Conformational spaces of Cinchona alkaloids.

abstract：:Chiral Eu3+ -based systems are frequently studied via circularly polarized luminescence spectroscopy. The emission lifetimes of each circular polarization, however, are virtually always ignored, because in a homogeneous sample of emitters, there should be no difference between the two. However, we show that in less ro...

journal_title：Chirality

authors： Hananel U,Schwartz G,Paiss G,Arrico L,Zinna F,Di Bari L,Cheshnovsky O,Markovich G

更新日期：2020-12-30 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

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：: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：:A series of 1,4-disubstituted piperazine derivatives with hypnotic activity were examined on three polysaccharide-based chiral stationary phases, namely, Chiracel OD, Chiracel OJ and Chiralpak AD. It was possible to resolve all the compounds on all the phases examined (1.13

journal_title：Chirality

authors： Chilmonczyk Z,Ksycinska H,Mazgajska M,Aboul-Enein HY

更新日期：1999-01-01 00:00:00

abstract：:Trigonostemons G and H, two novel dimeric dinorditerpenoids, were isolated from the stem barks of Trigonostemon chinensis. Their planar structures and relative configurations were established by extensive analysis of spectroscopic data. Trigonostemons G and H possess a homodimeric biaryl skeleton obtained from two rea...

journal_title：Chirality

authors： Zhu Q,Tang C,Mándi A,Kurtán T,Ye Y

更新日期：2020-03-01 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：:Ibuprofen was used to demonstrate that isolated rat hepatocytes offer a suitable in vitro model to investigate the metabolic chiral inversion of anti-inflammatory 2-arylpropionic acids (profens). The inversion of the pharmacologically inactive (-)-(R)-ibuprofen to the active (+)-(S)-ibuprofen was shown to obey apparen...

journal_title：Chirality

authors： Müller S,Mayer JM,Etter JC,Testa B

更新日期：1990-01-01 00:00:00

abstract：:The UV absorption and electronic circular dichroism (ECD) spectra of (R)- and (S)-nicotine and (S)-nornicotine in aqueous solution were measured to a significantly lower wavelength range than previously reported, allowing the identification of four previously unobserved electronic transitions. The ECD spectra of the t...

journal_title：Chirality

authors： Clayton PM,Vas CA,Bui TT,Drake AF,McAdam K

更新日期：2013-05-01 00:00:00

abstract：:Massarigenin A (1) and papyracillic acids A (2) and B (3) were isolated from the endophytic fungus Microsphaeropsis sp. Their structures were elucidated by multidimensional nuclear magnetic resonance spectroscopy; the structure of massarigenin A (1) was also confirmed by X-ray crystallography. The absolute configurati...

journal_title：Chirality

authors： Hussain H,Ahmed I,Schulz B,Draeger S,Flörke U,Pescitelli G,Krohn K

更新日期：2011-09-01 00:00:00

abstract：:The new linear polyesters, W1278-A, B, and C, were isolated from culture extracts of a freshwater Ascomycete fungus. Their structures were elucidated on the basis of spectroscopic analyses and chemical transformations, with the absolute configuration established by the circular dichroism (CD) method using (R)-(-)-6-hy...

journal_title：Chirality

authors： Schlingmann G,Roll DM

更新日期：2005-01-01 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：: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：: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 attempts of applying chiroptical spectroscopy to supramolecular chirality are reviewed with a focus on vibrational circular dichroism (VCD). Examples were taken from gels, solids, and monolayers formed by low-molecular mass weight chiral gelators. Particular attention was paid to a group of gelators with perfluoro...

journal_title：Chirality

authors： Sato H,Yajima T,Yamagishi A

更新日期：2015-10-01 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：:Studies on the interactions between L-O- phosphoserine, as one of the simplest fragments of membrane components, and the Cinchona alkaloid cinchonine, in the crystalline state were performed. Cinchoninium L-O-phosposerine salt dihydrate (PhSerCin) crystallizes in a monoclinic crystal system, space group P2(1), with un...

journal_title：Chirality

authors： Wesełucha-Birczyńska A,Oleksyn BJ,Watroba J

更新日期：2010-06-01 00:00:00

abstract：:The macrocyclic glycopeptide, ristocetin A, was covalently bonded to a silica gel support and evaluated as a liquid chromatographic (LC) chiral stationary phase (CSP). Over 230 racemates were resolved in either the reversed-phase mode, the normal-phase mode, or the polar-organic mode. The retention behavior and select...

journal_title：Chirality

authors： Ekborg-Ott KH,Liu Y,Armstrong DW

更新日期：1998-01-01 00:00:00

abstract：:Enantiopure 3-((R)- and 3-((S)-1-phenylethyl)-4-oxazoline-2-ones were evaluated as chiral building blocks for the divergent construction of heterocycles with stereogenic quaternary centers. The N-(R)- or N-(S)-1-phenylethyl group of these compounds proved to be an efficient chiral auxiliary for the asymmetric inductio...

journal_title：Chirality

authors： Santoyo BM,González-Romero C,Zárate-Zárate D,Hernández-Benitez RI,Pelayo V,Barrera E,Escalante CH,Fuentes-Benites A,Martínez-Morales G,López J,Vázquez MA,Delgado F,Jiménez-Vázquez HA,Tamariz J

更新日期：2019-09-01 00:00:00

abstract：:An environmental and sensitive sample pretreatment method was established and combined with high-performance liquid chromatography (HPLC) for the analysis of tetracycline hydrochloride (TC) in feed water and lake water. One element small molecule alcohol-salt aqueous two-phase system (ATPS) cannot effectively adjust t...

journal_title：Chirality

authors： Guo DG,Ni L,Wang L,Shao L

更新日期：2019-09-01 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：:Polymorphonuclear neutrophils (PMNs) are short-lived leukocytes that die by apoptosis. Although PMNs are crucial in the defense against infection, they have been implicated in the pathogenesis of tissue injury observed in inflammatory diseases. The induction or prevention of PMN apoptosis is currently discussed as a k...

journal_title：Chirality

authors： Zielińska-Przyjemska M,Główka FK,Klaczyńska J

更新日期：2008-02-01 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：:Racemic N-methyl-N-(1-methyl-4-pyrrolidino-2-butynyl)acetamide (BM-5), a putative postsynaptic agonist and presynaptic antagonist at muscarinic receptors, was resolved into the enantiomers by a new method suitable for large scale preparation. The method involves a chemoselective N-debenzylation as the key step. The en...

journal_title：Chirality

authors： Nilsson BM,De Boer P,Grol CJ,Hacksell U

更新日期：1992-01-01 00:00:00

abstract：:The hydrolysis and acyl migration of biosynthetic S-naproxen-beta-l-O-acyl glucuronide (I) and R-naproxen-beta-l-O-acyl glucuronide (II) was followed by HPLC. Nine first-order kinetic rate constants for the hydrolysis and acyl migration between the beta-l-O-acyl glucuronide, its alpha/beta-2, alpha/beta-3-, alpha/beta...

journal_title：Chirality

authors： Mortensen RW,Sidelmann UG,Tjørnelund J,Hansen SH

更新日期：2002-05-05 00:00:00

abstract：:This review tracks a decade of dynamic kinetic resolution developments with a biocatalytic inclination using enzymatic/microbial means for the resolution part followed by the racemization reactions either by means of enzymatic or chemocatalyst. These fast developments are due to the ability of the biocatalysts to sign...

journal_title：Chirality

authors： Kamaruddin AH,Uzir MH,Aboul-Enein HY,Halim HN

更新日期：2009-04-01 00:00:00

abstract：:Hornet silks adopt a variety of morphology such as fibers, sponge, films, and gels depending on the preparation methods. We have studied the conformation change of hornet silk proteins (Vespa mandarina) as regenerated films, using chiroptical spectrophotometer universal chiroptical spectrophotometer 1, which can measu...

journal_title：Chirality

authors： Kuroda R,Kameda T

更新日期：2018-05-01 00:00:00

abstract：:The assignment of the absolute configuration of novel anti-inflammatory pyrrole derivatives has been accomplished by a combined strategy based on independent physical methods. The key step of our stereochemical characterization approach is the production at mg-scale of enantiomerically pure forms by HPLC on Chiralpak ...

journal_title：Chirality

authors： Biava M,Cirilli R,Fares V,Ferretti R,Gallinella B,La Torre F,Poce G,Porretta GC,Supino S,Villani C

更新日期：2008-06-01 00:00:00

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 influence of endotoxin-induced inflammation on the enantioselective pharmacokinetics of propranolol, oxprenolol, and verapamil, which bind to alpha 1-acid glycoprotein, was studied in the rat. The racemic mixtures were given orally. In the control animals, for propranolol and oxprenolol, the plasma concentrations ...

journal_title：Chirality

authors： Laethem ME,Belpaire FM,Wijnant P,Rosseel MT,Bogaert MG

更新日期：1994-01-01 00:00:00