Substituent effects in the selective reductive opening of epoxides with borohydrides in the presence of beta-cyclodextrin

abstract：:A simple and reliable chiral HPLC method was developed for the determination of enantiomeric excess of a chiral dihydroxy intermediate for the chemoenzymatic synthesis of side chain of statin drugs. After evaluating different columns and conditions, the four stereoisomers of ethyl 3,5-dihydroxy-6-benzyloxy hexanoate w...

journal_title：Chirality

authors： Liu JH,Yu BY,Chen YJ

更新日期：2008-01-01 00:00:00

abstract：:The effects of temperature on the chiral recognition of cyclic β-amino acid enantiomers on zwitterionic [Chiralpak ZWIX(+) and ZWIX(-)] chiral stationary phases were investigated. Experiments were performed at different mobile phase compositions and under 10°C column temperature increments in the temperature range 10-...

journal_title：Chirality

authors： Ilisz I,Pataj Z,Gecse Z,Szakonyi Z,Fülöp F,Lindner W,Péter A

更新日期：2014-08-01 00:00:00

abstract：:The direct asymmetric aldol reactions of equivalent molar amounts of aldehydes and ketones were carried out at -20 degrees C over alkaline Al(2)O(3) with 20 mol % of Pro-Trp as catalyst and 20 mol % of N-methylmorpholine or 1,4-diazabicyclo[2.2.2]octane as additive. After simple and environmentally friendly work-up, m...

journal_title：Chirality

authors： Lei M,Xia S,Wang J,Ge Z,Cheng T,Li R

更新日期：2010-06-01 00:00:00

abstract：:Chiral molecules can either be handed (i.e., "shoes") or nonhanded ("potatoes"). The only chiral ligand partition for tetrahedral metal complexes (or for a tetrahedral carbon atom such as that found in amino acids and other chiral biological molecules) is the fully unsymmetrical degree 6 partition (1(4)), which leads ...

journal_title：Chirality

authors： King RB

更新日期：2001-08-01 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：: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：:A chiral liquid chromatography/mass spectrometry (LC/MS) bioanalytical procedure has been developed for the analysis of the antimalaric agent Fenozan B07 in dog plasma. Normal-phase chromatography involving a phenylcarbamate derivative of cellulose coated on silica gel as the chiral stationary phase was used to resolv...

journal_title：Chirality

authors： Maraschiello C,Vilageliu J,Dorronsoro I,Martinez A,Floriano P,Gómez-Acebo E

更新日期：2006-05-15 00:00:00

abstract：:The size, sign, and profile of induced circular dichroism (CD) features in the Soret region are reliable indicators of the binding modes of porphyrins and metalloporphyrins to DNA. Porphyrins shown (using such CD criteria) to be intercalators in monodispersed DNA duplexes prove extremely useful for the detection and c...

journal_title：Chirality

authors： Pasternack RF

更新日期：2003-05-05 00:00:00

abstract：:[3β,5β,7α,12α]-3-(4-t-Butylbenzoilamine)-7,12-dihydroxycholan-24-oic acid was synthesized and recrystallized from chlorobenzene and acetone. Orthorhombic P2(1)2(1)2(1) and monoclinic P2(1) crystals were obtained, respectively, and both crystals include solvent and water molecules with a 1:1:1 stoichiometry. In the sec...

journal_title：Chirality

authors： Meijide F,Trillo JV,Soto VH,Jover A,Tato JV

更新日期：2011-11-01 00:00:00

abstract：:Vibrational circular dichroism spectra (VCD) in the mid-IR region and electronic circular dichroism (ECD) spectra for three carnitine derivatives in the form of hydrochloride salts were recorded in deuterated methanol solutions. Density Functional Theory calculations help one to understand the significance of the obse...

journal_title：Chirality

authors： Mazzeo G,Abbate S,Longhi G,Castiglioni E,Villani C

更新日期：2015-12-01 00:00:00

abstract：:In modern chromatography, chiral stationary phase (CSP) and enantiomer self-disproportionation (ESD) are new inventions of packing material offer a guarantee for a successful enantiomeric separation. All CSPs were synthesized by chemical bonding of the relevant organic moieties onto a porous parent silica material for...

journal_title：Chirality

authors： Mayani VJ,Abdi SH,Mayani SV,Kim HC,Park SK

更新日期：2011-04-01 00:00:00

abstract：:New chiral derivatizing reagents (CDAs) derived from trans-1,2-diaminocyclohexane, having an electron-deficient aromatic substituent (either an aromatic imide or 3,5-dinitrobenzamide) and rigid structure (either an amide or a urea linker), are reported. Significant shift differences of diastereotopic protons in the 1H...

journal_title：Chirality

authors： Kaik M,Gajewy J,Grajewski J,Gawronski J

更新日期：2008-03-01 00:00:00

abstract：:This review brings together the past and current methods for synthesizing the classical cucurbit[n]uril (Q[n]), structural variants, and derivatives. Here we refer to the first family of Q[n] as " classical," where the cavity is spheroidal and carry no substituents at any of the equatorial methine carbons or the methy...

journal_title：Chirality

authors： Mandadapu V,Day AI,Ghanem A

更新日期：2014-11-01 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：:Subcellular fractions of three human brain specimens were found to contain esterase activities which hydrolyzed racemic oxazepam 3-acetate (rac-OXA). All three human brain preparations were highly selective toward the S-enantiomer of rac-OXA. ...

journal_title：Chirality

authors： Yang SK,Huang A,Huang JD

更新日期：1993-01-01 00:00:00

abstract：:In this review article we examine state-of-the-art techniques for the structural elucidation of organic compounds isolated from natural sources. In particular, we focus on the determination of absolute configuration (AC), perhaps the most challenging but inevitable step in the whole process, especially when newly isol...

journal_title：Chirality

authors： Pescitelli G,Kurtán T,Flörke U,Krohn K

更新日期：2009-01-01 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：: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 influence of latent heat dissipated by the crystallization of 1,1'-binaphthyl in its supercooled molten state on the chiral symmetry breaking transition was investigated. Temperature change in the crystallization system was monitored by infrared thermocamera. Temperature rise due to the dissipation of latent heat ...

journal_title：Chirality

authors： Asakura K,Hayashi M,Osanai S

更新日期：2003-03-01 00:00:00

abstract：:We demonstrate by using vibrational circular dichroism (VCD) spectroscopy that it is possible to investigate the chirality of a supramolecular polymeric system in relatively dilute solutions. Chiral C(3)-symmetrical discotic molecules, based on a trialkylbenzene-1,3,5-carboxamide, form supramolecular columnar stacks w...

journal_title：Chirality

authors： Smulders MM,Buffeteau T,Cavagnat D,Wolffs M,Schenning AP,Meijer EW

更新日期：2008-09-01 00:00:00

abstract：:In this work, a new capillary electrokinetic chromatography (EKC) approach using ethanediamine-bonded poly (glycidyl methacrylate) (Ami-PGMA) microspheres as pseudostationary phases (PSPs) for enantioseparation with a polysaccharide, chondroitin sulfate E (CSE), as the chiral selector. The CSE@Ami-PGMA EKC system was ...

journal_title：Chirality

authors： Sun X,Yu T,Xu G,Du Y,Chen J,Li X

更新日期：2019-02-01 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：:Rabeprazole is an effective proton pump inhibitor to treat acid-related diseases. To achieve the simultaneous determination of rabeprazole enantiomers in human plasma, a chiral LC-MS/MS method was developed and validated. Acetonitrile including 0.1% ammonium were used as protein precipitating agent. Analytes were sepa...

journal_title：Chirality

authors： Sun LN,Shen YW,Ying YW,Li D,Li TF,Zhang XH,Zhao P,Ding L,Wang YQ

更新日期：2018-12-01 00:00:00

abstract：:In this computational study, we illustrate a method for computing phosphorescence and circularly polarized phosphorescence spectra of molecular systems, which takes into account vibronic effects including both Franck-Condon and Herzberg-Teller contributions. The singlet and triplet states involved in the phosphorescen...

journal_title：Chirality

authors： Egidi F,Fusè M,Baiardi A,Bloino J,Li X,Barone V

更新日期：2018-07-01 00:00:00

abstract：:The biodegradation of the chiral phenoxyalkanoic herbicides 2-(2,4-dichlorophenoxy)propionic aid (2,4-DP) and 2-(4-chloro-2-methylphenoxy)propionic acid (MCPP) was investigated using enantioselective HPLC and chiroptical detection. Racemic mixtures of 2,4-DP and MCPP were applied to three species of turf grass, four s...

journal_title：Chirality

authors： Schneiderheinze JM,Armstrong DW,Berthod A

更新日期：1999-01-01 00:00:00

abstract：:Three N,N-dimethylcarbamyl derivatives of oxazepam (1-(N,N-dimethylcarbamyl)oxazepam, 3-O-(N,N-dimethylcarbamyl)oxazepam, and 1,3-O-bis(N,N-dimethylcarbamyl) oxazepam) and a 3-O-acyl-1-(N,N-dimethylcarbamyl)-oxazepam were synthesized from either oxazepam or demoxepam. Enantiomeric pairs of these derivatives and of cam...

journal_title：Chirality

authors： Yang SK,Lu XL

更新日期：1991-01-01 00:00:00

abstract：:Plasmonic nanoparticles (NPs) adsorbing onto helical bacteria can lead to formation of NP helicoids with micron scale pitch. Associated chiroptical effects can be utilized as bioanalytical tool for bacterial detection and better understanding of the spectral behavior of helical self-assembled structures with different...

journal_title：Chirality

authors： Feng W,Kadiyala U,Yan J,Wang Y,DiRita VJ,VanEpps JS,Kotov NA

更新日期：2020-07-01 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：:An enantioseparation of the antipsychotic drug butaclamol in human plasma by high-performance liquid chromatography (HPLC) with solid phase extraction is presented. The separation was achieved on the vancomycin macrocyclic antibiotic chiral stationary phase (CSP) Chirobiotic V with a polar ionic mobile phase (PIM) con...

journal_title：Chirality

authors： Aboul-Enein HY,Hefnawy MM

更新日期：2004-03-01 00:00:00

abstract：:Previously, a diazaphospholidine has been synthesized and evaluated as a chiral derivatizing reagent for the determination of the optical purity of chiral alcohols via 31P NMR spectroscopy (Alexakis et al., J. Org. Chem. 57:1224-1237, 1992). Our laboratory is interested in the advantageous and practical applications o...

journal_title：Chirality

authors： House KL,O'Connor MJ,Silks LA 3rd,Dunlap RB,Odom JD

更新日期：1994-01-01 00:00:00