Additional criterion for the determination of the handedness of 2(1) helices in crystals of bile acids: Crystal structure of a tert-butylphenyl derivative of cholic acid.

abstract：:Stereoselective high-performance liquid chromatographic separations of eight sterically constrained cyclic β-amino acid enantiomer pairs were carried out using the newly developed Cinchona alkaloid-based zwitterionic chiral stationary phases Chiralpak ZWIX(+) and ZWIX(-). The effects of the mobile phase composition, t...

journal_title：Chirality

authors： Ilisz I,Gecse Z,Lajkó G,Forró E,Fülöp F,Lindner W,Péter A

更新日期：2015-09-01 00:00:00

abstract：:Herein we report CD spectroscopic studies on complexes of (R,R)-dimethyl-, (R,R)-diisobutyl-, and (S,S)-di-sec-butyl-phenazino-18-crown-6 ligands (Scheme 1) with selected alkali (Na+, K+), alkaline earth (Mg2+, Ca2+), and transition-metal (Ag+, Zn2+, Ni2+, Cd2+, Pb2+) cations. The complexation was monitored in the 300...

journal_title：Chirality

authors： Szarvas S,Szalay L,Vass E,Hollósi M,Samu E,Huszthy P

更新日期：2005-06-01 00:00:00

abstract：:Benalaxyl (BX), methyl-N-phenylacetyl-N-2,6-xylyl alaninate, is a potent acylanilide fungicide and consist of a pair of enantiomers. The stereoselective metabolism of BX was investigated in rat and rabbit microsomes in vitro. The degradation kinetics and the enantiomer fraction (EF) were determined using normal high-p...

journal_title：Chirality

authors： Zhang P,Zhu W,Dang Z,Shen Z,Xu X,Huang L,Zhou Z

更新日期：2011-02-01 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 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 direct separation of the enantiomers of 1-(α-aminoarylmethyl)-2-naphthol, 1-(α-aminoalkyl)-2-naphthol, 2-(α-aminoarylmethyl)-1-naphthol analogs, and 2-(1-amino-2-methylpropyl)-1-naphthol) was performed on a newly developed chiral stationary phase containing isopropyl carbamate-cyclofructan6 as chiral selector, wit...

journal_title：Chirality

authors： Aranyi A,Ilisz I,Pataj Z,Szatmári I,Fülöp F,Armstrong DW,Péter A

更新日期：2011-08-01 00:00:00

abstract：:The separation methods of the enantiomers of two β-blockers and tryptophan were studied using capillary electrochromatography with heparin covalently as well as non-covalently, bonded onto the capillary inner wall as stationary phase and electrokinetic chromatography with heparin as pseudostationary phase. In the case...

journal_title：Chirality

authors： Liu Y,Sombra LL,Stege PW

更新日期：2018-06-25 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：:Three aldohexoses, glucose, galactose, and mannose, and three aldopentoses, arabinose, xylose, and ribose, were derivatized with L-tryptophanamide (L-TrpNH2 ) under alkaline conditions. Using a basic mobile phase (pH 9.2), the three aldohexoses or the three aldopentoses were simultaneously enantioseparated, respective...

journal_title：Chirality

authors： Shou M,Terashima H,Aizawa S,Taga A,Yamamoto A,Kodama S

更新日期：2015-07-01 00:00:00

abstract：:Vitamin E is an essential nutrient of still increasing economic importance. Vitamin E derivatives include many nonracemic chiral compounds whose chirooptical characterization is scarcely described in the literature. We report the CD spectra of delta-tocopherol and its unsaturated analog delta-tocotrienol. TDDFT calcul...

journal_title：Chirality

authors： Mazzini F,Pescitelli G,Di Bari L,Netscher T,Salvadori P

更新日期：2009-01-01 00:00:00

abstract：:Weinreb amide 3 was synthesized using isobutyl chloroformate, carbonyldiimidazole, or ethylcarbodiimide as the coupling agent in the reaction of Boc-phenylalanine with O,N-dimethylhydroxylamine hydrochloride. An optically active oil was isolated along with an optically inactive solid irrespective of the type of coupli...

journal_title：Chirality

authors： Zheng X,Donkor IO,Miller DD,Ross CR 2nd

更新日期：2000-01-01 00:00:00

abstract：:Compound A, a novel disubstituted pyrrolidine acid, is a member of a new class of agents that are potentially useful for the treatment of diabetes and dyslipidemia. The absolute configuration of this compound was determined by using vibrational circular dichroism (VCD). The results are in agreement with the assignment...

journal_title：Chirality

authors： Freedman TB,Cao X,Phillips LM,Cheng PT,Dalterio R,Shu YZ,Zhang H,Zhao N,Shukla RB,Tymiak A,Gozo SK,Nafie LA,Gougoutas JZ

更新日期：2006-09-01 00:00:00

abstract：:8-Prenylnaringenin (8PN) is a naturally occurring bioactive chiral prenylflavonoid found most commonly in the female flowers of hops (Humulus lupulus L.). A stereospecific method of analysis for 8PN in biological fluids is necessary to study the pharmacokinetic disposition of each enantiomer. A novel and simple liquid...

journal_title：Chirality

authors： Martinez SE,Lakowski TM,Davies NM

更新日期：2014-08-01 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：:An improved synthesis of the enantiomers of the new benzofurane-type antiarrhythmic compound 1 is described, which makes use of the enantiomerically pure mbe-lactol. Thus, acylation of the benzofurane 4 with acetic anhydride and subsequent bromination gave the bromoacetyl-derivative 6, which, after reduction with LiAl...

journal_title：Chirality

authors： Ecker G,Fleischhacker W,Helml T,Noe CR,Scasny S,Lemmens-Gruber R,Studenik C,Marei H,Heistracher P

更新日期：1994-01-01 00:00:00

abstract：:Perfluorooctane sulfonate (PFOS) is one of the most frequently detected perfluoroalkyl substances in environmental and human samples. Previous studies have shown that nonracemic PFOS in biological samples can be used as a marker of PFOS exposure sources. In recent years, supercritical fluid chromatography (SFC) has em...

journal_title：Chirality

authors： Zhao L,Chen F,Guo F,Liu W,Liu K

更新日期：2019-10-01 00:00:00

abstract：:The novel chiral spirobipyridopyrans 1 and 2 were synthesized by the acid catalyzed aldol type condensation of 5-deoxypyridoxal with the appropriate ketone and subsequent reaction of the resulting pyrylium salt with base. The indolinospiropyridopyrans 3-5, which contain the modified B(6) unit, were prepared by aldol r...

journal_title：Chirality

authors： Loncar-Tomaskovic L,Pustet N,Mrvos-Sermek D,Nagl A,Mintas M,Mannschreck A

更新日期：2001-02-01 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：:Steady-state pharmacokinetics of indobufen (INDB) enantiomers administered as racemic INDB (rac-INDB) tablets and bleeding time were studied in patients. Two-hundred mg INDB tablets (Ibustrin) were administered twice daily for 7 days to obliterative atherosclerosis patients. Enantiospecific reversed phase (RP) HPLC wi...

journal_title：Chirality

authors： Glówka FK,Strzelecka D,Zapalski S

更新日期：2001-06-01 00:00:00

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 present study describes a generic strategy using capillary electrophoretic (CE) method for chiral enantioseparation of anti-Alzheimer drugs, namely, donepezil (DON), rivastigmine (RIV), and antifungal drugs, namely, ketoconazole (KET), Itraconazole (ITR), fluconazole (FLU), and sertaconazole (SRT) in which these d...

journal_title：Chirality

authors： Abdel-Megied AM,Hanafi RS,Aboul-Enein HY

更新日期：2018-02-01 00:00:00

abstract：:Results achieved by the authors in the synthesis of chiral P,N-phosphite ligands are summarized. Three groups of new chiral P,N-phosphites are discussed, namely, ligands derived from 1,1'-bi-2-naphthol, ligands possessing an acyclic phosphorus center, and P*-chiral ligands derived from (S)-2-anilinomethylpyrrolidine. ...

journal_title：Chirality

authors： Gavrilov KN,Bondarev OG,Korostylev AV,Polosukhin AI,Tsarev VN,Kadilnikov NE,Lyubimov SE,Shiryaev AA,Zheglov SV,Gais HJ,Davankov VA

更新日期：2003-01-01 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：:This work presents results of methyl 7-oxoabiet-13(14)-en-18-oate (3) self-oxidation with air-oxygen in the presence of various bases such as triethylamine or sodium t-butoxide. While under aerobic conditions, the use of sodium t-butoxide as a base results in the formation of four isomeric alcohols, an addition of tri...

journal_title：Chirality

authors： Masnyk M,Kuśmirek D,Trzybiński D,Frelek J

更新日期：2020-04-01 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：: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：:A new enantiomerically pure P-chiral phosphine, (S)-cyclohexylmethyl- (1-naphthyl)phosphine (1) was prepared by phosphine-borane methodology and used in a mechanistic study of the Mitsunobu reaction. Enantiomerically enriched (S)-cyclo- hexylmethyl(1-naphtyl)phosphine oxide (8) is obtained if the reaction proceeds thr...

journal_title：Chirality

authors： Watanabe T,Gridnev ID,Imamoto T

更新日期：2000-06-01 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 this review, the recently reported approaches for the preparation of cyclodextrin-functionalized capillary monolithic columns are highlighted, with few applications in chiral separations using capillary liquid chromatography (CLC) and capillary electrochromatography (CEC). Chirality 28:97-109, 2016. © 2015 Wiley Pe...

journal_title：Chirality

authors： Adly FG,Antwi NY,Ghanem A

更新日期：2016-02-01 00:00:00

abstract：:The stereochemistry of tolperisone, a chiral aryl-alkyl basic ketone was investigated by means of circular dichroism (CD) and ultraviolet (UV) spectroscopy. The unusually high optical activity of tolperisone hydrochloride in the n-->pi* region is interpreted by the presence of a chiral conformer in solution. For stere...

journal_title：Chirality

authors： Zsila F,Hollósi M,Gergely A

更新日期：2000-11-01 00:00:00