Base-catalyzed epimerization of the butenolide in annonaceous acetogenins.

abstract：:Vibrational circular dichroism (VCD) spectra of (+)-alpha-pinene solutions in carbon tetrachloride have been measured in the range of volume fractions 5-100% (v/v) in the mid-infrared region. The concentration dependence measured was statistically analyzed with the aim of obtaining a reliable correlation between the V...

journal_title：Chirality

authors： Urbanova M,Setnicka V V,Volka K

更新日期：2000-05-01 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：:The assignment of the absolute configuration of novel anti-inflammatory pyrrole derivatives has been accomplished by a combined strategy based on independent physical methods. The key step of our stereochemical characterization approach is the production at mg-scale of enantiomerically pure forms by HPLC on Chiralpak ...

journal_title：Chirality

authors： Biava M,Cirilli R,Fares V,Ferretti R,Gallinella B,La Torre F,Poce G,Porretta GC,Supino S,Villani C

更新日期：2008-06-01 00:00:00

abstract：:The resolution methods applying (-)-(4R,5R)-4,5-bis(diphenylhydroxymethyl)-2,2-dimethyldioxolane ("TADDOL"), (-)-(2R,3R)-α,α,α',α'-tetraphenyl-1,4-dioxaspiro[4.5]decan-2,3-dimethanol ("spiro-TADDOL"), as well as the acidic and neutral Ca(2+) salts of (-)-O,O'-dibenzoyl- and (-)-O,O'-di-p-toluoyl-(2R,3R)-tartaric acid ...

journal_title：Chirality

authors： Bagi P,Fekete A,Kállay M,Hessz D,Kubinyi M,Holczbauer T,Czugler M,Fogassy E,Keglevich G

更新日期：2014-03-01 00:00:00

abstract：:(R,R)-formoterol was synthesized in seven steps with 4-hydroxyl-3-nitro-acetophenone as the starting material. The key intermediate, the chiral secondary alcohol 4, was prepared via Rh-catalyzed asymmetric transfer hydrogenation with (S,S)-PEGBsDPEN as the ligand and sodium formate as the hydrogen donor under mild con...

journal_title：Chirality

authors： Huang L,Liu J,Shan W,Liu B,Shi A,Li X

更新日期：2010-02-01 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：:Doping nematic liquid crystals with nonracemic chiral compounds induces a twisted nematic (cholesteric) phase. The ability of solutes to twist the nematic phase may be related to the overall shape of the chiral dopant and consequently to its absolute configuration. The cholesteric induction is therefore a powerful too...

journal_title：Chirality

authors： Pieraccini S,Ferrarini A,Spada GP

更新日期：2008-05-15 00:00:00

abstract：:Plants and fungi are seemingly inexhaustible sources of interesting natural products with remarkable structural and biological diversity. One of the most important groups is the terpenes, ubiquitous natural products that are generated by 2 now well-established biosynthetic pathways: the older mevalonate and the more r...

journal_title：Chirality

authors： Reveglia P,Cimmino A,Masi M,Nocera P,Berova N,Ellestad G,Evidente A

更新日期：2018-10-01 00:00:00

abstract：:Ropivacaine hydrochloride monohydrate (ropivacaine) is a new local anaesthetic agent which is administered exclusively as the (-)-(S)-form. The aim of the study was to determine whether metabolic racemisation of (-)-(S)-ropivacaine occurs. This was tested in man, rat, dog, and sheep after different routes of administr...

journal_title：Chirality

authors： Arvidsson T,Bruce HF,Halldin MM

更新日期：1995-01-01 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：: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：: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：:We have previously shown that (RS)-2-amino-2-(5-tert-butyl-3-hydroxyisoxazol-4-yl)acetic acid (ATAA) is an antagonist at N-methyl-D-aspartic acid (NMDA) and (RS)-2-amino-3-(3-hydroxy-5-methylisoxazol-4-yl)propionic acid (AMPA) receptors. We have now resolved ATAA via diastereomeric salt formation using N-BOC protected...

journal_title：Chirality

authors： Johansen TN,Frydenvang K,Ebert B,Madsen U,Krogsgaard-Larsen P

更新日期：1997-01-01 00:00:00

abstract：:1alpha,25-Dihydroxyvitamin D(3) (1alpha,25(OH)2D3) has been shown to modulate not only proliferation and differentiation, but also apoptosis in malignant cells, indicating that it could be useful for the treatment of cancer and psoriasis. However, little information has been available on the binding conformation of th...

journal_title：Chirality

authors： Mikami K,Ohba S,Ohmura H,Kubodera N,Nakagawa K,Okano T

更新日期：2001-07-01 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 direct asymmetric aldol reactions of equivalent molar amounts of aldehydes and ketones were carried out at -20 degrees C over alkaline Al(2)O(3) with 20 mol % of Pro-Trp as catalyst and 20 mol % of N-methylmorpholine or 1,4-diazabicyclo[2.2.2]octane as additive. After simple and environmentally friendly work-up, m...

journal_title：Chirality

authors： Lei M,Xia S,Wang J,Ge Z,Cheng T,Li R

更新日期：2010-06-01 00:00:00

abstract：:Fourier transform infrared vibrational circular dichroism (FTIR-VCD) measurements have gone through major advances in the last decade. A major thrust in these advances was to find ways that can minimize the VCD spectral artifacts and obtain the VCD signals at enhanced signal quality. However, all these advances are no...

journal_title：Chirality

authors： Polavarapu PL,Shanmugam G

更新日期：2011-10-01 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：:Caffeic acid-derived polyethers are a class of natural products isolated from the root extracts of comfrey and bugloss, which are endowed with intriguing pharmacological properties as anticancer agents. The synthesis of new polyether derivatives is achieved through ring-opening polymerization of chiral 2,3-disubstitut...

journal_title：Chirality

authors： Tedesco D,Fabini E,Barbakadze V,Merlani M,Zanasi R,Chankvetadze B,Bertucci C

更新日期：2015-12-01 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：: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：:The pharmacokinetics of (-)-N-(trans-4-isopropylcyclohexanecarbonyl)-D-phenylalanine (nateglinide) and its enantiomer (L-enantiomer) was studied in Goto-Kakizaki (GK) rats after intravenous administration of nateglinide or L-enantiomer at a dose of 40 micromol/kg body weight. Nateglinide, its L-enantiomer and their me...

journal_title：Chirality

authors： Tamura M,Shiba S,Kudo N,Kawashima Y

更新日期：2010-01-01 00:00:00

abstract：:Three N,N-dimethylcarbamyl derivatives of oxazepam (1-(N,N-dimethylcarbamyl)oxazepam, 3-O-(N,N-dimethylcarbamyl)oxazepam, and 1,3-O-bis(N,N-dimethylcarbamyl) oxazepam) and a 3-O-acyl-1-(N,N-dimethylcarbamyl)-oxazepam were synthesized from either oxazepam or demoxepam. Enantiomeric pairs of these derivatives and of cam...

journal_title：Chirality

authors： Yang SK,Lu XL

更新日期：1991-01-01 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 application of Chiral Technology, or the (extensive) use of techniques or tools for the determination of absolute stereochemistry and the enantiomeric or chiral separation of racemic small molecule potential lead compounds, has been critical to successfully discovering and developing chiral drugs in the pharmaceut...

journal_title：Chirality

authors： McConnell O,Bach A 2nd,Balibar C,Byrne N,Cai Y,Carter G,Chlenov M,Di L,Fan K,Goljer I,He Y,Herold D,Kagan M,Kerns E,Koehn F,Kraml C,Marathias V,Marquez B,McDonald L,Nogle L,Petucci C,Schlingmann G,Tawa G,Tis

更新日期：2007-09-01 00:00:00

abstract：:The biodegradation of the chiral phenoxyalkanoic herbicides 2-(2,4-dichlorophenoxy)propionic aid (2,4-DP) and 2-(4-chloro-2-methylphenoxy)propionic acid (MCPP) was investigated using enantioselective HPLC and chiroptical detection. Racemic mixtures of 2,4-DP and MCPP were applied to three species of turf grass, four s...

journal_title：Chirality

authors： Schneiderheinze JM,Armstrong DW,Berthod A

更新日期：1999-01-01 00:00:00

abstract：:Searching the 3D structural fragments of organic molecules is challenging because of structural differences between X-ray and theoretically calculated geometries and the conformational flexibility of substituents. The codification program called Conformational Code for Organic Molecules (CCOM) can be used to unambiguo...

journal_title：Chirality

authors： Izumi H,Nafie LA,Dukor RK

更新日期：2016-05-01 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：:Previously, a diazaphospholidine has been synthesized and evaluated as a chiral derivatizing reagent for the determination of the optical purity of chiral alcohols via 31P NMR spectroscopy (Alexakis et al., J. Org. Chem. 57:1224-1237, 1992). Our laboratory is interested in the advantageous and practical applications o...

journal_title：Chirality

authors： House KL,O'Connor MJ,Silks LA 3rd,Dunlap RB,Odom JD

更新日期：1994-01-01 00:00:00

abstract：:We report the preparative separation of rac-zopiclone using malic acid as the resolving agent. Furthermore, two different methods for the analytical determination of zopiclone enantiomers by HPLC on chiral stationary phases are described. The benzodiazepine receptor binding of the isolated enantiomers was investigated...

journal_title：Chirality

authors： Blaschke G,Hempel G,Müller WE

更新日期：1993-01-01 00:00:00