Photo-ionization spectroscopy and mass spectrometry of some molecular and supramolecular asymmetric systems in the isolated state.

abstract：:The programmed assembly of p-octiphenyl rods carrying six complementary tripeptide strands was studied in the presence of bilayer membranes using circular dichroism (CD) spectroscopy. Thermal CD experiments demonstrated programmed assembly of anionic and cationic rods into supramolecules at low temperature that irreve...

journal_title：Chirality

authors： Sakai N,Matile S

更新日期：2004-01-01 00:00:00

abstract：:A molecular docking study, using molecular mechanics calculations with AutoDock and semi-empirical PM3 calculations, was used to predict the enantiodiscrimination of heptakis(2,3,6-tri-O-methyl)-β-cyclodextrin (TMβCD) and ketoconazole (KTZ) enantiomers. A Density Functional Theory (DFT) single-point calculation at the...

journal_title：Chirality

authors： Arsad SR,Maarof H,Wan Ibrahim WA,Aboul-Enein HY

更新日期：2016-03-01 00:00:00

abstract：:Integrating spheres are widely used with UV-Vis and occasionally with infrared spectrophotometers to measure different types of samples, either in transmission mode (scattered transmission accessories) or in total/diffuse reflectance mode. We built a prototype sphere of the demountable type, which fits easily the samp...

journal_title：Chirality

authors： Castiglioni E,Albertini P

更新日期：2000-05-01 00:00:00

abstract：:The application of the Cartesian coordinate tensor transfer (CCT) technique for simulations of the IR absorption and vibrational circular dichroism (VCD) spectra of relatively large nucleic acid fragments is demonstrated on several case studies. The approach is based on direct ab initio calculations of atomic tensors,...

journal_title：Chirality

authors： Andrushchenko V,Bouř P

更新日期：2010-01-01 00:00:00

abstract：:A method is described for the HPLC analysis of oxamniquine enantiomers in liver fraction incubates, using a second-generation alpha 1-acid glycoprotein-based column (Chiral-AGP). Oxamniquine is extracted from the incubation media by liquid-liquid extraction, using diethyl ether. The dried residue is redissolved in elu...

journal_title：Chirality

authors： Noctor TA,Fell AF,Kaye B

更新日期：1990-01-01 00:00:00

abstract：:Hornet silks adopt a variety of morphology such as fibers, sponge, films, and gels depending on the preparation methods. We have studied the conformation change of hornet silk proteins (Vespa mandarina) as regenerated films, using chiroptical spectrophotometer universal chiroptical spectrophotometer 1, which can measu...

journal_title：Chirality

authors： Kuroda R,Kameda T

更新日期：2018-05-01 00:00:00

abstract：:C(25) highly branched isoprenoid (HBI) alkenes are ubiquitous lipids found in geochemical samples around the globe. The origins of these widespread geochemicals are believed to be restricted to a limited number of diatoms, including Haslea ostrearia (and related species), Rhizosolenia setigera, and Pleurosigma interme...

journal_title：Chirality

authors： Belt ST,Allard WG,Johns L,König WA,Massé G,Robert JM,Rowland S

更新日期：2001-08-01 00:00:00

abstract：:A simple high-yield three-steps route to optically active 4-hydroxymethyl-3-(1H-indolyl)oxazolidin-2-ones from (S)-glycidol is described. The key intermediates (R)-oxiran-2-ylmethyl 1H-indol-4/-5-ylcarbamates are obtained in high yields from (S)-glycidol. These are readily transformed to oxazolidin-2-ones, very intere...

journal_title：Chirality

authors： Chiummiento L,Funicello M,Tramutola F

更新日期：2012-04-01 00:00:00

abstract：:A detailed experimental investigation of an aza-Michael reaction of aniline and chalcone is presented. A series of Cinchona alkaloid-derived organocatalysts with different functional groups were prepared and used in the aza-Michael and retro-aza-Michael reaction. There was an interesting finding that a complete revers...

journal_title：Chirality

authors： Cai YF,Li L,Luo MX,Yang KF,Lai GQ,Jiang JX,Xu LW

更新日期：2011-05-01 00:00:00

abstract：:The stability of Chiralpak AD chiral stationary phase under various solvent conditions was investigated. An analytical method for the detection of the presence of solubilized Chiralpak AD coating was developed using CD spectroscopy (CD signal at 245 nm). In addition, NMR analysis of the solubilized polymer revealed a ...

journal_title：Chirality

authors： Welch CJ,Fairchild J,Sajonz P

更新日期：2007-08-01 00:00:00

abstract：:Acyl glucuronides formed from carboxylic acids can undergo hydrolysis, acyl migration, and covalent binding to proteins. In buffers at physiological pH, the degradation of acylglucuronide of a chiral NSAID, carprofen, consisted mainly of acyl migration. Acidic pH reduced hydrolysis and acyl migration, thus stabilizing...

journal_title：Chirality

authors： Georges H,Presle N,Buronfosse T,Fournel-Gigleux S,Netter P,Magdalou J,Lapicque F

更新日期：2000-02-01 00:00:00

abstract：:Enantioseletive toxicities of chiral pesticides have become an environmental concern recently. In this study, we evaluated the enantiomeric separation of salithion on a suite of commercial chiral columns and assessed the toxicity of enantiomers toward butyrylcholinesterase and Daphnia magna. Satisfactory separations o...

journal_title：Chirality

authors： Zhou S,Lin K,Li L,Jin M,Ye J,Liu W

更新日期：2009-11-01 00:00:00

abstract：:Supercritical fluid chromatography (SFC) is already used for enantioseparation in the pharmaceutical industry, but it is rarely used for the separation of chiral pesticides. Comparing with high performence liquid chromatography, SFC uses much more environmnetal friendly and economic mobile phase, supercritical CO2 . I...

journal_title：Chirality

authors： Zhao L,Xie J,Guo F,Liu K

更新日期：2018-05-01 00:00:00

abstract：:The chiral separation by counter-current chromatography has made great progress in the past three decades. It has become increasingly popular in the field of chiral separation, and many applications have been introduced during the last years. This review mainly focuses on the current topics, applications, and trends i...

journal_title：Chirality

authors： Duan WD,Huang XY,Di DL

更新日期：2020-10-01 00:00:00

abstract：:Vitamin E is an essential nutrient of still increasing economic importance. Vitamin E derivatives include many nonracemic chiral compounds whose chirooptical characterization is scarcely described in the literature. We report the CD spectra of delta-tocopherol and its unsaturated analog delta-tocotrienol. TDDFT calcul...

journal_title：Chirality

authors： Mazzini F,Pescitelli G,Di Bari L,Netscher T,Salvadori P

更新日期：2009-01-01 00:00:00

abstract：:Novel chiral diisopropyl spiro bis(isoxazoline) ligands, anti-i-Pr-SPRIX and syn-i-Pr-SPRIX, were designed and synthesized. Their catalytic utility, X-ray crystallographic analyses, and complexation studies demonstrated the structural features of tetraisopropyl spiro bis(isoxazoline) ligand, i-Pr-SPRIX, which is a pro...

journal_title：Chirality

authors： Takenaka K,Lin X,Takizawa S,Sasai H

更新日期：2015-08-01 00:00:00

abstract：:Enantioselective catalytic epoxidation of olefins is an important problem from both practical and mechanistic points of view. The origins of chiral induction by asymmetric porphyrin and salen complexes were investigated by FT-NMR T1 relaxation techniques. A new chiral vaulted porphyrin (1) that carries (S)-binaphthyl-...

journal_title：Chirality

authors： Groves JT,Crowley SJ,Shalyaev KV

更新日期：1998-01-01 00:00:00

abstract：:Chirality is often glossed over in theoretical or experimental discussions concerning the origin of life, but the ubiquity of homochiral building blocks in known biological systems demands explanation. Information theory can provide a quantitative framework for understanding the role of chirality in biology. Here I sh...

journal_title：Chirality

authors： Carroll JD

更新日期：2009-03-01 00:00:00

abstract：:Gold particles covered with 1,1'-binaphthyl-2,2'-dithiol (BINAS) were prepared. Using size exclusion chromatography, it was possible for the first time to separate the sample into fractions with different sizes and colors. Transmission electron microscopy shows that the particles are very small, in the order of 1 nm o...

journal_title：Chirality

authors： Gautier C,Taras R,Gladiali S,Bürgi T

更新日期：2008-03-01 00:00:00

abstract：:Ion channels are pharmacologic receptors and as such exhibit stereoselective interactions with drugs. Ion channels are conformationally mobile transmembrane proteins existing in a number of open and closed states. Drug interactions with these different states may differ quantitatively and qualitatively. Stereoselectiv...

journal_title：Chirality

authors： Triggle DJ

更新日期：1996-01-01 00:00:00

abstract：:Symmetry breaking by photons, electrons, and molecular interactions lies at the heart of many important problems as varied as the origin of homochiral life to enantioselective drug production. Herein we report a system in which symmetry breaking can be induced and measured in situ at the single-molecule level using sc...

journal_title：Chirality

authors： Tierney HL,Jewell AD,Baber AE,Iski EV,Sykes EC

更新日期：2012-12-01 00:00:00

abstract：:Four Ala-Ala dipeptides with a perfluoroalkyl chain at the N-terminal were synthesized. They were able to self-assemble into helical nanofibers and/or twisted nanobelts in a mixture of DMSO/H2 O. The handedness of nanofibers and nanobelts was controlled by the chirality of the alanine at the N-terminal. The stacking h...

journal_title：Chirality

authors： Zhang L,Lin S,Tong Q,Li Y,Wang Y,Li Y,Li B,Yang Y

更新日期：2019-11-01 00:00:00

abstract：:In this research, 10 chiral pesticides in fruits and vegetables were simultaneously determined using chiral liquid chromatography triple quadrupole-linear ion trap hybrid mass spectrometry (LC-QqLIT). The QuEChERS method was applied for sample preparation, and an enhanced product ion (EPI) scan was used to acquire tan...

journal_title：Chirality

authors： He Z,Peng Y,Wang L,Luo M,Liu X

更新日期：2015-12-01 00:00:00

abstract：:A comparison of the enantiomeric resolution of (+/-)-threo-methylphenidate (MPH) (Ritalin) was achieved on different polysaccharide based chiral stationary phases. The mobile phase used was hexane-ethanol-methanol-trifluoroacetic acid (480:9.75:9.75:0.5, v/v/v/v). Benzoic acid and phenol were used as the mobile phase ...

journal_title：Chirality

authors： Aboul-Enein HY,Ali I

更新日期：2002-01-01 00:00:00

abstract：:Antimalarial drugs have shown potential in suppressing the role of glycosaminoglycans (GAGs) in the pathology of prion protein conformational disorders (e.g. "Mad Cow" disease) by competing for sites of electrostatic interaction. In this study, circular dichroism (CD) and UV/Visible (UV/Vis) absorption spectroscopy te...

journal_title：Chirality

authors： Stanley FE,Warner AM,McWilliams KM,Stalcup AM

更新日期：2011-01-01 00:00:00

abstract：:The stereochemistry of tolperisone, a chiral aryl-alkyl basic ketone was investigated by means of circular dichroism (CD) and ultraviolet (UV) spectroscopy. The unusually high optical activity of tolperisone hydrochloride in the n-->pi* region is interpreted by the presence of a chiral conformer in solution. For stere...

journal_title：Chirality

authors： Zsila F,Hollósi M,Gergely A

更新日期：2000-11-01 00:00:00

abstract：:Planar 2(5H)-furanones substituted at C4 with a chiral pyrrolidinyl group show CD spectra which are apparently due to the distortion of the C4-N1 bond of sp2 character from the plane defined by the 2(5H)-furanone ring atoms and/or due to the presence of substituents in the pyrrolidine ring. This is a new, previously n...

journal_title：Chirality

authors： Gawroński J,Gawrońska K,Kwit M,Kacprzak K,Rychlewska U

更新日期：2004-08-01 00:00:00

abstract：:The application of Chiral Technology, or the (extensive) use of techniques or tools for the determination of absolute stereochemistry and the enantiomeric or chiral separation of racemic small molecule potential lead compounds, has been critical to successfully discovering and developing chiral drugs in the pharmaceut...

journal_title：Chirality

authors： McConnell O,Bach A 2nd,Balibar C,Byrne N,Cai Y,Carter G,Chlenov M,Di L,Fan K,Goljer I,He Y,Herold D,Kagan M,Kerns E,Koehn F,Kraml C,Marathias V,Marquez B,McDonald L,Nogle L,Petucci C,Schlingmann G,Tawa G,Tis

更新日期：2007-09-01 00:00:00

abstract：:In the presence of tridentate chiral ligand 4e, 99% e.e. value was obtained by asymmetric reduction of ethyl benzoylacetate with borane in toluene at 25 degrees C. Various ligands and reaction conditions were investigated to develop a reasonable mechanism that explains the experimental outcomes. ...

journal_title：Chirality

authors： Lee DS

更新日期：2007-02-01 00:00:00

abstract：:Chiral sulfoxides/N-oxides (R)-1 and (R,R)-2 are effective chiral promoters in the enantioselective allylation of α-keto ester N-benzoylhydrazone derivatives 3a-g to generate the corresponding N-benzoylhydrazine derivatives 4a-g, with enantiomeric excesses as high as 98%. Representative hydrazine derivatives 4a-b were...

journal_title：Chirality

authors： Reyes-Rangel G,Bandala Y,García-Flores F,Juaristi E

更新日期：2013-09-01 00:00:00