Structure and unexpected chiroptical properties of chiral 4-pyrrolidinyl substituted 2(5H)-furanones.

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：:Chirality is often glossed over in theoretical or experimental discussions concerning the origin of life, but the ubiquity of homochiral building blocks in known biological systems demands explanation. Information theory can provide a quantitative framework for understanding the role of chirality in biology. Here I sh...

journal_title：Chirality

authors： Carroll JD

更新日期：2009-03-01 00:00:00

abstract：:Massarigenin A (1) and papyracillic acids A (2) and B (3) were isolated from the endophytic fungus Microsphaeropsis sp. Their structures were elucidated by multidimensional nuclear magnetic resonance spectroscopy; the structure of massarigenin A (1) was also confirmed by X-ray crystallography. The absolute configurati...

journal_title：Chirality

authors： Hussain H,Ahmed I,Schulz B,Draeger S,Flörke U,Pescitelli G,Krohn K

更新日期：2011-09-01 00:00:00

abstract：:We demonstrate by using vibrational circular dichroism (VCD) spectroscopy that it is possible to investigate the chirality of a supramolecular polymeric system in relatively dilute solutions. Chiral C(3)-symmetrical discotic molecules, based on a trialkylbenzene-1,3,5-carboxamide, form supramolecular columnar stacks w...

journal_title：Chirality

authors： Smulders MM,Buffeteau T,Cavagnat D,Wolffs M,Schenning AP,Meijer EW

更新日期：2008-09-01 00:00:00

abstract：:Trigonostemons G and H, two novel dimeric dinorditerpenoids, were isolated from the stem barks of Trigonostemon chinensis. Their planar structures and relative configurations were established by extensive analysis of spectroscopic data. Trigonostemons G and H possess a homodimeric biaryl skeleton obtained from two rea...

journal_title：Chirality

authors： Zhu Q,Tang C,Mándi A,Kurtán T,Ye Y

更新日期：2020-03-01 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：:Midodrine hydrochloride is a peripheral alpha(1)-adrenoreceptor agonist that induces venous and arterial vasoconstriction. Midodrine, after oral or intravenous administration, undergoes enzymatic hydrolysis and releases deglymidodrine, a pharmacologically active metabolite. Midodrine and deglymidodrine have a chiral c...

journal_title：Chirality

authors： Quaglia MG,Farina A,Palmery M,Desideri N,Donati E,Bossù E,Strano S

更新日期：2004-07-01 00:00:00

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：:This review brings together the past and current methods for synthesizing the classical cucurbit[n]uril (Q[n]), structural variants, and derivatives. Here we refer to the first family of Q[n] as " classical," where the cavity is spheroidal and carry no substituents at any of the equatorial methine carbons or the methy...

journal_title：Chirality

authors： Mandadapu V,Day AI,Ghanem A

更新日期：2014-11-01 00:00:00

abstract：:A rapid and effective RP-UHPLC-DAD method for enantioseparation of three flavanones, i.e., flavanone, naringenin, and hesperetin, was developed and validated. Chromatographic separation of the analytes was performed using a Chiralpak AD-3R analytical column under reverse phase conditions with methanol as the mobile ph...

journal_title：Chirality

authors： Baranowska I,Hejniak J,Magiera S

更新日期：2016-02-01 00:00:00

abstract：:We report here a sensitive method for the determination of the absolute configurations of primary amines using exciton-coupled circular dichroism (ECCD). The method works on a microgram scale by derivatization of chiral amines with quinoline chromophores. Complexation of the chiral ligands with metal ion fixes the geo...

journal_title：Chirality

authors： Zhang J,Holmes AE,Sharma A,Brooks NR,Rarig RS,Zubieta J,Canary JW

更新日期：2003-02-01 00:00:00

abstract：:Six enantiomeric pairs of TADDOL-s gathered in two series with either methyl (series A) or phenyl (series B) substituent in 2-position of the dioxolane ring were studied by vibrational circular dichroism (VCD). Experimental IR and VCD spectra associated with density functional theory (DFT) calculations showed that the...

journal_title：Chirality

authors： Uncuta C,Bartha E,Gherase D,Teodorescu F,Draghici C,Cavagnat D,Daugey N,Liotard D,Buffeteau T

更新日期：2010-01-01 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：:Three β-keto sulfoxides (1-3) were synthesized in enantiopure form and investigated by means of circular dichroism (CD) spectroscopy, both in electronic and vibrational range (ECD, VCD), in combination with quantum chemical calculations. For compound 2, the X-ray structure was available; thus, the ECD in the solid sta...

journal_title：Chirality

authors： Górecki M,Capozzi MAM,Albano G,Cardellicchio C,Di Bari L,Pescitelli G

更新日期：2018-01-01 00:00:00

abstract：:Allyl nitrite, O=NOCH(2)CH=CH(2), can exist in conformations which include syn (S) and anti (A) configurations of O=N-O-C, anti or gauche (G) configurations of N-O-C-C, and syn or skew (Sk) configurations of O-C-C=C. Four of them have been observed and characterized by their microwave spectra and quantum chemical calc...

journal_title：Chirality

authors： Lee SG,Breeze L,Bohn RK,True NS

更新日期：2002-02-01 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：:The enantioselective hydrogenation of C==N-C group containing compounds over modified metal catalysts is as yet an uninvestigated research area. This work contains results obtained on the hydrogenation of 1-pyrroline-2-carboxylate esters and sodium salt over cinchona alkaloid-modified alumina-supported Pd catalyst. Th...

journal_title：Chirality

authors： Szöllösi G,Kun I,Bartók M

更新日期：2001-01-01 00:00:00

abstract：:In the past years, enantioanalysis became very important for clinical analysis; biomarkers/substances of biomedical importance with chiral structure should be analyzed and their presence correlated with the specific disorder. Therefore, we developed a method for the assay of l- and d-glucose, based on molecular recogn...

journal_title：Chirality

authors： Stefan-van Staden RI,Mitrofan G

更新日期：2018-05-01 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

abstract：:Both novel enantiopure trans-1-aminobenz[f]indan-2-ols (4) were obtained from the racemate by the diastereomeric salt formation with (+)- and (-)-dibenzoyltartaric acids (8), respectively, and the absolute configuration of the enantiomer 4 in the less-soluble diastereomeric salt of racemic 4 with (+)-8 was determined ...

journal_title：Chirality

authors： Kobayashi Y,Kinbara K,Sato M,Saigo K

更新日期：2005-02-01 00:00:00

abstract：:The known complex trans-RuCl2(NBD)Py2 (1, NBD is norbornadiene, Py is pyridine) reacts with either (R)-BINAP ((R)-2, 2'-bis(diphenylphosphino)-1,1'-binaphthyl), (S;S)-Chiraphos ((2S;3S-(-)-2,3-bis(diphenylphosphino)butane), (S;S)-Skewphos ((2S;4S)-(-)-2,4-bis(diphenylphosphino)pentane), (R)-(S)-Josiphos ((R)-(-)-1-[(S...

journal_title：Chirality

authors： Akotsi OM,Metera K,Reid RD,McDonald R,Bergens SH

更新日期：2000-06-01 00:00:00

abstract：:Integrating spheres are widely used with UV-Vis and occasionally with infrared spectrophotometers to measure different types of samples, either in transmission mode (scattered transmission accessories) or in total/diffuse reflectance mode. We built a prototype sphere of the demountable type, which fits easily the samp...

journal_title：Chirality

authors： Castiglioni E,Albertini P

更新日期：2000-05-01 00:00:00

abstract：:Recent discovery of asymmetric desymmetrization of meso-heterocycles using (R,R)-(salen)manganese complex 2 as a catalyst allowed easy access to optically active 2,3,4-trisubstituted pyrrolidines. Taking advantage of this new reaction, we could achieve the short-step synthesis of (-)-swainsonine 1. ...

journal_title：Chirality

authors： Punniyamurthy T,Irie R,Katsuki T

更新日期：2000-06-01 00:00:00

abstract：:The hydrolysis and acyl migration of biosynthetic S-naproxen-beta-l-O-acyl glucuronide (I) and R-naproxen-beta-l-O-acyl glucuronide (II) was followed by HPLC. Nine first-order kinetic rate constants for the hydrolysis and acyl migration between the beta-l-O-acyl glucuronide, its alpha/beta-2, alpha/beta-3-, alpha/beta...

journal_title：Chirality

authors： Mortensen RW,Sidelmann UG,Tjørnelund J,Hansen SH

更新日期：2002-05-05 00:00:00

abstract：:We present a new concept of synthesis for preparation of molecularly imprinted polymers using a functionalized initiator to replace the traditional functional monomer. Using propranolol as a model template, a carboxyl-functionalized radical initiator was demonstrated to lead to high-selectivity polymer particles prepa...

journal_title：Chirality

authors： Liu W,Holdsworth C,Ye L

更新日期：2020-03-01 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：:Ninety isolates of microorganisms belonging to different taxonomical groups (30 bacteria, 20 yeast, and 40 fungi) were previously isolated from various samples. These isolates were screened as reducing agents for acetophenone 1a to phenylethanol 2a. It was found that the isolate EBK-10 was the most effective biocataly...

journal_title：Chirality

authors： Zilbeyaz K,Kurbanoglu EB

更新日期：2010-10-01 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：: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：: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