Investigation of the stability of Chiralpak AD chiral stationary phase under various solvent conditions and development of a method to identify stationary phase-derived polymer contamination.

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：:Spontaneous symmetry breaking in reactive systems, known as a rare physical phenomenon and for the Soai autocatalytic irreversible reaction, might in principle also occur in other, more common asymmetric reactions when the chiral product is capable to promote its formation and an element of "nonlinearity" is involved ...

journal_title：Chirality

authors： Mauksch M,Tsogoeva SB,Wei S,Martynova IM

更新日期：2007-11-01 00:00:00

abstract：:Chiroptical materials have received much attention in diverse fields for applications such as displays, sensors, smart memory devices, and catalysis. Here, we develop a simple fabrication method for polymer films with tunable chiroptical properties using small amounts of self-assembling fluorescent dye as an additive....

journal_title：Chirality

authors： Jintoku H,Ihara H

更新日期：2020-05-01 00:00:00

abstract：:Stereoselectivity in the renal secretion of carbenicillin (CBPC) was studied in rabbits. Significant renal secretion of CBPC was observed in vivo, with the secretion of the S-epimer being greater than that of the R-epimer. Stereoselective transport of CBPC was further studied in vitro using basolateral and brush borde...

journal_title：Chirality

authors： Itoh T,Nakaura H,Koyano S,Tsuda Y,Yamada H

更新日期：1998-01-01 00:00:00

abstract：:High-performance liquid chromatography (HPLC) is a powerful method in the area of chiral separation. In this study, a method of HPLC using carboxymethyl-β-cyclodextrin (CM-β-CD) as chiral selector was developed for enantioseparation of nine indanone and tetralone derivatives. The separation was performed on a conventi...

journal_title：Chirality

authors： Hu X,Guo X,Sun S,Zhu B,Yu J,Guo X

更新日期：2017-01-01 00:00:00

abstract：:The enantiomerization and enantioselective bioaccumulation of metalaxyl by a single dose of exposure to Tenebrio molitor larvae under laboratory condition were studied by high-performance liquid chromatography tandem mass spectroscopy (HPLC-MS/MS) based on a ChiralcelOD-3R [cellulosetris-tris-(3, 5-dichlorophenyl-carb...

journal_title：Chirality

authors： Gao Y,Wang H,Qin F,Xu P,Lv X,Li J,Guo B

更新日期：2014-02-01 00:00:00

abstract：:The separation methods of the enantiomers of two β-blockers and tryptophan were studied using capillary electrochromatography with heparin covalently as well as non-covalently, bonded onto the capillary inner wall as stationary phase and electrokinetic chromatography with heparin as pseudostationary phase. In the case...

journal_title：Chirality

authors： Liu Y,Sombra LL,Stege PW

更新日期：2018-06-25 00:00:00

abstract：:Two new carotenoids, sapotexanthin 5,6-epoxide and sapotexanthin 5,8-epoxide, have been isolated from the ripe fruits of red mamey (Pouteria sapota). Sapotexanthin 5,6-epoxide was also prepared by partial synthesis via epoxidation of sapotexanthin, and the (5R,6S) and (5S,6R) stereoisomers were identified by high-perf...

journal_title：Chirality

authors： Murillo E,Agócs A,Nagy V,Király SB,Kurtán T,Toribio EM,Lakey-Beitia J,Deli J

更新日期：2020-05-01 00:00:00

abstract：:Although the organocatalytic direct asymmetric Michael reactions of carbonyl compounds to nitroalkenes have been investigated intensely, the Michael reaction of the thioether-based donors remains a rather undeveloped field. This work concerns the asymmetric Michael addition of aryl sulfanyl-propan-2-one to nitroalkene...

journal_title：Chirality

authors： Jiang X,Zhang B,Zhang Y,Lin L,Yan W,Wang R

更新日期：2010-07-01 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：:The two enantiomers of N-acyl amide and N-ureide derivatives of 3-amino-5-phenyl-1,4-benzodiazepin-2-ones, which have been known to show anti-respiratory syncytial virus (RSV) activity, were resolved on seven different Pirkle-type chiral stationary phases (CSPs) with the use of 10% isopropyl alcohol in hexane as a mob...

journal_title：Chirality

authors： Park JY,Cho HS,Hyun MH

更新日期：2011-01-01 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

abstract：:3alpha,12alpha-dihydroxy-5beta-cholan-24-oic acid (deoxycholic acid DCA) is able to discriminate between the R- and S-enantiomers of camphorquinone and endo-(+)-3-bromocamphor and select only the S-enantiomers from a racemic mixture. DCA forms novel well ordered 1:1 adducts with (1S)-(+)-camphorquinone and (1S)-endo-(...

journal_title：Chirality

authors： Tahir MI,Rees NH,Heyes SJ,Cowley AR,Prout K

更新日期：2008-07-01 00:00:00

abstract：:One of the most powerful techniques that are currently available to measure thermodynamic parameters such as enthalpy (ΔH), Gibbs free energy (ΔG), entropy changes (ΔS), and binding affinity in chemical reactions is isothermal titration calorimetry (ITC). Recent advances in instrumentation have facilitated the develop...

journal_title：Chirality

authors： Werber L,Mastai Y

更新日期：2018-05-01 00:00:00

abstract：:Two diastereomeric cationic surfactants derived from L-proline, in which the second chiral center is a quaternary nitrogen, have been separated and fully characterized. The recognition properties of the aggregates formed by the two diastereomeric surfactants have been investigated by circular dichroism and (1)H NMR th...

journal_title：Chirality

authors： Borocci S,Ceccacci F,Galantini L,Mancini G,Monti D,Scipioni A,Venanzi M

更新日期：2003-05-15 00:00:00

abstract：:Bis(diamido)-bridged basket resorcin[4]arene (all-S)-1 and its (all-R)-1 enantiomer proved able to interact with 2'-deoxycytidine (2) and pyrimidine nucleoside analogs in dimethyl sulfoxide (DMSO) solution. In such a solvent, the resorcinarene hosts adopt a preferential 1,3-alternate-like conformation, with a larger c...

journal_title：Chirality

authors： D'Acquarica I,Calcaterra A,Sacco F,Balzano F,Aiello F,Tafi A,Pesci N,Uccello-Barretta G,Botta B

更新日期：2013-12-01 00:00:00

abstract：:Metoprolol is available for clinical use as a racemic mixture. The S-(-)-metoprolol enantiomer is the one expressing higher activity in the blockade of the β(1)-adrenergic receptor. The α-hydroxymetoprolol metabolite also has activity in the blockade of the β(1)-adrenergic receptor. The present study describes the dev...

journal_title：Chirality

authors： Antunes Nde J,Cavalli RC,Marques MP,Lanchote VL

更新日期：2013-01-01 00:00:00

abstract：:About 30% of a chemically diverse set of compounds were found to separate on four polysaccharide chiral stationary phases using polar organic mobile phases. No structural features appeared to correlate to successful separations. Titrations between normal and polar organic mobile phases suggested that separation mechan...

journal_title：Chirality

authors： Lynam KG,Stringham RW

更新日期：2006-01-01 00:00:00

abstract：:The opening of ortho-substituted phenyl oxiranes by borohydrides is described both in aqueous and solid phases. Some remarkable differences in the regioselectivity and inversion of enantioselectivity of oxirane ring-opening are reported. The results obtained are compared with previous studies and have allowed some fac...

journal_title：Chirality

authors： Doussot J,Guy A,Siaugue JM,Ferroud C,Guieres AF

更新日期：1999-01-01 00:00:00

abstract：:Despite the fact that several studies have reported the concentrations of various free amino acids in tobacco, their enantiomeric composition is unknown. Both the absolute and enantiomeric compositions of proline, alanine, asparagine, aspartic acid, valine, methionine, leucine,and phenylalanine were determined for thr...

journal_title：Chirality

authors： Kullman JP,Chen X,Armstrong DW

更新日期：1999-01-01 00:00:00

abstract：:Three aldohexoses, glucose, galactose, and mannose, and three aldopentoses, arabinose, xylose, and ribose, were derivatized with L-tryptophanamide (L-TrpNH2 ) under alkaline conditions. Using a basic mobile phase (pH 9.2), the three aldohexoses or the three aldopentoses were simultaneously enantioseparated, respective...

journal_title：Chirality

authors： Shou M,Terashima H,Aizawa S,Taga A,Yamamoto A,Kodama S

更新日期：2015-07-01 00:00:00

abstract：:The use of stereodynamic probes is becoming one of the leading strategies for the fast and effective determination of enantiomeric excess. Recently, we reported a series of novel molecular architectures based on a modified tris(2-pyridylmethyl)amine complex (TPMA), which are able to amplify the electronic CD, in the c...

journal_title：Chirality

authors： Carmo Dos Santos NA,Badetti E,Licini G,Abbate S,Longhi G,Zonta C

更新日期：2018-01-01 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：:Doping nematic liquid crystals with nonracemic chiral compounds induces a twisted nematic (cholesteric) phase. The ability of solutes to twist the nematic phase may be related to the overall shape of the chiral dopant and consequently to its absolute configuration. The cholesteric induction is therefore a powerful too...

journal_title：Chirality

authors： Pieraccini S,Ferrarini A,Spada GP

更新日期：2008-05-15 00:00:00

abstract：:The versatility of a previously developed method for the synthesis of chiral carbene-based palladacycles is demonstrated through the synthesis of two new chiral pyridine-functionalized N-heterocyclic carbene palladacycles with different wingtip groups. The efficiency in their resolution with different counter anions a...

journal_title：Chirality

authors： Ng KH,Li Y,Tan WX,Chiang M,Pullarkat SA

更新日期：2013-03-01 00:00:00

abstract：:According to the Ibuprofen Product-Specific Bioequivalence Guidance of the European Medicines Agency, achiral bioanalytical methods are considered acceptable for demonstration of bioequivalence of ibuprofen-containing products. The aim of this investigation is to compare the bioequivalence outcomes obtained with indiv...

journal_title：Chirality

authors： González-Rojano E,Marcotegui J,Laredo L,Gwaza L,Gordon J,Portolés A,Vargas E,Morales-Alcelay S,García-Arieta A

更新日期：2020-09-01 00:00:00

abstract：:Nine patients taking oral doses of 10 mg/12 h rac-pindolol as part of their treatment for hypertension in pregnancy were recruited for the study. Maternal and fetal gestational age ranged from 20-38 years and 28-41 weeks, respectively. Blood was collected from the umbilical cord vein and from the mother from zero to 1...

journal_title：Chirality

authors： Gonçalves PV,Matthes Ado C,Da Cunha SP,Lanchote VL

更新日期：2002-08-01 00:00:00

abstract：:(R,R)-formoterol was synthesized in seven steps with 4-hydroxyl-3-nitro-acetophenone as the starting material. The key intermediate, the chiral secondary alcohol 4, was prepared via Rh-catalyzed asymmetric transfer hydrogenation with (S,S)-PEGBsDPEN as the ligand and sodium formate as the hydrogen donor under mild con...

journal_title：Chirality

authors： Huang L,Liu J,Shan W,Liu B,Shi A,Li X

更新日期：2010-02-01 00:00:00

abstract：:Three chiral derivatives of the alkaloid sparteine (bispidines), characterized by the 3,7-diazabicyclo[3.3.1]nonane moiety, were designed as efficient ligands in a number of enantioselective reactions due to their metal coordination properties. A full evaluation of the 3D properties of the compounds was carried out, a...

journal_title：Chirality

authors： Castellano C,Sacchetti A,Meneghetti F

更新日期：2016-04-01 00:00:00

abstract：:(3SR,4RS)-3,4-Epoxypiperidine-4-carboxylic acid (isoguvacine oxide) is a potent and specific GABAA receptor agonist. Isoguvacine oxide, originally designed as a potentially alkylating agonist, turned out to interact with the GABAA receptor in a fully reversible manner. The protected form of isoguvacine oxide, benzyl (...

journal_title：Chirality

authors： Frølund B,Jeppesen L,Krogsgaard-Larsen P,Hansen JJ

更新日期：1995-01-01 00:00:00