Chirality and chiroptical properties of amyloid fibrils.

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：:The objective of this brief highlight is to point out the central role of the exciton chirality method to gain insights on the structural basis of the recently achieved ligand gating of synthetic ion channels. This unprecedented ligand gating was achieved with an equally unprecedented transmembrane rigid-rod pi-stack ...

journal_title：Chirality

authors： Sakai N,Talukdar P,Matile S

更新日期：2006-02-01 00:00:00

abstract：:(S)-(-)-2-(α-hydroxyethyl)-benzimidazole and (S)-(+)-2-(α-hydroxybenzyl)-benzimidazole work as chiral Brønsted bases (BBs) in Diels-Alder reaction between anthrone and maleimides under mild reaction condition. These chiral BBs cause asymmetric induction. ...

journal_title：Chirality

authors： Mirgane NA,Karnik AV

更新日期：2011-05-01 00:00:00

abstract：:6-Fluoro-2-methyl-1,2,3,4-tetrahydroquinoline (FTHQ) enantiomers were separated by supercritical fluid extraction using carbon dioxide. Diastereoisomeric salts were formed from the racemic base with less than one equivalent of O,O'-di-(4-toluoyl)-(2R,3R)-tartaric acid (DPTTA). Further purification was achieved by part...

journal_title：Chirality

authors： Kmecz I,Simándi B,Bálint J,Székely E,Fogassy E,Kemény S

更新日期：2001-01-01 00:00:00

abstract：:A series of silica-supported proline-based peptides were synthesized and applied as catalysts for direct asymmetric intermolecular aldol reactions. Among these, a peptide with two L-proline units was found to be the most efficient one for the asymmetric aldol reactions between acetone and aromatic aldehydes. The react...

journal_title：Chirality

authors： Yan J,Wang L

更新日期：2009-04-01 00:00:00

abstract：:The elusive epimerization process in the chiral butenolide moiety of Annonaceous acetogenins was examined under several sets of conditions commonly used for elimination leading to the alpha, beta-unsaturated lactone and the results provide practical guidance in choosing elimination conditions. ...

journal_title：Chirality

authors： Yu Q,Wu Y,Wu YL,Xia LJ,Tang MH

更新日期：2000-03-01 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：: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：:Parallel kinetic resolution of Evans' phenylglycine derived oxazolidinone using an equimolar combination of quasi-enantiomeric active esters (derived from [D,13C]-labeled 2-phenylpropionic acid) was achieved. The levels of stereocontrol were high, leading to products with predictable configurations. ...

journal_title：Chirality

authors： Coumbarides GS,Dingjan M,Eames J,Flinn A,Northen J

更新日期：2007-05-05 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：:The initial step in the metabolism of dolasetron or MDL 73,147EF [(2 alpha, 6 alpha, 8 alpha, 9a beta)-octahydro-3-oxo-2,6-methano-2H- quinolizin-8-yl 1H-indol-3-carboxylate, monomethanesulfonate] is the reduction of the prochiral carbonyl group to give a chiral secondary alcohol "reduced dolasetron." An HPLC method, ...

journal_title：Chirality

authors： Dow J,Berg C

更新日期：1995-01-01 00:00:00

abstract：:A variety of reactions can be categorized under the global concept of the "interconversion of stereoisomers." Thus, racemization or epimerization can result from inversion of labile chiral centers. From the examples available, some predictive rules are suggested for a chiral center of the type R"R'RC-H undergoing base...

journal_title：Chirality

authors： Testa B,Carrupt PA,Gal J

更新日期：1993-01-01 00:00:00

abstract：:The chiral discrimination ability of two recently prepared chiral stationary phases (CSP 1 and CSP 2), based on a leucine derived chiral selector, was tested for the enantiomers of dihydropyrimidone (DHPM) derivatives and compared with the commercially available Hyun-leucine CSP 3 and classical Pirkle-leucine CSP 4. B...

journal_title：Chirality

authors： Forjan DM,Gazić I,Vinković V

更新日期：2007-06-01 00:00:00

abstract：:Plants and fungi are seemingly inexhaustible sources of interesting natural products with remarkable structural and biological diversity. One of the most important groups is the terpenes, ubiquitous natural products that are generated by 2 now well-established biosynthetic pathways: the older mevalonate and the more r...

journal_title：Chirality

authors： Reveglia P,Cimmino A,Masi M,Nocera P,Berova N,Ellestad G,Evidente A

更新日期：2018-10-01 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：: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 phenomenon of enantioselectivity in the metabolism of mexiletine (MEX) conjugation was investigated in eight female patients with the arrhythmic form of chronic Chagas' heart disease treated with racemic mexiletine hydrochloride (two 100 mg capsules every 8 hr). Blood samples were collected up to 24 hr after the a...

journal_title：Chirality

authors： Lanchote VL,Cesarino EJ,Santos VJ,Mere Júnior Y,Santos SR

更新日期：1999-01-01 00:00:00

abstract：:The prochiral anthelmintic drug albendazole was administered orally to sheep and rats. Blood samples were taken at standardized intervals during the time course of the plasma kinetics: 18 h in rats and 48 h in sheep. The enantiomeric ratio of the sulfoxide metabolite was determined by means of HPLC on a chiral station...

journal_title：Chirality

authors： Delatour P,Benoit E,Caude M,Tambute A

更新日期：1990-01-01 00:00:00

abstract：:In order to get further insight into the mechanism by which bovine serum albumin (BSA) discriminates between enantiomers of organic acids, some radioisotopically labeled, nonaromatic carboxylic acids were studied under varying mobile phase conditions. It was found for a series of N-alkanoyl-DL-[3H]leucines that the D-...

journal_title：Chirality

authors： Allenmark S

更新日期：1993-01-01 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：: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：:A series of representative optically active derivatives of 4-hydroxy-5-alkylcyclopent-2-en-1-one were prepared from the respective 2-furyl methyl carbinols via the Piancatelli rearrangement followed by the enzymatic kinetic resolution of racemates. Applicability of chiroptical methods (experimental and calculated elec...

journal_title：Chirality

authors： Frelek J,Karchier M,Madej D,Michalak K,Różański P,Wicha J

更新日期：2014-06-01 00:00:00

abstract：:The impact of crystalline forces on the solid-state circular dichroism (CD) spectrum of hypothemycin (), a biologically active molecule extracted from natural sources, has been analyzed by means of time-dependent density functional theory CD calculations. Input structures were extracted from the X-ray geometry of and ...

journal_title：Chirality

authors： Pescitelli G

更新日期：2012-09-01 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：:[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：: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：:The possibility that enantiodiscrimination of bilirubin might be involved in neuronal membrane destabilization, and therefore in bilirubin toxicity, was investigated, by circular dichroism, on model membranes composed of phospholipids. The equilibrium between bilirubin enantiomers is displaced at some extent by the in...

journal_title：Chirality

authors： Bernardini C,D'Arrigo P,Elemento G,Mancini G,Servi S,Sorrenti A

更新日期：2009-01-01 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：: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：:The improvement of the biocatalytic reduction of 2-allyl-carboethoxy-cyclopentanone (2) to the corresponding cyclopentanol derivative (+)-(1R,2R)-(1) was accomplished employing baker's yeast in organic media. This chiral cyclopentanol derivative (1), analyzed by high resolution gas chromatography performed over beta-c...

journal_title：Chirality

authors： Fraga CA,Barreiro EJ,da Silva EF,dos Santos AR,KV Ramos MdaC,de Aquino Neto FR

更新日期：1997-01-01 00:00:00