Solid-state circular dichroism and hydrogen bonding, part 2: the case of hypothemycin re-investigated.

abstract：:This article describes a very useful extension of an unique column switching technique called "Simulated Moving Columns" (SMC) that was previously reported for chiral high performance liquid chromatography (HPLC) (Zhang and McConnell, Journal of Chromatography A 2004;1028:227-238). SMC uses two or three short chiral c...

journal_title：Chirality

authors： Zhang Y,Dai J,Wang-Iverson DB,Tymiak AA

更新日期：2007-09-01 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 aim of this work was to establish structure-reactivity relationships between chiral aggregates (micelles, vesicles, and "pseudo-micelles" of amphiphilic dendrimers) and asymmetric induction. In water, micelles or vesicles formed with sugar-headed surfactants gave less than 10% ee in the reduction of prochiral keto...

journal_title：Chirality

authors： Rico-Lattes I I,Schmitzer A,Perez E,Lattes A

更新日期：2001-01-01 00:00:00

abstract：:The chiral recognition ability and solvent versatility of a new chiral stationary phase containing amylose 3,5-dimethylphenylcarabamate immobilized onto silica gel (CHIRALPAK IA) is investigated. Thus, the direct enantioselective separation of a set of racemic N-alkylated barbiturates and 3-alkylated analogs of thalid...

journal_title：Chirality

authors： Ghanem A,Al-Humaidi E

更新日期：2007-06-01 00:00:00

abstract：:In this work, we study the effect of different variables affecting elution profile distortion on the enantiomeric resolution eventually achievable when working with on-line coupled liquid chromatography to gas chromatography (LC-GC). Specifically, the proposed configuration combines achiral reversed-phase liquid chrom...

journal_title：Chirality

authors： Martínez RM,Barba C,Robredo S,Herraiz M

更新日期：2019-10-01 00:00:00

abstract：:Flurbiprofen is a kind of nonsteroidal anti-inflammatory drug, which has been widely used in clinic for treatment of rheumatoid arthritis and osteoarthritis. It has been reported that S-flurbiprofen shows good performance on clinic anti-inflammatory treatment, while R-enantiomer almost has no pharmacological activitie...

journal_title：Chirality

authors： Cui X,Ding Q,Shan RN,He CH,Wu KJ

更新日期：2019-06-01 00:00:00

abstract：:Numbers of resolving factors were investigated to improve resolution of venlafaxine 1. An effective resolving agent, O,O'-di-p-toluoyl-(R, R)-tartaric acid 2, was screened using similar method of 'Dutch resolution' from tartaric acid derivatives. The resolution efficiency was up to 88.4%, when the ratio of rac-1 and 2...

journal_title：Chirality

authors： Liu ZJ,Liu H,Chen XW,Lin M,Hu Y,Tuo X,Yuan ZY,Sun XX

更新日期：2018-03-01 00:00:00

abstract：:Chiral pesticides currently constitute about 50% of all pesticides dosage used in China, and this ratio is increasing as more complex structures are introduced. Dichlorprop methyl (DCPPM) is a chiral herbicide consisting of a pair of enantiomers. In this study, the enantiomeric separation of DCPPM was investigated by ...

journal_title：Chirality

authors： Ma Y,Xu C,Wen Y,Liu W

更新日期：2009-04-01 00:00:00

abstract：:The enantioselective hydrogenation of methyl or ethyl pyruvate over cinchona-platinum catalyst system (Orito's reaction) is one of the most intensively studied heterogeneous catalytic asymmetric hydrogenation reactions. Studies aiming at systematic changes of the chiral template have played a crucial role in creating ...

journal_title：Chirality

authors： Tálas E,Margitfalvi JL

更新日期：2010-01-01 00:00:00

abstract：:A simple, green, and direct three-component condensation of acetophenone, aromatic aldehydes with 3-oxo-N-phenylbutanamide (acetoacetanilide) to generate some novel (1S,6R)/(1R,6S)-2-oxo-N,4,6-triarylcyclohex-3-enecarboxamide derivatives was carried out over K2 CO3 (10 mol%) with high efficiency in water/ethanol as gr...

journal_title：Chirality

authors： Mousavi SR

更新日期：2016-11-01 00:00:00

abstract：:Several in vivo and in vitro studies on the stereoselective potency of isoflurane enantiomers suggest beneficial effects of the (+)-(S)-enantiomer. In order to detect possible differences in the pharmacokinetics of isoflurane enantiomers, a clinical study of 41 patients undergoing general anesthesia maintained with ra...

journal_title：Chirality

authors： Schmidt R,Wahl HG,Häberle H,Dieterich HJ,Schurig V

更新日期：1999-01-01 00:00:00

abstract：:The gem-disubstituted cyclotriphosphazene 1 reacted with piperazine (pip) to give the piperazine-bridged derivative 2, which is expected to exist in meso and racemic forms because the two PCl (pip) groups are stereogenic. The proton-decoupled (31)P NMR spectrum of 2 gave rise to two similar sets of ABX signals in a 1:...

journal_title：Chirality

authors： Bui TT,Coles SJ,Davies DB,Drake AF,Eaton RJ,Hursthouse MB,Kiliç A,Shaw RA,Yeşilot S

更新日期：2005-10-01 00:00:00

abstract：:The measurement of optical rotation (OR) and optical rotatory dispersion has been finding renewed interest for some years, because of advancement in computational methods and in the performance of new experiments. Here, we shortly review the traditional and most-used experimental methods. We define and discuss the two...

journal_title：Chirality

authors： Castiglioni E,Abbate S,Longhi G

更新日期：2011-10-01 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：: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：:The present work firstly described the enantioseparation and determination of flumequine enantiomers in milk, yogurt, chicken, beef, egg, and honey samples by chiral liquid chromatography-tandem mass spectrometry. The enantioseparation was performed under reversed-phase conditions on a Chiralpak IC column at 20°C. The...

journal_title：Chirality

authors： Li S,Liu B,Xue M,Yu J,Guo X

更新日期：2019-11-01 00:00:00

abstract：:Studies of xenobiotic disposition in rodents often employ experimental designs using differing routes of administration. In an effort to investigate the effects of route of administration on enantioselective disposition of xenobiotics, a chiral polychlorinated biphenyl (PCB), racemic PCB 136, was administered as a sin...

journal_title：Chirality

authors： Kania-Korwel I,Shaikh NS,Hornbuckle KC,Robertson LW,Lehmler HJ

更新日期：2007-01-01 00:00:00

abstract：:A summary of selected NMR studies of enantiodiscrimination phenomena regarding the use of quinine-based chiral solvating agents (CSAs) for the determination of the enantiomeric compositions in solution is reported, with explanations of their multireceptorial character offered. ...

journal_title：Chirality

authors： Uccello-Barretta G,Balzano F,Salvadori P

更新日期：2005-01-01 00:00:00

abstract：:Several biologically active compounds structurally include the enantiopure 2-substituted-1,4-benzodioxane scaffold. The straightforward racemization that affects reactions involving most of the common chemical reactives is thus a crucial issue. The developing of a completely stereo-controlled synthetic route that does...

journal_title：Chirality

authors： Straniero V,Casiraghi A,Fumagalli L,Valoti E

更新日期：2018-07-01 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：: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：: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：: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：: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：:Nine β-aminoketones were synthesized via Mannich reaction when benzaldehyde was condensed with some primary amines and acetophenone. The purified compounds were identified by using spectroscopic methods. The enantiomeric separation of these derivatives was carried out by high-performance liquid chromatography (HPLC) u...

journal_title：Chirality

authors： Addadi K,Sekkoum K,Belboukhari N,Cheriti A,Aboul-Enein HY

更新日期：2015-05-01 00:00:00

abstract：:The adsorption of heptahelicene, a helically shaped polyaromatic hydrocarbon (C(30)H(18)), on a Cu(111) surface was studied by means of thermal desorption mass spectrometry (TDMS) and low energy electron diffraction (LEED) at temperatures between 130-1,000 K under ultrahigh vacuum (UHV) conditions. The molecule in the...

journal_title：Chirality

authors： Ernst KH,Kuster Y,Fasel R,Müller M,Ellerbeck U

更新日期：2001-01-01 00:00:00

abstract：:In order to investigate the chiral benzedrine molecules corresponding to their different characteristics in biochemical systems, we studied their interaction with D3 R using the docking method, molecular dynamic simulation, and quantum chemistry. The obtained results indicate that the active residues for R-benzedrine ...

journal_title：Chirality

authors： Wang M,Xie W,Li A,Xu S

更新日期：2016-10-01 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：:A new colorimetric chiral sensor material consisting of three different functional sites such as chromophore (2,4-dinitrophenylazophenol dye), binding site (crown ether), and chiral barrier (3,3'-diphenyl-1,1'-binaphthyl group) was prepared and applied to the recognition of the two enantiomers of primary amino alcohol...

journal_title：Chirality

authors： Cho EN,Li Y,Kim HJ,Hyun MH

更新日期：2011-04-01 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