In Sadagopan1, the errors were published on pages 7, 8, and in Table 1. On page 7, Section 3.2, where the article reads: The calculated pKa of 4 was 8.65, while that of the ammonium ion is known to be 9.3. Thus, showing it is favorable for ammonia to displace proline in the structure. An abundance of ammonia in the early atmosphere of Earth, can drive the production of 5. It should read: The calculated

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No abstract is available for this article.

No abstract is available for this article.

Cypermethrin (CP) is widely used for controlling agricultural and indoor vermin. Previous studies have reported the stereoselective difference of CP in biological activities. However, little is known about their potential mechanisms between metabolic phenotypes and endocrine‐disrupting effects. Herein, nuclear magnetic resonance (NMR)‐based metabolomics combining metabolite identification and pathway

Cloperastine is a central antitussive used to reduce the frequency and intensity of coughing on a short‐term basis. In this study, a reliable chiral LC‐MS/MS technology has been developed for the quantification of cloperastine enantiomers in the rat plasma. Carbinoxamine was selected as the internal standard. The enantioseparation of cloperastine was performed on a Chiralpak IA column with a mobile

Racemic ethyl 2,3‐dibromopropionate, commercially available at low price, is a key intermediate used in the synthesis of several heterocycle fragments, which are present in many biologically active compounds. Surprisingly, the enantiomers are not commercially available and have never been described in the literature. In this work, we undertook two different strategies to obtain these enantiomers, which

Chlorocyclopropanes (CCPs) conjugated to alk‐yn‐enes occur in a unique family of polyketide natural products from marine sponges. Synthesis of several optically enriched analogs of CCPs and measurement of their UV–vis spectra and electronic circular dichroism (ECD) spectra reveal unusually strong hyperconjugation that constrains and aligns the cyclopropyl C‐C bond with the π‐plane of the distal ene‐bond

Enantiomeric resolution and molecular docking studies of meclizine hydrochloride on polysaccharide‐based chiral stationary phase comprising cellulose tris(4‐methylbenzoate) chiral selector (150 × 4.6 mm, 3.0 μm) were presented. The mobile phase used was acetonitrile:10mM ammonium bicarbonate (95:05, v/v). The developed technique was used to perform the enantioselective assay of meclizine hydrochloride

The cover image is based on the Special Issue Article Plasmonic nanoparticles assemblies templated by helical bacteria and resulting optical activity by Wenchun Feng et al., https://doi.org/10.1002/chir.23225.

The cover image is based on the Regular Article Chiral separation of underivatized amino acids in supercritical fluid chromatography with chiral crown ether derived column by Larry Miller and Lei Yue, https://doi.org/10.1002/chir.23204.

No abstract is available for this article.

Citalopram (CIT) is a frequently used modern antidepressant that inhibits selectively serotonin reuptake in the brain. It has a chiral center in its structure and is used in therapy as both racemic mixture and pure enantiomer as its pharmacological effect is almost entirely associated with S‐CIT. The aim of this study was the development of a simple and rapid capillary electrophoresis (CE) method for

(R)‐1‐phenyl‐ethanol (PhEtOH) and the different isomers of (R)‐1‐(chlorophenyl)ethanol (ClPhEtOH) exhibit very interesting electronic circular dichroism (ECD) in methanol. In all cases, the spectrum shows clear vibronic features, but it is monosignated and negative for PhEtOH and meta‐ClPhEtOH, positive for the ortho isomer and bisignated for the para isomer. We used computational chemistry to rationalise

Professor William H. Pirkle (1934–2018) made a profound impact on modern chemistry by inventing and popularizing widely used techniques for the analysis and purification of enantiomers, contributions that paved the way for the subsequent advances in the discovery, development, and manufacture of enantiopure pharmaceuticals, agrochemicals, and specialty chemicals. Pirkle's pioneering 1966 demonstration

No abstract is available for this article.

Novel chiral selectors based on 3,5‐dimethyl phenylcarbamoylated β‐cyclodextrin connecting quinine (QN) or quinidine (QD) moiety were synthesized and immobilized on silica gel. Their chromatographic performances were investigated by comparing to the 3,5‐dimethyl phenylcarbamoylated β‐cyclodextrin (β‐CD) chiral stationary phase (CSP) and 9‐O‐(tert‐butylcarbamoyl)‐QN‐based CSP (QN‐AX). Fmoc‐protected

The vibrational circular dichroism (VCD) spectra of dicarvone (1), dipinocarvone (2), and dimenthol (3) have been recorded in the range 900–3200 cm−1, encompassing the mid‐infrared (mid‐IR), the CO stretching, and the CH‐stretching regions. For compound 3 also, the fundamental and the first overtone OH stretching regions have been investigated by IR/NIR absorption and VCD. Density functional theory

Interestingly, only the D‐form of firefly luciferin produces light by luciferin–luciferase (L–L) reaction. Certain firefly luciferin analogues with modified structures maintain bioluminescence (BL) activity; however, all L‐form luciferin analogues show no BL activity. To this date, our group has developed luciferin analogues with moderate BL activity that produce light of various wavelengths. For in

Malathion is a widely used chiral phosphorus insecticide, which has a more toxic chiral metabolite malaoxon. In this work, the enantiomers of malathion and malaoxon were separated by high‐performance liquid chromatography‐mass/mass (HPLC‐MS/MS) with chiral columns using acetonitrile/water or methanol/water as mobile phase, and the chromatographic conditions were optimized. Based on the chiral separation

The assembling behaviors of nonchiral dicationic amphiphilic molecules (gemini) in the presence of the mixture of chiral anionic nucleotides and nonchiral anions are investigated. We demonstrate that subtle balance of various physico‐chemical parameters and the competition between chiral and nonchiral anions at the interface of gemini assemblies influences the expression of molecular chirality at the

Direct enantioseparation of mandelic acid by high‐performance liquid chromatography (HPLC) with a reversed phase column and a mobile phase containing a small amount of hydroxylpropyl‐β‐cyclodextrin (HP‐β‐CD) was studied as an efficient method for saving consumption of the CD additive. As a result, it was proposed that racemic mandelic acid can be analyzed with a phenyl column by using a mobile phase

Resolution of enantiomers of chiral compounds via crystallization is the dominant method in chemical industry, but chiral recognition at the molecular level during this process is still poorly understood. Using single metal surfaces in ultrahigh vacuum as model system, the enantio‐related transition from the monolayer structure into a double layer of the racemic mixture of heptahelicene has been studied

In this paper, a novel l‐glutamate based immobilized chiral ionic liquid (SBA‐IL (Glu)) was prepared by chemical bonding method and applied as a solid sorbent for chiral separation of amlodipine. The performance of SBA‐IL (Glu) was investigated for the absorption of (S)‐amlodipine and separation of amlodipine enantiomer. The static experiment showed that equilibrium adsorption was achieved within 80

We present a new method based on optical null methods for simultaneously measuring the optical rotatory dispersion (ORD) and absorption spectra of chiral substances. The optical rotation angle at a specific wavelength can be obtained from the optical nulls of the Malus curves with and without the sample. We use the optical nulls of the two curves as benchmark points and the readings to the right of

Covalent organic frameworks (COFs) as a novel stationary phase have attracted much attention in the field of chromatography owing to their permanent nanoscale porosity, higher surface area, and exceptional stabilities. Here, a novel isocyanate‐β‐cyclodextrin‐modified COF (MDI‐β‐CD‐modified COF) was synthesized using isocyanate‐β‐cyclodextrin as the chiral selector and imine‐based TpPa‐1 COF as the

Plasmonic nanoparticles (NPs) adsorbing onto helical bacteria can lead to formation of NP helicoids with micron scale pitch. Associated chiroptical effects can be utilized as bioanalytical tool for bacterial detection and better understanding of the spectral behavior of helical self‐assembled structures with different scales. Here, we report that enantiomerically pure helices with micron scale of chirality

No abstract is available for this article.

(R)‐ricinoleic acid is the main component of castor oil from Ricinus communis L. Due to the presence of the hydroxyl group in homoallylic position and asymmetrically substituted carbon atom, it may undergo a number of chemical and biochemical transformations resulting in the products with some specific bioactivities. Conversion of (R)‐ricinoleic acid into its (S)‐enantiomer enables synthesis of both

A 1:1 mixture of pseudoenantiomer ethynylhelicene (P)‐pentamer and (M)‐tetramer in toluene formed hetero‐double‐helix and their self‐assembled gels. Kinetic analysis under isothermal conditions showed a complex nonlinear nature with regard to temperature changes. At 60°C, sigmoidal kinetics were observed, which disappeared after seeding with the self‐assembled gels. These findings indicate the involvement

Bridged bicyclic amino acids have high potential applicability as self‐organized, conformationally constrained synthetic building blocks that do not require assistance from hydrogen bond formation. We systematically investigated the intrinsic conformational propensities of dipeptides of bridged bicyclic β‐amino acids by means of accelerated molecular dynamics simulation and density functional theory

Two western red cedar pinoresinol‐lariciresinol reductase (PLR) homologues were studied to determine their enantioselective, substrate versatility, and kinetic properties. PLRs are downstream of dirigent protein engendered, coniferyl alcohol derived, stereoselective coupling to afford entry into the 8‐ and 8′‐linked furofuran lignan, pinoresinol. Our investigations showed that each PLR homolog can

Rapid derivatization of chiral 1,2‐diols with dinaphthyl borinic acid (DBA) leads to a cyclic boronate, enabling the absolute stereochemical prediction via exciton‐coupled circular dichroic (ECCD) of the naphthyl groups. Aryl‐ and alkyl‐substituted 1,2‐diols derivatized with DBA yield a predictable ECCD, which is also in agreement with theoretical predictions derived from computationally minimized

To investigate the impacts of the widely used chiral herbicide fenoxaprop‐ethyl (FE) on aquatic organisms, the enrichment, metabolism, acute toxicity, and oxidative stress of fenoxaprop‐ethyl and its main metabolites fenoxaprop (FA), ethyl‐2‐(4‐hydroxyphenoxy)propanoate (EHPP), 2‐(4‐hydroxyphenoxy)propanoic acid (HPPA), and 6‐chloro‐2,3‐dihydrobenzoxazol‐2‐one (CDHB) in zebrafish were studied. The

The magnetic circular dichroism (MCD) spectra of metal complexes of tetrakis(thiadiazole)porphyrazines ([TTDPzM] with M = 2HI, ZnII, MgII(H2O), and CdII) have been recorded in dimethyl formamide solution. Together with the UV–Vis spectra, the MCD spectra provide useful information about the structure and electronic properties of the complexes. The experimental UV–Vis and MCD spectra compare pretty

It has been recently shown that enantiomers of the helicoidal paddlewheel complex [Co3(dpa)4(CH3CN)2]2+ (dpa = the anion of 2,2′‐dipyridylamine) can be resolved using the chiral [As2(tartrate)2]2− anion (AsT) and that these complexes demonstrate a strong chiroptical response in the ultraviolet‐visible and X‐ray energy regions. Here we report that the nickel congener, [Ni3(dpa)4(CH3CN)2]2+, can likewise

4‐l‐menthyloxycarbonyl 5‐aryl prolinates were studied as organocatalysts of a novel three‐component reaction of cyclohexanone, benzoic acid, and β‐nitrostyrene. The presence of ortho‐halogen atom in 5‐aryl fragment of the catalyst is favored for driving the formation of chiral 7a‐hydroxyoctahydro‐2H‐indol‐2‐one scaffold. 5‐(o‐Chlorophenyl) prolinate selectively afforded 3‐phenyl‐7a‐hydroxyoctahydro‐2H‐indol‐2‐one

Vibrational Raman optical activity (ROA) spectra were calculated under off‐resonance, near‐resonance, and at‐resonance conditions for (A) and under off‐resonance conditions for (B) using a new driver software for calculating the ROA intensities from complex (damped) time‐dependent linear response Kohn‐Sham theory. The off‐resonance spectra of A and B show many similarities. At an incident laser wavelength

Moving from the simple concept that reflection onto a mirror surface changes the handedness of circularly polarized light, we describe what happens to the emergent polarization in two different cases after reflection on a back mirror. In the first case, a regular emitter is taken into account, where reflection has the effect to destroy the emergent polarization. In the second case, we show what could

The circular dichroism spectra of a single chain of polyfluorene was predicted for a p‐twisted helix conformation and local planarized polymer sections in the presence and in the absence of thermal vibrations. Under thermal vibrations at 300 K, the planarized section of polyfluorene affords a red‐shifted positive dichroic band between 446 and 456 nm, preserving a degree of chirality. The S1 ← S0 excitation