Enantiomeric separation and determination of absolute stereochemistry of asymmetric molecules in drug discovery: building chiral technology toolboxes.

abstract：:The first direct asymmetric synthetic preparation of trifluoro-1-(indol-3-yl)ethanols (TFIEs) is described by an enantioselective organocatalytic method from indoles and inexpensive trifluoroacetaldehyde methyl hemiacetal. The reaction is catalyzed by hydroquinine to produce TFIEs in an almost quantitative yield and w...

journal_title：Chirality

authors： Borkin DA,Landge SM,Török B

更新日期：2011-09-01 00:00:00

abstract：:The five-steps synthesis of a hemicryptophane cage combining a benzene-1,3,5-tricarboxamide unit and a cyclotriveratrylene (CTV) moiety is described. Chiral high-performance liquid chromatography (HPLC) was used to resolve the racemic mixture. The absolute configuration of the isolated enantiomers was assigned by comp...

journal_title：Chirality

authors： Long A,Jean M,Albalat M,Vanthuyne N,Giorgi M,Górecki M,Dutasta JP,Martinez A

更新日期：2019-11-01 00:00:00

abstract：:(+/-)-Pantoprazole ((+/-)-PAN), (+/-)-5-(difluoromethoxy)-2-[[3.4-dimethoxy-2-pyridinyl)methyl]sul finyl]- 1H-benzimidazole) is a chiral sulfoxide that is used clinically as a racemic mixture. The disposition kinetics of (+)-PAN and (-)-PAN given separately has been studied in rats. Serum levels of (+)- and (-)-PAN an...

journal_title：Chirality

authors： Masubuchi N,Yamazaki H,Tanaka M

更新日期：1998-01-01 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：: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：:One of the most powerful techniques that are currently available to measure thermodynamic parameters such as enthalpy (ΔH), Gibbs free energy (ΔG), entropy changes (ΔS), and binding affinity in chemical reactions is isothermal titration calorimetry (ITC). Recent advances in instrumentation have facilitated the develop...

journal_title：Chirality

authors： Werber L,Mastai Y

更新日期：2018-05-01 00:00:00

abstract：:We report the preparative separation of rac-zopiclone using malic acid as the resolving agent. Furthermore, two different methods for the analytical determination of zopiclone enantiomers by HPLC on chiral stationary phases are described. The benzodiazepine receptor binding of the isolated enantiomers was investigated...

journal_title：Chirality

authors： Blaschke G,Hempel G,Müller WE

更新日期：1993-01-01 00:00:00

abstract：:Despite the fact that several studies have reported the concentrations of various free amino acids in tobacco, their enantiomeric composition is unknown. Both the absolute and enantiomeric compositions of proline, alanine, asparagine, aspartic acid, valine, methionine, leucine,and phenylalanine were determined for thr...

journal_title：Chirality

authors： Kullman JP,Chen X,Armstrong DW

更新日期：1999-01-01 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：:Diastereomeric reduction of nonactivated, hindered β-keto and chiral β-iminoesters are described. The influence of a α-stereocontrolled center on the efficiency and stereoselectivity of the reduction was studied. Reaction conditions were optimized to synthesize β-hydroxy- and β-aminoesters in good yields. In the case ...

journal_title：Chirality

authors： Almahli H,Hendra F,Troufflard C,Cavé C,Joseph D,Delarue-Cochin S

更新日期：2011-03-01 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：:Optically active lumazines (biolumazine, dictyolumazine, monalumazine, and neolumazine) are prepared from the corresponding pterins by enzymatic reaction, using pterin deaminase excreted by Dictyostelium discoideum. The fluorescence properties, circular dichroism spectra, and chromatographic behavior of these lumazine...

journal_title：Chirality

authors： Klein R,Tatischeff I,Tham G,Mano N

更新日期：1994-01-01 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：: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：:Two diastereomeric cationic surfactants derived from L-proline, in which the second chiral center is a quaternary nitrogen, have been separated and fully characterized. The recognition properties of the aggregates formed by the two diastereomeric surfactants have been investigated by circular dichroism and (1)H NMR th...

journal_title：Chirality

authors： Borocci S,Ceccacci F,Galantini L,Mancini G,Monti D,Scipioni A,Venanzi M

更新日期：2003-05-15 00:00:00

abstract：:Although the organocatalytic direct asymmetric Michael reactions of carbonyl compounds to nitroalkenes have been investigated intensely, the Michael reaction of the thioether-based donors remains a rather undeveloped field. This work concerns the asymmetric Michael addition of aryl sulfanyl-propan-2-one to nitroalkene...

journal_title：Chirality

authors： Jiang X,Zhang B,Zhang Y,Lin L,Yan W,Wang R

更新日期：2010-07-01 00:00:00

abstract：:Searching the 3D structural fragments of organic molecules is challenging because of structural differences between X-ray and theoretically calculated geometries and the conformational flexibility of substituents. The codification program called Conformational Code for Organic Molecules (CCOM) can be used to unambiguo...

journal_title：Chirality

authors： Izumi H,Nafie LA,Dukor RK

更新日期：2016-05-01 00:00:00

abstract：:Bis(diamido)-bridged basket resorcin[4]arene (all-S)-1 and its (all-R)-1 enantiomer proved able to interact with 2'-deoxycytidine (2) and pyrimidine nucleoside analogs in dimethyl sulfoxide (DMSO) solution. In such a solvent, the resorcinarene hosts adopt a preferential 1,3-alternate-like conformation, with a larger c...

journal_title：Chirality

authors： D'Acquarica I,Calcaterra A,Sacco F,Balzano F,Aiello F,Tafi A,Pesci N,Uccello-Barretta G,Botta B

更新日期：2013-12-01 00:00:00

abstract：:Mirror symmetry breaking is ubiquitous in our visible universe taking place in elementary particles, atoms, and molecules. Molecular chirality is not biogenic in itself, although its detection is often considered a biosignature, a conjecture inferred from the fact that we do not know life devoid of homochirality. The ...

journal_title：Chirality

authors： Cintas P,Viedma C

更新日期：2012-11-01 00:00:00

abstract：:A new water soluble zinc-salophen complex with appended D-glucose moieties was synthesized and characterized. Its binding properties toward six aminoacids were investigated by UV-vis spectrophotometric titrations. Association constants showed to be unfavorably affected by increasing steric hindrance of the side chain....

journal_title：Chirality

authors： Dalla Cort A,De Bernardin P,Schiaffino L

更新日期：2009-01-01 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：:[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 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：:Treatment of benzoate, formate, or trifluoroacetate esters with silyldibromomethyllithiums provides alkyl silyl mixed acetals via the 1,3-rearrangement of a silyl group from carbon to oxygen. A high level of asymmetric induction onto the acetal carbon is observed when chiral alkyl esters are employed. The stereochemic...

journal_title：Chirality

authors： Shinokubo H,Kondo J,Inoue A,Oshima K

更新日期：2003-01-01 00:00:00

abstract：:Enantioseletive toxicities of chiral pesticides have become an environmental concern recently. In this study, we evaluated the enantiomeric separation of salithion on a suite of commercial chiral columns and assessed the toxicity of enantiomers toward butyrylcholinesterase and Daphnia magna. Satisfactory separations o...

journal_title：Chirality

authors： Zhou S,Lin K,Li L,Jin M,Ye J,Liu W

更新日期：2009-11-01 00:00:00

abstract：:A method for the determination of (R)- and (S)-atenolol in human plasma and urine is described. The enantiomers of atenolol are extracted into dichloromethane containing 3% heptafluorobutanol followed by acetylation with acetic anhydride at 60 degrees C for 2 h. The acetylated enantiomers were separated on a chiral al...

journal_title：Chirality

authors： Enquist M,Hermansson J

更新日期：1989-01-01 00:00:00

abstract：:Gold particles covered with 1,1'-binaphthyl-2,2'-dithiol (BINAS) were prepared. Using size exclusion chromatography, it was possible for the first time to separate the sample into fractions with different sizes and colors. Transmission electron microscopy shows that the particles are very small, in the order of 1 nm o...

journal_title：Chirality

authors： Gautier C,Taras R,Gladiali S,Bürgi T

更新日期：2008-03-01 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 electronic circular dichroism (ECD) spectra of two sesquiterpenoids (1 and 2) related to oplopanone, obtained from a methanolic extract of the plant Serphidium stenocephalum (Artemisia stenocephala), were measured and reproduced by means of time-dependent density functional theory (TDDFT) calculations, establishin...

journal_title：Chirality

authors： Shafiq N,Saleem M,Riaz N,Tousif MI,Jabbar A,Tareen RB,Pescitelli G

更新日期：2014-01-01 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