Determination of enantiomeric excess of ethyl 3,5-dihydroxy-6-benzyloxy hexanoate by chiral reverse phase high performance liquid chromatography.

abstract：:Three β-keto sulfoxides (1-3) were synthesized in enantiopure form and investigated by means of circular dichroism (CD) spectroscopy, both in electronic and vibrational range (ECD, VCD), in combination with quantum chemical calculations. For compound 2, the X-ray structure was available; thus, the ECD in the solid sta...

journal_title：Chirality

authors： Górecki M,Capozzi MAM,Albano G,Cardellicchio C,Di Bari L,Pescitelli G

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：: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：:Bath salts, fumigations, cleaners and air fresheners, behind these terms substances are hidden, which count as "Legal Highs". These fancy names are used to pretend Legal Highs as harmless compounds, to circumvent legal regulations for marketing as well as to increase the sales. Besides classic illicit drugs of synthet...

journal_title：Chirality

authors： Kadkhodaei K,Kadisch M,Schmid MG

更新日期：2020-01-01 00:00:00

abstract：:Growing attention in developing new N-heterocyclic carbene (NHC)-mediated reactions involving homoenolate intermediates has prompted our interest in exploring the mechanistic details of the related reactions. In this work, we carried out a detailed theoretical study for the NHC-catalyzed annulation reaction of cinnama...

journal_title：Chirality

authors： Sun H,Fang X,Chi YR,Li G

更新日期：2013-09-01 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：:Herein we report CD spectroscopic studies on complexes of (R,R)-dimethyl-, (R,R)-diisobutyl-, and (S,S)-di-sec-butyl-phenazino-18-crown-6 ligands (Scheme 1) with selected alkali (Na+, K+), alkaline earth (Mg2+, Ca2+), and transition-metal (Ag+, Zn2+, Ni2+, Cd2+, Pb2+) cations. The complexation was monitored in the 300...

journal_title：Chirality

authors： Szarvas S,Szalay L,Vass E,Hollósi M,Samu E,Huszthy P

更新日期：2005-06-01 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

abstract：:Diamino carboxylic acids have recently come to the attention of scientists working in the field of early life and its development. These are the monomers of a hypothetic early form of genetic material, the so-called Peptide Nucleic Acid (PNA) (Nielson et al., Proc Natl Acad Sci USA 2000;97:3868-3871). Since all biopol...

journal_title：Chirality

authors： Bredehöft JH,Breme K,Meierhenrich UJ,Hoffmann SV,Thiemann WH

更新日期：2007-07-01 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：:Homoprolinol analogs, a class of optically active γ-amino alcohols, were examined systematically in the enantioselective addition reactions of diethylzinc to aldehydes. By comparison of the results catalyzed by these γ-amino alcohols with those by the β-amino alcohols based on pyrrolidine architecture reported in the ...

journal_title：Chirality

authors： Liu CL,Wei CY,Wang SW,Peng YG

更新日期：2011-11-01 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：:A statement has been formulated that chirality is an indispensable inherent property of all material objects, at one level of organization of matter or another. The translation of chirality from one level of material objects to another deserves our attention. The parity violation of weak interactions can be discussed ...

journal_title：Chirality

authors： Davankov V

更新日期：2006-08-01 00:00:00

abstract：:Chiral natural flavor compounds exhibit characteristic enantiomeric excesses due to stereoselective, enzymatically catalyzed reactions during biogenesis. Although the enzymatic formation of the strawberry key flavor compound 4-hydroxy-2,5-dimethyl-3(2H)-furanone (HDMF; Furaneol(R)) is anticipated, the naturally occurr...

journal_title：Chirality

authors： Raab T,Hauck T,Knecht A,Schmitt U,Holzgrabe U,Schwab W

更新日期：2003-08-01 00:00:00

abstract：:2-Alkenyl- and 2-vinyl-5-pyrimidyl alkanols are highly enantioselective asymmetric autocatalysts with significant amplification of enantiomeric excess in the enantioselective addition of diisopropylzinc to 2-alkenyl- and 2-vinylpyrimidine-5-carbaldehydes. Consecutive asymmetric autocatalysis starting from 7% ee increa...

journal_title：Chirality

authors： Sato I,Yanagi T,Soai K

更新日期：2002-02-01 00:00:00

abstract：:Cyclic triamides bearing amidino groups at the meta position of the phenyl rings were synthesized, and their conformational properties in the crystal and in solution were examined. Compound exists as a capsule-type dimer of the enantiomers with a bowl-shaped syn conformation in the crystal state. Compound exists mainl...

journal_title：Chirality

authors： Nishiyama S,Urushibara K,Masu H,Azumaya I,Kagechika H,Tanatani A

更新日期：2015-08-01 00:00:00

abstract：:Experimental hyperlipidemia has shown to decrease cytochrome P450 3A4 and 2C11 expression and to increase liver concentrations and the plasma protein binding of halofantrine (HF) enantiomers. The present study examined the effect of hyperlipidemic (HL) serum on the metabolism of HF enantiomers by primary rat hepatocyt...

journal_title：Chirality

authors： Patel JP,Hamdy DA,El-Kadi AO,Brocks DR

更新日期：2012-07-01 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：:An increase in both retention and enantioselectivity for some beta-blocking agents was observed when exchanging potassium to sodium ion in the buffer used as mobile phase. A large effect of ionic strength on retention was observed, while the enantioselectivity was constant. ...

journal_title：Chirality

authors： Hedeland M,Jönsson S,Isaksson R,Pettersson C

更新日期：1998-01-01 00:00:00

abstract：:Caffeic acid-derived polyethers are a class of natural products isolated from the root extracts of comfrey and bugloss, which are endowed with intriguing pharmacological properties as anticancer agents. The synthesis of new polyether derivatives is achieved through ring-opening polymerization of chiral 2,3-disubstitut...

journal_title：Chirality

authors： Tedesco D,Fabini E,Barbakadze V,Merlani M,Zanasi R,Chankvetadze B,Bertucci C

更新日期：2015-12-01 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：:Six secondary phosphine oxides and their tautomeric equilibria as free ligands and in the presence of an equimolar amount of the chiral dirhodium complex Rh* are described and discussed. Discrimination of enantiomers is easily possible by inspecting the (31)P NMR resonances; some (1)H and (13)C NMR resonances are usef...

journal_title：Chirality

authors： Magiera D,Szmigielska A,Pietrusiewicz KM,Duddeck H

更新日期：2004-01-01 00:00:00

abstract：:Achiral 4-isopropyltropolone methyl ether (3) included in an optically active host compound (-)-1 yielded optically active photocyclization products (-)-5 and (-)-6 in 96 and 90% ee, respectively, upon photoirradiation in the solid state. ...

journal_title：Chirality

authors： Tanaka K,Nagahiro R,Urbanczyk-Lipkowska Z

更新日期：2002-07-01 00:00:00

abstract：:rac-Isradipine is a dihydropyridine type calcium antagonist. Its calcium entry blocking effect is due primarily to the (+)-(S)-enantiomer. This study describes a sensitive enantioselective method for the determination of isradipine in human serum. Following alkaline extraction into hexane, the enantiomers of isradipin...

journal_title：Chirality

authors： Rask HS,Angelo HR,Christensen HR

更新日期：1998-01-01 00:00:00

abstract：:A chiral alkylglucoside surfactant, namely n-octyl-beta-D-maltopyranoside (OM), was evaluated in the enantiomeric separation of phenoxy acid herbicides. The enantiomeric resolution of the phenoxy acid herbicides could be manipulated readily by adjusting the surfactant concentration, ionic strength, pH, the percent org...

journal_title：Chirality

authors： Mechref Y,el Rassi Z

更新日期：1996-01-01 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：: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：:A three-dimensional molecularly imprinted overoxidized polypyrrole/MnO2 /carbon felt (MIOPPy/MnO2 /CF) composites were fabricated, which results in increased active area of the surface of the molecularly imprinted polymers film and greatly improved electrochemical chiral recognition effect for tryptophan isomers. The ...

journal_title：Chirality

authors： Dong L,Liu X,Xu H,Wu D,Gao S,Zhong L,Kong Y

更新日期：2019-11-01 00:00:00

abstract：:The optical rotation sign/absolute configuration relationships of several alpha-methyl-alpha-arylglycines have been reinvestigated by crystallographic methods, as they have been found to be inconsistent in recent literature. Assignments previously made by enzymatic resolution, by analogy with natural tertiary aminoaci...

journal_title：Chirality

authors： Ferron L,Guillen F,Coste S,Coquerel G,Plaquevent JC

更新日期：2006-08-01 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