenoid, diterpenoid, triterpenoid and carotenoid groups.