109 research outputs found
Cyanooxime Inhibitors of Carbonyl Reductase and Methods of Using Said Inhibitors in Treatments Involving Anthracyclines
Compositions of matter for treating cancer patients are used to prevent or limit cardiotoxicity during or after treatment with anthracycline drugs, and to prevent or lower resistance to anthracycline drugs, both of which are believed to be caused by the human enzyme carbonyl reductase. Preferred embodiments comprise a pharmaceutical composition comprising compounds having halogenated (or pseudo-halogenated) aryl groups, preferably halogenated (or pseudo-halogenated) arylcyanooximes or phenylcyanooximes and derivatives or analogs thereof, including those comprising --CL or --F, or other substituents on an aryl/phenyl ring. The preferred composition of arylcyanooxime(s) may be administered in a pharmaceutical composition also comprising at least one anthracycline compound, or may be administered separately from the at least one anthracycline compound
Biphenyl Inhibitors of Carbonyl Reductase
Compositions of matter and methods of treating cancer patients may prevent or limit cardiotoxicity during or after chemotherapy, and/or may prevent or lower resistance to anthracycline drugs, both of which are believed to be caused by the human enzyme carbonyl reductase. Thus, the compositions and methods may be used to reduce the dosages of anthracycline anti-cancer drugs necessary to produce a desired cancer-cell-killing performance. Preferred embodiments comprise treating cancer patients with a pharmaceutical composition comprising biphenyl compounds having two halogenated (or pseudo-halogenated) and/or hydroxylated, aryl groups that are linked by a bridging atom. The preferred composition of biphenyl compound(s) may be administered in a pharmaceutical composition also comprising at least one anthracycline compound, or may be administered separately than the at least one anthracycline compound. Especially-preferred biphenyl compounds include triclosan, hexachlorophene, and dichlorophene
Assesing use and suitability of scanning electron microscopy in the analysis of micro remains in dental calculus
Dental calculus is increasingly recognized as a major reservoir of dietary information. Palaeodietary studies using plant and animal micro remains (e.g. phytoliths, pollen, sponge spicules, and starch grains) trapped in calculus have the potential to revise our knowledge of the dietary role of plants in past populations. The conventional methods used to isolate and identify these micro remains rely on removing them from their microenvironment in the calculus, thus the microenvironment that traps and preserves micro remains is not understood. By using scanning electron microscopy and energy dispersive X-ray spectroscopy (SEMeEDX) on modern chimpanzee calculus from the Taï Forest, Côte d¿Ivoire, and human calculus from the Chalcolithic site of Camino del Molino, Spain, we present the first reported observations on characteristics of the matrix setting that are conducive to the survival of starch in dental calculus. We also assess the potential for SEMeEDX to detect starch and differentiate it from structurally and molecularly similar substrates. We demonstrate that SEMeEDX may offer a nondestructive technique for studying micro remains in certain contexts. Finally, we compare traditional optical analytical techniques (OM) with less invasive electron microscopy. The results indicate that SEM-EDX and OM are both effective for observing micro remains in calculus, but differ in their analytical resolution to identify different micro remains, and we therefore recommend a sequential use of both techniques
Fast Homozygosity Mapping and Identification of a Zebrafish ENU-Induced Mutation by Whole-Genome Sequencing
Forward genetics using zebrafish is a powerful tool for studying vertebrate development through large-scale mutagenesis. Nonetheless, the identification of the molecular lesion is still laborious and involves time-consuming genetic mapping. Here, we show that high-throughput sequencing of the whole zebrafish genome can directly locate the interval carrying the causative mutation and at the same time pinpoint the molecular lesion. The feasibility of this approach was validated by sequencing the m1045 mutant line that displays a severe hypoplasia of the exocrine pancreas. We generated 13 Gb of sequence, equivalent to an eightfold genomic coverage, from a pool of 50 mutant embryos obtained from a map-cross between the AB mutant carrier and the WIK polymorphic strain. The chromosomal region carrying the causal mutation was localized based on its unique property to display high levels of homozygosity among sequence reads as it derives exclusively from the initial AB mutated allele. We developed an algorithm identifying such a region by calculating a homozygosity score along all chromosomes. This highlighted an 8-Mb window on chromosome 5 with a score close to 1 in the m1045 mutants. The sequence analysis of all genes within this interval revealed a nonsense mutation in the snapc4 gene. Knockdown experiments confirmed the assertion that snapc4 is the gene whose mutation leads to exocrine pancreas hypoplasia. In conclusion, this study constitutes a proof-of-concept that whole-genome sequencing is a fast and effective alternative to the classical positional cloning strategies in zebrafish
A Role for Methionine 234 in the Substrate Specificity of Human Carbonyl Reductase
Doxorubicin, daunorubicin and many other anthracyclines make up some of the most popular chemotherapy drugs used today. Once absorbed into the body, the naturally occurring enzyme Human Carbonyl Reductase 1 (HCBR1) has been shown to catalyze the NADPH-dependent reduction of these anthracyclines. This reaction produces alcohol metabolites that contain dangerous cardiotoxic properties. Discovering a way to advance anthracyclines so they no longer represent substrates for HCBR1 can possibly eliminate the amount of cardiotoxic side effects produced by the drugs. The focus of this study is to determine the possible role of methionine 234 in binding and substrate specificity of HCBR1 and to gain more of an understanding as to how HCBR1 binds small molecules within its active site. Steady-state kinetics were performed with a mutant HCBR1 where MET234 was replaced with an alanine. The catalytic efficiency with menadione (carbonyl substrate) was decreased by 0.041 as compared to the wild-type. This diminished efficiency suggests a role for MET234 in orienting the carbonyl substrate for catalysis
Synthesis, Properties and Crystal Structure of the 2,4-Dichlorophenyl-Cyanoxime: A Powerful Carbonyl Reductase Inhibitor
The compound 2,4-dichlorophenylcyanoxime (later H(2,4-diCl-PhCO)) has significance in its possible application in cancer chemotherapy treatments since it acts as an inhibitor of the human carbonic reductase. This enzyme decreases the effectiveness of anthracycline drug treatment of some types of cancer. The compound was synthesized in high yield at ambient conditions from 2,4-dichlorophenylacetonitrile, using gaseous methylnitrite. The compound was characterized by means of UV–visible, IR, 1H, 13C NMR spectroscopy and X-ray analysis. The cyanoxime crystallizes in a monoclinic space group P21/c (#14) with unit cell constants: a = 3.7587(9) Å, b = 30.087(7) Å, c = 7.6874(17) Å, β = 96.163(3)°; V = 864.3(3) Å3, Z = 4. The structure was solved, using direct methods, to final R indices [I \u3e 2σ (I)] R1 = 0.0551 (wR2 = 0.1217). The compound adopts a non-planar, trans-anti configuration with the value of the dihedral angle between the cyanoxime and dichlorophenyl planes equal to 50.61°
Preparation, Properties and Crystal Structure of \u3cem\u3eSyn\u3c/em\u3e-Isomer of 2,6-Dichlorophenyl-Cyanoxime, H(2,6-diCl-PhCO): Potent \u3cem\u3eCarbonyl Reductase\u3c/em\u3e Inhibitor
The oximino(2,6-dichlorophenyl)acetonitrile, H(2,6-diCl-PhCO) has been synthesized in a reasonably high yield of 60%, and characterized using a variety of physical, electrochemical, spectroscopic methods and X-ray analysis. This compound belongs to the family of cyanoximes; a new subclass of oximes with the general formula NC–C(=N–OH)–R (where R is an electron-withdrawing group) which recently emerged as new biologically active compounds. This cyanoxime represents a disubstituted arylcyanoxime that was found to be a powerful inhibitor of the Carbonyl Reductase enzyme involved in the developing of resistance to anticancer treatment, and the making of cardiotoxic derivatives of anthracyclines that are currently used in medicine. The oximino(2,6-dichlorophenyl)acetonitrile, H(2,6-diCl-PhCO) is a weak acid with pKa = 6.17 and does not dissociate in organic polar protic and aprotic solvents. The cyanoxime was obtained as a microcrystalline mixture of two diastereomers (anti- and syn-) and deprotonates in solutions with the formation of yellow anions which exhibit solvatochromic behavior. However, one specific diastereomer—syn—was isolated in crystalline form from a solvent system as colorless blocks overlayed with pentane ether solution in a monoclinic system in a P2/c (#13) space group with unit cell parameters:  = 8.1720(2),  = 8.8013(3),  = 13.0146(4) and β = 102.546(3); Z = 4. A single crystal was studied using filtered CuKa radiation, providing Rint value of 0.0348 from a full-sphere of reflections. A crystal structure was solved using direct methods, and well refined to R1 = 0.0459, wR2 = 0.1268 and GOF = 1.107. The studied specimen of oximino(2,6-dichlorophenyl)acetonitrile, H(2,6-diCl-PhCO), represents a highly non-planar, rare syn-diastereomer in which the oxime fragment is positioned towards the chlorinated phenyl group. In the crystal, the compound forms a columnar structure extended along the c-direction by using slipped π–π stacking interactions. Columns are interconnected via H-bonding between the oxime OH-group and N atom of the nitrile group with the following parameters: N–H = 1.841 Å, and 169.20° N···H–O angle. No thermal interconversion of syn- into anti- diastereomer was observed upon heating of crystals of one isomer under flow of Ar
Les retombées économiques en termes d'emplois liées à l'éventuelle localisation des activités de DHL en Wallonie
Les retombées économiques en termes d'emplois liées à l'éventuelle localisation des activités de DHL en Walloni
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