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Fluoxetine is used clinically as a racemic mixture of (+)‐(S) and (–)‐(R) enantiomers for the treatment of depression. CYP2D6 catalyzes the metabolism of both fluoxetine enantiomers. We aimed to evaluate whether exposure to gasoline results in CYP2D inhibition. Male Wistar rats exposed to filtered air (n = 36; control group) or to 600 ppm of gasoline (n = 36) in a nose‐only inhalation exposure chamber...
The separation of the four nadolol stereoisomers on Chiralpak® AD by chiral liquid chromatography was carried out at both analytical and preparative scales. A screening of possible mobile‐phase compositions was performed using different alcohol–hydrocarbon mixtures. The results obtained confirm the use of 20:80:0.3 ethanol‐hexane‐diethylamine reported by McCarthy (1994) but introduce other possibilities...
Coatline A (1) and α‐epi‐coatline A (4) co‐occur in the trunk extract of Andira coriacea. Inspection of their chiroptical properties led to intriguing results. After a careful examination of the experimental data used for the previously reported absolute configuration of these compounds, some uncertainties were identified. A combined theoretical approach including conformational analyses and calculation...
Chiral discrimination of homochiral and heterochiral H‐bonded complexes is a challenge for both experimentalists and computational chemists. It is demonstrated that a two‐pronged approach based on far‐infrared vibrational spectroscopy and the calculation of local mode frequencies facilitates the chiral discrimination of H‐bonded dimers. The local H‐bond stretching frequencies identify the strongest...
The 17‐phenyl PGF2α analogue bimatoprost (10a) is the most efficacious ocular hypotensive agent currently available for the treatment of glaucoma or ocular hypertension. A novel convergent synthesis of 13,14‐en‐15‐ol prostamideF2α analogues was developed employing Julia–Lythgoe olefination of the structurally advanced phenylsulfone (+)‐(5Z)‐15 with an enantiomerically pure aldehyde ω‐chain synthon...
The versatility of a previously developed method for the synthesis of chiral carbene‐based palladacycles is demonstrated through the synthesis of two new chiral pyridine‐functionalized N‐heterocyclic carbene palladacycles with different wingtip groups. The efficiency in their resolution with different counter anions and different chiral amino acid salt auxiliaries has been studied. The absolute stereochemistries...
Chiral pesticide enantiomers often show different bioactivity and toxicity; however, this property is usually ignored when evaluating their environmental and public health risks. Hexaconazole is a chiral fungicide used on a variety of crops for the control of many fungal diseases. This use provides opportunities for the pollution of food and soil. In this study, a sensitive and convenient chiral liquid...
Although the interactions between bilirubin and serum albumin are among the most studied serum albumin‐ligand interactions, the binding‐site location and the participation of bilirubin‐serum albumin complexes in pathological and physiological processes are under debate. In this article, we have benefited from the chiral structure of bilirubin and used CD spectroscopy to characterize the structure...
A simple, rapid, and sensitive method for the analysis of paroxetine, in tablets as well as the pure drug, by circular dichroism is described. The method was validated for repeatability, linearity, limit of detection, limit of quantification, and recovery according to the International Conference on Harmonization guidelines. Excellent results were obtained, within the globally accepted validation...
The chromatographic chiral resolution of 4‐aryl‐1,4‐dihydropyridines (1–32), 4‐aryl‐2‐thioxo‐1,2,3,4‐tetrahydropyrimidines (33–38), and 4‐aryl‐2‐oxo‐1,2,3,4‐tetrahydropyrimidines (39–41) was studied on a tetraproline‐immobilized chiral column synthesized in our lab. This tetraproline chiral stationary phase can resolve most of these compounds. The 4‐aryl‐2‐thioxo‐1,2,3,4‐tetrahydropyrimidines (33–38...
This article reports, for the first time, on the absolute configuration of (+)‐9‐benzyloxy‐α‐dihydrotetrabenazine (8), as determined from the perspective of X‐ray crystallography. Compound 8 was prepared by a six‐step reaction using 3‐benzyloxy‐4‐methoxybenzaldehyde (1) as a starting material. The X‐ray crystal diffraction structure of two compounds, racemic 9‐benzyloxy‐tetrabenazine (5) and the diastereomeric...
Diaziridines are very interesting representatives of organic compounds containing stereogenic nitrogen atoms. In particular, 1,2‐dialkyldiaziridines show extraordinarily high stereointegrity. The lone electron pairs of the nitrogen atoms are in trans configuration, avoiding a four‐electron repulsive interaction. Furthermore, the trans configuration of the substituents at the nitrogen atoms is energetically...
Three new polyketides (-)-1, (+)-1, and 2) were isolated from the EtOAc extract of the fungus Embellisia eureka, an endophyte of the Moroccan plant Cladanthus arabicus (Asteraceae). The structures of these new compounds were determined on the basis of one‐ and two‐dimensional NMR spectroscopy as well as by high‐resolution mass spectrometry. The absolute configurations of (-)-1, (+)-1, and 2 were determined...
New and original heterocyclic α‐enamido phosphine chiral solutes were prepared: four structurally similar racemates with the chirality center placed on the phosphorus atom, and four other related pairs of enantiomers with chirality borne by the carbon atoms of the phospholane ring. The structural variations were placed on an aliphatic heterocycle (six‐ or seven‐member rings) and on the carbamate function...
This article outlines theory and practice of the comparison of calculated and experimental electronic circular dichroism (ECD) curves to determine the absolute configuration of chiral molecules. The focus is on the evaluation of excited‐state calculations giving hints at the identification of the correct bandwidth and the application of the so‐called “UV shift” as a correction factor. A similarity...
A series of reports in the literature indicated symmetry breaking in assemblies of chiral molecules of opposite handedness. These unexpected observations could be accounted for as being generated by the “parity violation” of the nuclear weak force, combined with an autocatalytic amplification process. However, in many such cases, in particular of chiral fluids, this putative mechanism is far from...
The UV absorption and electronic circular dichroism (ECD) spectra of (R)‐ and (S)‐nicotine and (S)‐nornicotine in aqueous solution were measured to a significantly lower wavelength range than previously reported, allowing the identification of four previously unobserved electronic transitions. The ECD spectra of the two enantiomers of nicotine were equal in magnitude and opposite in sign, while the...
In the present work, we report a comprehensive vibrational circular dichroism (VCD) spectroscopic study of a chiral crown ether which features an axial chiral 3.3'‐diphenyl‐1,1'‐binaphthyl group as chiral moiety. By comparing the experimental and calculated VCD spectra, we show that the presumably very flexible crown ether preferably adopts only one ring conformation. Conformational flexibility is...
C75 is a synthetic compound described as having antitumoral properties. It produces hypophagia and weight loss in rodents, limiting its use in cancer therapy but identifying it as a potential anti‐obesity drug. C75 is a fatty acid synthase (FAS) inhibitor and, through its coenzyme A (CoA) derivative, it acts as a carnitine palmitoyltransferase (CPT) 1 inhibitor. Racemic mixtures of C75 have been used...
Enantiomeric compositions of three 2‐arylpropionic acid (2‐APA) drugs, ibuprofen, naproxen, and ketoprofen, were monitored in a membrane bioreactor (MBR) treating municipal effluent in a small rural town in Australia. Specific enantiomers were determined as amide diastereomers using the chiral derivatizing reagent, (R)‐1‐phenylethylamine (PEA), followed by gas chromatography–tandem mass spectrometry...
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