Absolute structural elucidation of natural products--a focus on quantum-mechanical calculations of solid-state CD spectra.

abstract：:Antimalarial drugs have shown potential in suppressing the role of glycosaminoglycans (GAGs) in the pathology of prion protein conformational disorders (e.g. "Mad Cow" disease) by competing for sites of electrostatic interaction. In this study, circular dichroism (CD) and UV/Visible (UV/Vis) absorption spectroscopy te...

journal_title：Chirality

authors： Stanley FE,Warner AM,McWilliams KM,Stalcup AM

更新日期：2011-01-01 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：:We introduce a method to detect the activity of ion channels and pores with circular dichroism (CD) spectroscopy. G-quartets obtained by potassium templated self-assembly of 5'-guanosine monophosphate (GMP) are used as CD probes, the bee-toxin melittin as representative pore and gramicidin A as representative ion chan...

journal_title：Chirality

authors： Hennig A,Matile S

更新日期：2008-09-01 00:00:00

abstract：:A calculation of the circular dichroism (CD) spectra of carbonmonoxy- and deoxy-myoglobin is carried out in relation to a time-resolved CD experiment. This calculation allows us to assign a dominant role to the proximal histidine in the definition of the electronic normal modes and to interpret the transient CD struct...

journal_title：Chirality

authors： Dartigalongue T,Hache F

更新日期：2006-05-05 00:00:00

abstract：:The optically active mixed-ligand fac(S)-tris(thiolato)rhodium(III) complexes, ΔL -fac(S)-[Rh(aet)2 (L-cys-N,S)](-) (aet = 2-aminoethanethiolate, L-cys = L-cysteinate) () and ΔLL -fac(S)-[Rh(aet)(L-cys-N,S)2 ](2-) were newly prepared by the equatorial preference of the carboxyl group in the coordinated L-cys ligand. T...

journal_title：Chirality

authors： Aizawa S,Tsubosaka S

更新日期：2016-01-01 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：:New chiral derivatizing reagents (CDAs) derived from trans-1,2-diaminocyclohexane, having an electron-deficient aromatic substituent (either an aromatic imide or 3,5-dinitrobenzamide) and rigid structure (either an amide or a urea linker), are reported. Significant shift differences of diastereotopic protons in the 1H...

journal_title：Chirality

authors： Kaik M,Gajewy J,Grajewski J,Gawronski J

更新日期：2008-03-01 00:00:00

abstract：:The chiral separation by counter-current chromatography has made great progress in the past three decades. It has become increasingly popular in the field of chiral separation, and many applications have been introduced during the last years. This review mainly focuses on the current topics, applications, and trends i...

journal_title：Chirality

authors： Duan WD,Huang XY,Di DL

更新日期：2020-10-01 00:00:00

abstract：:N-formylphenylalanine was subjected to optical resolution using a chiral agent such as phenylethylamine enantiomer, (R)-phenylglycine methyl ester, (S)-N-benzyl-2-aminobutanol, alone or in a mixture with each other or in a mixture with benzylamine. ...

journal_title：Chirality

authors： Pálovics E,Fogassy E,Schindler J,Nógrádi M

更新日期：2007-01-01 00:00:00

abstract：:Advances in the measurement, calculation, and application of vibrational circular dichroism (VCD) for the determination of absolute configuration are described. The purpose of the review is to provide an up-to-date perspective on the capability of VCD to solve problems of absolute stereochemistry for chiral molecules ...

journal_title：Chirality

authors： Freedman TB,Cao X,Dukor RK,Nafie LA

更新日期：2003-11-01 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：:The straightforward synthesis of a series of enantiomerically pure Lewis basic amides by simple condensation of commercially available enantiopure diamines with picolinic acid is reported. These compounds were shown to promote the enantioselective reduction of ketoimines with trichlorosilane. Working with the model su...

journal_title：Chirality

authors： Guizzetti S,Benaglia M,Cozzi F,Rossi S,Celentano G

更新日期：2009-01-01 00:00:00

abstract：:This work reports confirmation of the experimental assignment of the absolute-handedness chirality of single-walled carbon nanotubes (SWNTs). This was achieved by applying the scanning tunneling microscopy (STM) imaging technique to a supramolecular composite consisting of a metalized porphyrin derivative (nickel-5,15...

journal_title：Chirality

authors： Abd El-Mageed AIA,Ogawa T

更新日期：2020-03-01 00:00:00

abstract：:We have developed an improved circular dichroism (CD) and linear dichroism (LD) simultaneous measurement system for the vacuum ultraviolet (VUV) region by polarization modulation techniques using a four-period Onuki-type crossed undulator as a polarized light source. The system has been constructed at the VUV beamline...

journal_title：Chirality

authors： Tanaka M,Yagi-Watanabe K,Yamada T,Kaneko F,Nakagawa K

更新日期：2006-02-01 00:00:00

abstract：:Solid phase extraction (SPE)-chiral separation of the important drugs pheniramine, oxybutynin, cetirizine, and brinzolamide was achieved on the C18 cartridge and AmyCoat (150 x 46 mm) and Chiralpak AD (25 cm x 0.46 cm id) chiral columns in human plasma. Pheniramine, oxybutynin, cetirizine, and brinzolamide were resolv...

journal_title：Chirality

authors： Ali I,Al-Othman ZA,Al-Warthan A,Alam SD,Farooqi JA

更新日期：2014-03-01 00:00:00

abstract：:C2 -symmetric N,N-bis(phosphinomethyl)amines were prepared by the thermal reaction of aromatic aldehydes with ammonia and hypophosphorus acid as previously described. Both enantiomers of C2 -symmetric N,N-bis(phosphinomethyl)amine were obtained in a high enantiomeric purity through the diastereomeric salt formation wi...

journal_title：Chirality

authors： Kaboudin B,Faghihi MR,Kazemi F,Yokomatsu T

更新日期：2015-01-01 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：:The application of the Cartesian coordinate tensor transfer (CCT) technique for simulations of the IR absorption and vibrational circular dichroism (VCD) spectra of relatively large nucleic acid fragments is demonstrated on several case studies. The approach is based on direct ab initio calculations of atomic tensors,...

journal_title：Chirality

authors： Andrushchenko V,Bouř P

更新日期：2010-01-01 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：: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：:Both epimers of the naturally occurring nonproteinogenic amino acid L-cyclopentenylglycine, (2S,1'S)- and (2S, 1'R)-2-(cyclopent-2'-enyl)glycine, were obtained via a procedure involving condensation of 3-chlorocyclopentene with diethyl acetylaminomalonate, deethoxycarbonylation, chromatographic separation of the resul...

journal_title：Chirality

authors： Andersen L,Nielsen B,Jaroszewski JW

更新日期：2000-10-01 00:00:00

abstract：:Four Ala-Ala dipeptides with a perfluoroalkyl chain at the N-terminal were synthesized. They were able to self-assemble into helical nanofibers and/or twisted nanobelts in a mixture of DMSO/H2 O. The handedness of nanofibers and nanobelts was controlled by the chirality of the alanine at the N-terminal. The stacking h...

journal_title：Chirality

authors： Zhang L,Lin S,Tong Q,Li Y,Wang Y,Li Y,Li B,Yang Y

更新日期：2019-11-01 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：: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：: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 simple one-dimensional (13)C NMR method is presented to discriminate between stereoisomers of organic compounds with more than one chiral center. By means of this method it is possible to discriminate between all eight stereoisomers of α-tocopherol. To achieve this the chiral solvating agent (S)-(+)-1-(9-anthryl)-2,...

journal_title：Chirality

authors： Lankhorst PP,Netscher T,Duchateau AL

更新日期：2015-11-01 00:00:00

abstract：:Herein, we present the solution-state NMR studies on dextromethorphan (1) under both isotropic and anisotropic conditions. From the measurement of 22 residual dipolar couplings using a stretched polystyrene gel (PS), we show that accurate and detailed structural information is readily determined including the relative...

journal_title：Chirality

authors： Swarbrick JD,Ashton TD

更新日期：2010-01-01 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：: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：:Enzymatic hydrolysis with beta-glucuronidase/sulfatase was used for the enantioselective determination of N-hydroxymexiletine glucuronide in plasma for pharmacokinetic studies. N-Hydroxymexiletine glucuronide was determined as the quantity of mexiletine released by hydrolysis (difference between the enantiomeric conce...

journal_title：Chirality

authors： Lanchote VL,Santos VJ,Cesarino EJ,Dreossi SA,Mere Júnior Y,Santos SR

更新日期：1999-01-01 00:00:00