Chiral separation and CD characterisation of enantiomeric cyclotriphosphazene derivatives.

abstract：:The racemic title host compound (1) formed homochiral inclusion crystals (conglomerate) of 1 with acetone, while heterochiral inclusion crystals (racemate) were obtained when complexed with ethyl acetate. Upon treatment of the homochiral inclusion crystals of 1 with gaseous acetyl chloride in the solid state, opticall...

journal_title：Chirality

authors： Tanaka K,Iwamoto T,Wada S,Frelek J,Caira MR

更新日期：2006-08-01 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：:Ifosfamide (IF), a potent chemotherapeutic agent for solid tumors, is known to cause high rates of nephrotoxicity in children with cancer, which is most likely due to the renal production of the metabolite chloroacetaldehyde. Using plasma samples obtained from pediatric oncology patients, we developed a simple nonderi...

journal_title：Chirality

authors： Aleksa K,Nava-Ocampo A,Koren G

更新日期：2009-07-01 00:00:00

abstract：:Racemic ketoconazole (KTZ) was the first orally active azole antifungal agent used in clinical practice and has become widely used in the treatment of mucosal fungal infections associated with AIDS immunosuppression and cancer chemotherapy. However, the use of KTZ has been limited because of adverse drug-drug interact...

journal_title：Chirality

authors： Dilmaghanian S,Gerber JG,Filler SG,Sanchez A,Gal J

更新日期：2004-02-01 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：:Cyclodextrins that are indiscriminately carboxymethylated at the 2-, 3-, and 6-positions are used as chiral NMR solvating agents for cationic substrates with phenyl, naphthyl, pyridyl, indoline, and indole rings. Enantiodifferentiation with the alpha-, beta-, and gamma-cyclodextrin derivatives is compared. The carboxy...

journal_title：Chirality

authors： Provencher KA,Weber MA,Randall LA,Cunningham PR,Dignam CF,Wenzel TJ

更新日期：2010-03-01 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：:Chiral discrimination in a racemic mixture of dipalmitoylphosphatidylcholine (DPPC) is induced by a new selector at the water-air interface: L-DPPC is segregated in the condensed phase of a Langmuir monolayer upon interactions with an enantiopure amphiphilic compound. ...

journal_title：Chirality

authors： Caminati G,Cicchi S,Lascialfari L,Brandi A

更新日期：2015-11-01 00:00:00

abstract：:Stereoselective aspects of pharmacokinetics and metabolism of a chiral nonsteroidal antiinflammatory drug, flobufen, 4-(2', 4'-difluorobiphenyl-4-yl)-2-methyl-4-oxobutanoic acid, were studied in male guinea pigs after p.o. administration of racemic flobufen (rac-flobufen) at a dose of 10 mg/kg. Blood samples were coll...

journal_title：Chirality

authors： Trejtnar F,Král R,Pávek P,Wsól V

更新日期：2003-10-01 00:00:00

abstract：:C(25) highly branched isoprenoid (HBI) alkenes are ubiquitous lipids found in geochemical samples around the globe. The origins of these widespread geochemicals are believed to be restricted to a limited number of diatoms, including Haslea ostrearia (and related species), Rhizosolenia setigera, and Pleurosigma interme...

journal_title：Chirality

authors： Belt ST,Allard WG,Johns L,König WA,Massé G,Robert JM,Rowland S

更新日期：2001-08-01 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：: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：: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：:The synthesis of the eight stereoisomers of muscarine has been efficiently accomplished by utilizing the two enantiomers of lactic esters as starting material. The synthetic strategy is based on a SnCl4-catalyzed addition of allyltrimethylsilane to O-protected lactic aldehydes followed by an iodocyclization process. A...

journal_title：Chirality

authors： De Amici M,Dallanoce C,De Micheli C,Grana E,Dondi G,Ladinsky H,Schiavi G,Zonta F

更新日期：1992-01-01 00:00:00

abstract：:After alkylation of a fraction of the total alpha-adrenoreceptors by phenoxybenzamine in rat vas deferens, the dissociation constants of (-)- and (+)-epinephrine in functional studies were 7 X 10(-7) M and 2 X 10(-5) M, respectively. In the adrenoreceptor-containing tissue fraction, when 3H-labeled WB4101 was used as ...

journal_title：Chirality

authors： Rice PJ,Miller DD,Sokoloski TD,Patil PN

更新日期：1989-01-01 00:00:00

abstract：:The direct Michael addition reaction of cyclohexanone/aliphatic aldehydes with nitroolefins, catalyzed by a novel chiral pyrrolidine-thiourea catalyst 1a, is described. The desired 1,4-adducts were obtained in moderate yields with enantioselectivities up to 99% ee and dr up to 99:1 of the syn product. ...

journal_title：Chirality

authors： Shen Z,Zhang Y,Jiao C,Li B,Ding J,Zhang Y

更新日期：2007-05-05 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：:Conditions for separation of enantiomers of a mandelic acid derivative, methyl 2-phenyl-2-(tetrahydropyranyloxy) acetate (the analyte) were studied. Because of the presence of two chiral carbons, the analyte consists of four stereoisomers stable at ambient temperature. Chiral HPLC of the analyte resulted in four peaks...

journal_title：Chirality

authors： Shen B,Xu X,Chen J,Zhang X,Xu B

更新日期：2006-09-01 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：:Many drugs contain a chiral centre, or such a centre is introduced during metabolism of the drug in man and in animals. If a single chiral centre is present, the drug will normally exist as a mixture of two enantiomers, of which one may have quite different pharmacologic and/or toxic effects than the other. Chiral dru...

journal_title：Chirality

authors： Coutts RT,Baker GB

更新日期：1989-01-01 00:00:00

abstract：:Several in vivo and in vitro studies on the stereoselective potency of isoflurane enantiomers suggest beneficial effects of the (+)-(S)-enantiomer. In order to detect possible differences in the pharmacokinetics of isoflurane enantiomers, a clinical study of 41 patients undergoing general anesthesia maintained with ra...

journal_title：Chirality

authors： Schmidt R,Wahl HG,Häberle H,Dieterich HJ,Schurig V

更新日期：1999-01-01 00:00:00

abstract：:The modern use of preparative chromatography in pharmaceutical development is illustrated by the case of a recent preclinical candidate from these laboratories. The synthesis of the candidate employed a coupling of two enantiopure intermediates, each of which could be resolved using preparative chiral chromatography. ...

journal_title：Chirality

authors： Leonard WR Jr,Henderson DW,Miller RA,Spencer GA,Sudah OS,Biba M,Welch CJ

更新日期：2007-09-01 00:00:00

abstract：:A Micelle-enhanced ultrafiltration (MEUF) separation process was investigated that can potentially be used for large-scale enantioseparations. Copper(II)-amino acid derivatives dissolved in nonionic surfactant micelles were used as chiral selectors for the separation of dilute racemic amino acids solutions. For the al...

journal_title：Chirality

authors： De Bruin TJ,Marcelis AT,Zuilhof H,Rodenburg LM,Niederländer HA,Koudijs A,Overdevest PE,Van der Padt A,Sudhölter EJ

更新日期：2000-08-01 00:00:00

abstract：:The chiral squaramide catalysts (8-15) were synthesized, and their catalytic efficiency in the enantioselective conjugate addition of pyrazolones to nitroalkenes was described. This protocol provides excellent chemical yields (up to 93%) of chiral 5-methyl-4-(2-nitro-1-arylethyl)pyrazol-3-ol derivatives with high enan...

journal_title：Chirality

authors： Aydin AE,Culha S

更新日期：2021-01-11 00:00:00

abstract：:Chiral fungicide prothioconazole has a wide range of antifungal spectrum; however, little research has been conducted to evaluate prothioconazole on an enantiomeric level. Five target pathogens and three common aquatic organisms were tested for the enantioselective bioactivity and toxicity of prothioconazole in this w...

journal_title：Chirality

authors： Zhai W,Zhang L,Cui J,Wei Y,Wang P,Liu D,Zhou Z

更新日期：2019-06-01 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

abstract：:A cyclic alpha-aminophosphonate was found to be a novel organocatalyst for Michael type addition reactions of carbonyl compounds to nitroolefins to afford the corresponding adducts in high enantio- and diastereoselectivities. ...

journal_title：Chirality

authors： Tao Q,Tang G,Lin K,Zhao YF

更新日期：2008-07-01 00:00:00

abstract：:1,1,1,3,3-pentafluoro-2-(fluoromethoxy)-3-methoxypropane, compound B, is a product obtained in the degradation of the anesthetic Sevoflurane. Enantiopure (+)-B was investigated using vibrational circular dichroism (VCD). Experimental absorption and VCD spectra of (+)-B in CDCl(3) solution in the 2,000-900 cm(-1) regio...

journal_title：Chirality

authors： Wang F,Polavarapu PL,Schurig V,Schmidt R

更新日期：2002-08-01 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：: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