Rationalization of the multireceptorial character of chiral solvating agents based on quinine and its derivatives: overview of selected NMR investigations.

abstract：:An enantiocontrolled total synthesis of 19,20-dihydroakuammicine using a catalytic asymmetric Michael addition of dimethyl malonate to cyclohexenone as the key step is described. The above catalytic asymmetric Michael addition proceeds quite efficiently in the presence of a heterobimetalic asymmetric catalyst (ALB-KO-...

journal_title：Chirality

authors： Ohori K,Shimizu S,Ohshima T,Shibasaki M

更新日期：2000-06-01 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：: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：:Four racemic esters of (1R*,7aR*)-3,6,7,7a-tetrahydro-1-hydroxy-7a-methyl-1H-inden-5(2H)-one were prepared and subjected to hydrolysis with two types of hydrolases, including alcalase and three lipases. Alcalase and lipase showed opposite enantiopreference on these esters. Based on this result, we developed a gram-sca...

journal_title：Chirality

authors： Lo LC,Chou TC,Shie JJ

更新日期：2004-05-05 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：:Two new chiral thiosemicarbazide ligands and their Cu (II), Ni (II), Pd (II), and Zn (II) complexes were synthesized and characterized by nuclear magnetic resonance (NMR) (only for ligand), Fourier transform infrared (FT-IR), ultraviolet visible (UV-Vis), mass, and elemental analysis. The antioxidant activity of ligan...

journal_title：Chirality

authors： Başaran E,Sıcak Y,Sogukomerogullari HG,Karaküçük-Iyidoğan A,Oruç-Emre EE,Sönmez M,Öztürk M

更新日期：2019-06-01 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：: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：:Asymmetric molecular and supramolecular systems are characterized by: i. the circular dicroism in the angular distribution of valence photoelectrons emitted from randomly oriented chiral molecules by their interaction with circularly polarized VUV light; ii. the different stability and reactivity of diastereomeric agg...

journal_title：Chirality

authors： Giardini A,Paladini A,Catone D,Piccirillo S,Rondino F,Satta M,Filippi A,Speranza M,Turchini S,Zema N

更新日期：2006-08-01 00:00:00

abstract：:There is a great deal of current interest in the role and importance of chirality in the development of new drugs, but little attention is being paid to the stereochemistry of older drugs. Indeed, many older chiral drugs were introduced without adequate information on their stereochemical identity or composition. We h...

journal_title：Chirality

authors： Nusser E,Banerjee A,Gal J

更新日期：1991-01-01 00:00:00

abstract：:Human carboxylesterase 1 (hCES1) is an enzyme that plays an important role in hydrolysis of pharmaceuticals in the human liver. In this study, elucidation of the chiral recognition ability of hCES1 was attempted using indomethacin esters in which various chiral alcohols were introduced. Indomethacin was condensed with...

journal_title：Chirality

authors： Takahashi M,Takani D,Haba M,Hosokawa M

更新日期：2020-01-01 00:00:00

abstract：:Reaction of (S)- or (R)-3-aminoquinuclidine with 2-chloropyrimidine or 2-bromopyrimidine led to an unexpected formation of both cis- and trans-octahydropyrrolo [2,3]pyridine derivatives. A single-step synthesis of two of the four stereoisomers of these octahydropyrrolo[2,3]pyridine derivatives provides a convenient wa...

journal_title：Chirality

authors： Goljer I,Molinari A,He Y,Nogle L,Sun W,Campbell B,McConnell O

更新日期：2009-07-01 00:00:00

abstract：:We study the chiroptical properties of one-dimensional photonic crystals supporting superchiral surface waves by introducing a simple formalism based on the Fresnel reflection matrix. We show that the proposed framework provides useful insights on the behavior of all the relevant chiroptical quantities, allowing for a...

journal_title：Chirality

authors： Pellegrini G,Finazzi M,Celebrano M,Duò L,Biagioni P

更新日期：2018-07-01 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：:4-l-menthyloxycarbonyl 5-aryl prolinates were studied as organocatalysts of a novel three-component reaction of cyclohexanone, benzoic acid, and β-nitrostyrene. The presence of ortho-halogen atom in 5-aryl fragment of the catalyst is favored for driving the formation of chiral 7a-hydroxyoctahydro-2H-indol-2-one scaffo...

journal_title：Chirality

authors： Ivantcova PM,Kudryavtsev KV

更新日期：2020-06-01 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：:An enantioseparation of the antipsychotic drug butaclamol in human plasma by high-performance liquid chromatography (HPLC) with solid phase extraction is presented. The separation was achieved on the vancomycin macrocyclic antibiotic chiral stationary phase (CSP) Chirobiotic V with a polar ionic mobile phase (PIM) con...

journal_title：Chirality

authors： Aboul-Enein HY,Hefnawy MM

更新日期：2004-03-01 00:00:00

abstract：:Kynurenic acid (KYNA), an endogenous antagonist of N-methyl-D-aspartate and α(7) nicotinic acetylcholine receptors, is one of the L-tryptophan (Trp) metabolites. To compare the level of KYNA produced in the striatum of rats after independent administration of L-Trp and D-Trp, rats were intraperitoneally administered L...

journal_title：Chirality

authors： Ishii K,Iizuka H,Ogaya T,Song Z,Fukushima T

更新日期：2011-01-01 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：: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：:Chiral sulfoxides/N-oxides (R)-1 and (R,R)-2 are effective chiral promoters in the enantioselective allylation of α-keto ester N-benzoylhydrazone derivatives 3a-g to generate the corresponding N-benzoylhydrazine derivatives 4a-g, with enantiomeric excesses as high as 98%. Representative hydrazine derivatives 4a-b were...

journal_title：Chirality

authors： Reyes-Rangel G,Bandala Y,García-Flores F,Juaristi E

更新日期：2013-09-01 00:00:00

abstract：:Chiral pesticides are now receiving more and more attention in the food-making process. This experiment studied the enantioselective behavior of diclofop-methyl (DM) and its main metabolite, diclofop (DC), during the soy sauce brewing process. Two kinds of commonly used strains, Aspergillus oryzae and Saccharomyces ro...

journal_title：Chirality

authors： Lu Y,Zhang D,Liao Y,Diao J,Chen X

更新日期：2016-01-01 00:00:00

abstract：:The binding of the title benzodiazepine enantiomers and its modulation by warfarin and bilirubin were studied by chromatography on human serum albumin (HSA) immobilized on Sepharose 4B, and also by a combination of ultrafiltration and circular dichroism (UF-CD) methods. In the absence of warfarin and bilirubin the bin...

journal_title：Chirality

authors： Fitos I,Visy J,Magyar A,Kajtár J,Simonyi M

更新日期：1990-01-01 00:00:00

abstract：:Synthetic pyrethroid insecticides are chiral compounds with multiple asymmetric positions. In this study, isomers of four commonly used pyrethroids were separated at the enantiomeric level by enantioselective high-performance liquid chromatography (HPLC), and differences between enantiomers in aquatic toxicity were ch...

journal_title：Chirality

authors： Liu W,Gan JJ,Qin S

更新日期：2005-01-01 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：:The use of four cyclodextrins (three native and one beta-CD derivative) as NMR chiral solvating agents to resolve the enantiomers of (+/-)-cizolirtine, 1, and its chemical precursor (the carbinol, (+/-)-2), was investigated. The best enantiodiscrimination occurred when beta-cyclodextrin was used. ROESY experiments wer...

journal_title：Chirality

authors： Redondo J,Blázquez MA,Torrens A

更新日期：1999-01-01 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：:Glutathione (GSH) conjugation of the chiral compound 2-bromo-3-phenylpropionic acid (BPP) was studied in vitro and in the rat in vivo. GSH conjugation of BPP, catalyzed by a mixture of glutathione-S-transferases (GST's) from rat liver cytosol in vitro, was stereoselective: at a substrate concentration of 250 microM, (...

journal_title：Chirality

authors： Snel CA,Mahadevan S,Polhuijs M,Mulder GJ

更新日期：1992-01-01 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：: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