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Environmental enantioselectivity information is important to fate assessment of chiral contaminants. Warfarin, a rodenticide and prescription medicine, is a chiral chemical but used in racemic form. Little is known about its enantioselective behavior in the environment. In this study, enantioselective degradation of warfarin in a turfgrass and a groundcover soils was examined in aerobic and ambient...
Mandelic acid (MA) is generally used as a biological indicator of occupational exposure to styrene, which is classified as a class of hazardous environmental pollutants. It was found to undergo one‐directional chiral inversion (S‐MA to R‐MA) in Wistar and Sprague‐Dawley rats in vivo. This study was aimed to explore the metabolic mechanism of chiral inversion of S‐MA in vitro. S‐MA was converted to...
The deracemization of bilirubin in micellar aggregates of structurally correlated chiral surfactants was studied by circular dichroism experiments and exploited as the marker of the expression of chirality of the aggregates. The obtained results suggest that the hydrophobic interactions control the transfer of chirality from the monomers to the aggregates, and that different regions of the same aggregate...
The best reaction condition of Candida antartica lipase B as biocatalyst, 3‐(2‐pyridyl)pyrazole as leaving azole, and water‐saturated methyl t‐butyl ether as reaction medium at 45°C were first selected for performing the hydrolytic resolution of (R,S)‐2‐(4‐chlorophenoxyl) azolides (1, 2, 3, 4). In comparison with the kinetic resolution of (R,S)‐2‐phenylpropionyl 3‐(2‐pyridyl)pyrazolide or (R,S)‐α‐methoxyphenylacetyl...
Stabilization energies of the electron donor–acceptor sulfinimine···BF3 complexes calculated at either the B3LYP/aug‐cc‐pVTZ or the MP2/aug‐cc‐pVTZ level do not allow to judge, whether the N‐ or O‐atom in sulfinimine is stronger electron‐donor to BF3. The problem seems to be solvable because chirality transfer phenomenon between chiral sulfinimine and achiral BF3 is expected to be vibrational circular...
In recent years, the field of chiral ionic liquids (CILs) has undergone exponential growth. As the technology has advanced, new ways of synthesizing stable and structurally diverse ionic liquids have been established. This has led to heretofore unknown applications of CILs as well as in improving efficiency of previously identified applications. In this review article we have compiled a comprehensive...
The aim of this study was to assess the stereoselectivity of two tebuconazole [(RS)‐1‐p‐chlorophenyl‐4,4‐dimethyl‐3‐(1H‐1,2,4‐triazol‐1‐ylmethyl)pentan‐3‐ol] enantiomers in in vitro system (rat liver microsomes). The analytes were extracted with acetic ether and concentrations were determined by high performance liquid chromatography (HPLC) with a cellulose tris(3,5‐dimethylphenylcarbamate)‐based...
In this work, the enantioseparation of 15 structurally similar chiral solutes is studied, and analysis of the retention factors is performed using a genetic algorithm and multiple linear regression analysis technique. The present quantitative structure–enantioselective retention relationship model generated for retention factors' data has confirmed the importance of a number of descriptors altering...
A simple approach to the automated screening of four different columns on a single gas chromatography (GC) instrument is used for rapid chiral GC method development. Configuration of a conventional GC instrument with a second autosampler and several inexpensive Y‐splitters enables simultaneous evaluation of two different columns, allowing a total of four different columns to be evaluated in two automated...
Four regioselective‐carbamoylated cellulose derivatives having two different substituents at 2‐, 3‐, and 6‐position were prepared and evaluated as chiral stationary phases (CSPs) for high‐performance liquid chromatography. Investigations showed that the nature andarrangement of the substituents significantly influenced the chiral recognition abilities of the heterosubstituted cellulose derivatives...
Novel chiral calix[4]arene derivatives bearing amino alcohol moieties at the lower rim have been synthesized from the reaction of p‐tert‐butylcalix[4]arene diester with various amino alcohols. The transport of amino acid esters (phenylglycine, phenylalanine, and tryptophan methyl esters hydrochloride) and mandelic acid were studied through chloroform bulk liquid membrane system using chiral calix[4]arenes...
The amyloid fibril of bovine insulin and its renaturing intermediates were studied by using Raman optical activity (ROA). In the spectrum of the amyloid, the sharp +/− ROA couplet of amide I band characteristic of the β‐sheet‐rich proteins was observed, together with a sharp peak at 1271 cm−1 characteristic of a turn structure. The shoulder ROA peak of the native insulin at ∼ 1340 cm−1, which was...
In this study, two isomeric ruthenium(II) complexes [Ru(bpy)2(p‐mopip)]2+ (1) and [Ru(bpy)2(o‐mopip)]2+ (2) (bpy = 2, 2‐bipyridine; L: p‐mopip = 2‐(4‐methoxylphenyl) imidazo [4,5‐f][1,10]phenanthroline, o‐mopip = 2‐(2‐methoxylphenyl) imidazo[4,5‐f][1,10] phenan‐throline) contained OCH3 at different positions on the phenyl ring and their enantiomers 1, ‐2 and 1, ‐2 displayed different properties....
Preferential crystallization of amino acid derivatives by seeding a pure enantiomer into racemic amino acid solutions has been studied for many years. However, few examples of valine derivatives have been reported so far. Although there have been some reports using valine hydrogen chloride with preferential crystallization, it is difficult to obtain optical isomers for valine derivatives using preferential...
Cyclodextrins (CDs) possess a variety of chiral centers and are capable of recognizing enantiomeric molecules through the formation of inclusion complexes. Two types of CDs, α‐cyclodextrin (α‐CD) and β‐cyclodextrin (β‐CD), were selected to evaluate the effects of the enantioselective ecotoxicity of racemic metolachlor (Rac‐metolachlor) and its S‐enantiomer (S‐metolachlor) on the freshwater algae Scenedesmus obliquus...
The absolute stereochemistry of altersolanol A (1) was established by observing a positive exciton couplet in the circular dichroism (CD) spectrum of the C3,C4‐O‐bis(2‐naphthoyl) derivative 10 and by chemical correlations with known compound 8. Before the discussion, the relative stereochemistry of 1 was confirmed by X‐ray crystallographic analysis. The shielding effect at C7′‐OMe group by C1‐O‐benzoylation...
This article describes a study of the outcome of racemate condensation in different types of monolayers. The study was performed on a resorcinol surfactant bearing an octadecyl chain and a lactate group which formed a monolayer at the interface of graphite and 1‐phenyloctane as well as a Langmuir film at the air–water interface. Control experiments with the enantiopure materials provided the characteristics...
The distinctive nucleus of kainoid amino acids, (2S,3R)‐(+)‐2‐carboxypyrrolidine‐3‐acetic acid 6, was synthesized by a chemoenzymatic process, exploiting the diastereomeric cis/trans methyl pyroglutamate derivatives 10a, 10b, 10c/11a, 11b, 11c as key intermediates. These mixtures, when subjected to a kinetic resolution mediated by α‐chymotrypsin, reacted diastereo‐, regio‐, and enantioselectively...
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