Search

GPU-accelerated on-the-fly nonadiabatic dynamics is enabled by interfacing the linearized semiclassical dynamics approach with the TeraChem electronic structure program. We describe the computational workflow of the "PySCES" code interface, a Python code for semiclassical dynamics with on-the-fly electronic structure, including parallelization over multiple GPU nodes. We showcase the abilities of this code and present timings for two benchmark systems: fulvene solvated in acetonitrile and a charge transfer system in which a photoexcited zinc-phthalocyanine donor transfers charge to a fullerene acceptor through multiple electronic states on an ultrafast timescale. Our implementation paves the way for an efficient semiclassical approach to model the nonadiabatic excited state dynamics of complex molecules, materials, and condensed phase systems. [ABSTRACT FROM AUTHOR]

The study involved the determination of the equilibrium mole fraction solubility of sildenafil citrate in aqueous binary mixtures of acetonitrile across a range of temperatures (from 293.15 K to 313.15 K). To represent this data numerically, both linear and non-linear cosolvency models were employed, and their performances were assessed through mean relative deviations or MRD%. Additionally, this study calculated the apparent thermodynamic properties (Gibbs energy, entropy, and enthalpy) for the dissolution processes using the van’t Hoff and Gibbs equations. Moreover, the study determined the density values of sildenafil citrate saturated solutions and presented them through the van’t Hoff equation. [ABSTRACT FROM AUTHOR]

The electrocatalytic dehydrogenation of ethylamine (EDH), owing to its high hydrogen content, holds broad prospects in electrochemical hydrogen (H2) production, H2 storage, and addressing energy issues, thus deserving wide attention. In this feature article, we first summarized the fundamentals of thermocatalytic and electrocatalytic EDH and reviewed the recent state-of-the-art advances in catalyst research, specifically platinum group metal (PGM) catalysts and non-PGM catalysts. We systematically discussed the potential applications of electrocatalytic EDH in energy storage and conversion. Finally, we provide our perspective on the key challenges and future developments in this field. We believe this feature article will offer helpful guidance for oriented design and optimization of stable and efficient catalysts for electrocatalytic EDH and related energy applications. [ABSTRACT FROM AUTHOR]

Summary: Rosemary extract (RE) is a natural antioxidant, which has been widely used for preservation of oils. The main lipophilic components of RE are carnosic acid (CA) and carnosol (CN). However, the reports on the method for determining CA and CN in vegetable oils are really rare. Herein, a highly efficient method for quantitative analysis of CA and CN in vegetable oils was developed. The vegetable oil samples were dissolved in n‐hexane saturated using acetonitrile and extracted with acetonitrile saturated using n‐hexane, followed by HPLC analysis using UV detector. Qualitative and quantitative determinations were performed by external standard method. Under the optimised conditions, limit of detection (LOD) and limit of quantitation (LOQ) of CA were 0.11 μg mL−1 and 0.55 μg mL−1, respectively; LOD and LOQ of CN were 0.05 μg mL−1 and 0.20 μg mL−1, respectively. When the method was applied to determine CA and CN in vegetable oils spiked with standards, good recoveries (83.98% ~ 102.80% for CA and 98.29% ~ 114.74% for CN) and RSDs (0.61% ~ 7.36% for CA and 0.40% ~ 2.88% for CN, n = 2) were achieved. Accordingly, this work would efficiently identify and monitor lipophilic RE in vegetable oils, as this advanced method showed sensitive, quantitative, and reliable results suited for vegetable oils. [ABSTRACT FROM AUTHOR]

We established an efficient analytical approach for simultaneous determination of benthiavalicarb-isopropyl and its four metabolites (KIF-230-M1, KIF-230-M3, KIF-230-M4, and KIF-230-M5) in fruits and vegetables. Samples were extracted with acidified acetonitrile, with octadecylsilane and graphitised carbon black as sorbent for clean-up, and UHPLC-MS/MS for determination. The approach was determined at spikes of 5, 50, and 500 μg kg−1. The recoveries of the six matrices analyzed ranged from 74.5% to 115.6% with 0.5–12.6% for intra-day RSDr (n = 5), and 0.4–13.8% for inter-day RSDR (n = 15). The five analytes in all matrices achieved high linearity (R2 > 0.9917). The limit of quantification (LOQ) of benthiavalicarb-isopropyl as well as its four metabolites in all matrices was 5 μg kg−1. This analytical approach allows for monitoring residues of benthiavalicarb-isopropyl and its metabolites in vegetables and fruits. [ABSTRACT FROM AUTHOR]

Quaternary ammonium salts (QASs) have been used as antimicrobial agents, surfactants, and ionic liquids in electrical double-layer capacitors, rechargeable lithium-ion batteries, and dye-sensitized solar cells. It is well known that solvents and reactants strongly affect the Menshutkin reaction. However, QASs are potentially harmful to humans and the environment. To address these issues, we report the effects of solvent polarity on the thermochemistry of two selected Menshutkin reactions, (1) trimethylamine and 1-iodopropane yielded propyltrimethylammonium, and (2) methylacetamide and 1-iodopropane yielded acetylpropylmethylammonium. We systematically constructed possible QAS unique conformers within the first-principles framework in solvents that have three various polarities: toluene, acetonitrile, and water. The polar solvent shifted both reactions toward exergonic and decreased the Gibbs free activation energy. In addition, the polar solvent changed the favorable reaction for the acetylpropylmethylammonium formation only due to an intramolecular hydrogen bond. Therefore, we suggest that selecting high solvent polarity should be considered to address the potential health and environmental effect. [ABSTRACT FROM AUTHOR]

Residues of the fungicides difenoconazole, propiconazole, cyflufenamid, and mandipropamid were determined in tomato fruit using acetonitrile for extraction and LC-MS/MS for quantification. Validation criteria include linearity range, the limit of detection (LOD) and limit of quantitation (LOQ), accuracy in terms of precision and trueness, and matrix effect were studied. The recovery rates of the method ranged from 91.8 to 106.3%. The precision of the method in terms of repeatability at one day (RSDr) and between three days (RSDR) ranged from 2.8 to 6.4% and from 4.3 to 7.6%, respectively, with good trueness from 92.2 to 96.4%. Matrix effects (suppression effects) ranged from 3.8% to 11.1%. The validated method was used to evaluate the dissipation kinetics of three different premix formulations: 30% EC (15% difenoconazole + 15% propiconazole), 14% DC (12.5% difenoconazole + 1.5% cyflufenamid), and 50% SC (25% difenoconazole + 25% mandipropamid) used on field tomatoes in Egypt. A first-order kinetic equation best describes residue dissipation. The calculated half-lives of difenoconazole, propiconazole, cyflufenamid, and mandipropamid were 2.01–2.27, 1.89, 1.97, and 1.71 days, respectively. The dissipation rate of difenoconazole did not differ significantly in the three premix formulations. Mandipropamid also dissipated faster compared to the other fungicides tested. The chronic dietary risk assessment results showed a minimal risk to adult Egyptian consumers. Waiting periods were advised for the safe consumption of tomatoes treated with the tested premix formulations. [ABSTRACT FROM AUTHOR]

An ultra-rapid analytical method for determination of andrographolide and dehydroandrographolide in Andrographis Herba (AH) was developed by liquid chromatography with mass spectrometry (LC-MS). The sample was ultrasonically extracted with 10 mL 40% (v/v) methanol, and then purified with a C18 solid phase extraction column. The LC separation was performed on a Poroshell 120 EC-C18 column (30 × 2.1 mm, 2.7 μm) and eluted with 0.5 mmol L−1 ammonium acetate aqueous solution and acetonitrile (65:35) at a flow rate of 0.7 mL min−1, and detected by mass spectrometry (MS). The LC-MS analytical time was less than 1 min. The new developed method presented a good linearity (r > 0.9900), precision and repeatability (RSD < 2.0%). The recoveries for andrographolide and dehydroandrographolide were 93.5% (RSD = 2.2%) and 97.7% (RSD = 2.4%), respectively. The developed method was successfully applied in determination of andrographolide and dehydroandrographolide in seven batches of AH samples, and the contents of analytes in all samples were complied with the relative acceptance criteria in Chinese Pharmacopeia (>0.8%). This new developed LC-MS method is an ultra-rapid assay method for AH, which will help to improve the efficiency and reduce the cost of AH sample test. [ABSTRACT FROM AUTHOR]

A novel simple and cost effective HPLC technique was presented for the quantification of selexipag (SLP) in human plasma sample and the technique's applicability to a pharmacokinetic investigation. Chromatographic separation was achieved with C18 (5 µm × 4.6 mm × 150 mm) column, at 30 °C with isocratic elution, mobile phase composed of solution A (acetonitrile), and solution B (0.5% formic acid) (65:35 v/v) at flow rate 1.2 mL min−1. The linearity range is 10–150 ng mL−1. As sample preparation step human plasma was precipitated with acetonitrile and the detection was provided at 300 nm. The retention time is 8.20 ± 0.02 min. LOD is found to be 3.3 ng mL−1 for drug. The method was applied to the analysis of SLP in human plasma with good recovery as 97.83%. Validation of the studied methods was carried out according to EMA guideline. The new method applied on a prototype pharmacokinetic study by administration of 800 μg SLP to a healthy volunteer and parameters like AUC0–24, AUC0–∞, Cmax, tmax, and t1/2 were assessed. [ABSTRACT FROM AUTHOR]

Intramolecular charge transfer (ICT) effects of para‐nitroaniline (pNA) in eight solvents (cyclohexane, toluene, acetic acid, dichloroethane, acetone, acetonitrile, dimethylsulfoxide, and water) are investigated extensively. The second‐order algebraic diagrammatic construction, ADC(2), ab initio wave function is employed with the COSMO implicit and discrete multiscale solvation methods. We found a decreasing amine group torsion angle with increased solvent polarity and a linear correlation between the polarity and ADC(2) transition energies. The first absorption band involves π → π* transitions with ICT from the amine and the benzene ring to the nitro group, increased by 4%–11% for different solvation models of water compared to the vacuum. A second band of pNA is characterized for the first time. This band is primarily a local excitation on the nitro group, including some ICT from the amine group to the benzene ring that decreases with the solvent polarity. For cyclohexane, the COSMO implicit solvent model shows the best agreement with the experiment, while the explicit model has the best agreement for water. [ABSTRACT FROM AUTHOR]

Levosulpiride and omeprazole are co-prescribed for gastrointestinal disorders associated with depression and anxiety. Objective of the study was to develop a sensitive, robust and simple method for simultaneous analysis of levosulpiride and omeprazole in human plasma and applicability of the method in determination of pharmacokinetics drug-drug interaction. In the presented study, a reversed-phase HPLC-UV method was developed for the simultaneous determination of levosulpiride and omeprazole using pantoprazole as the internal standard. Experimental conditions were optimized and the developed method was validated as per standard guidelines (USP and ICH). Furthermore, the developed method was applied for evaluation of pharmacokinetics drug-drug interaction between levosulpiride (50 mg) and omeprazole (40 mg) in healthy human volunteers. Sharpsil C8 column (4.6 × 250 mm, 5 μm), Ultisil C8 column (4.6 mm × 150 mm, 5 μm) and Agilent C18 column (4.6 × 250 mm, 5 μm) were evaluated as stationary phase. The best resolution was achieved with Agilent C18 (4.6 x 250 mm, 5 μm) column and was selected for further study. The mobile phase consisted of a mixture of acetonitrile and phosphate buffer (pH 7.2) in 60:40 by volume, and was pumped at a flow rate of 1 mL/min. Detector wavelength was set at 280 nm. Levosulpiride and omeprazole were extracted from human plasma with ethyl acetate and dichloromethane (4:1, v/v). The calibration curves for both levosulpiride (5–150 ng/mL) and omeprazole (10–1500 ng/mL) were linear. The lower limit of quantification and limit of detection for levosulpiride were 5 and 2 ng/mL, while for omeprazole these were 10 and 3 ng/mL, respectively. Pharmacokinetics analysis showed that co-administration of omeprazole increased the AUC and Cmax of levosulpiride, while the clearance was reduced. Both the changes were insignificant. Similarly, no significant change in the pharmacokinetic parameters of omeprazole was observed with co-administration of levosulpiride. [ABSTRACT FROM AUTHOR]

AbstractThe complex bis(acetonitrile)bromido(η6-1-isopropyl-4-methylbenzene)osmium(II) hexafluoroantimonate, [OsBr(C10H14)(CH3CN)2]SbF6 (1) crystallizes as a triclinic system in space group P1 (no. 2), consisting of two cationic osmium(II) complex ions and two anionic hexafluoroantimonate counterions in each cell. Density Functional Theory (DFT) calculations were performed at the B3LYP/LanL2DZ and B3LYP/Def2 − SVP/Def2 − TZVP levels of theory. Reactivity descriptors and charge transfer properties were computed using frontier molecular orbital analysis. The DFT-optimized model systems from both basis sets were comparable to the experimentally determined X-ray diffraction results. Hirshfeld surface analysis shows significant non-covalent interactions including hydrogen bonds and halogen interactions. The MTT technique was utilized to conduct an in vitro cytotoxicity assay of 1 against cancerous cell lines (MCF-7 and A549) and normal cells (HEK293). Complex 1 is potent towards cancer cells as evidenced by the IC50 values of 5.02 ± 0.05 µM for MCF-7 cells and 13.36 ± 0.04 µM for A549 cells. Complex 1 demonstrated lower toxicity to normal cells with an IC50 value of 26.76 ± 0.08 µM for the HEK293 cell line compared to the doxorubicin standard with an IC50 value of 1.2 ± 0.1 µM. [ABSTRACT FROM AUTHOR]

The energy storage capability of supercapacitors (SCs) strongly depend on the operating cell voltage of the electrolytes of choice. In this regard, the inherent distinct electrochemical stability of cations and anions is a factor of relevance for the operating cell voltage. The use of double salts sharing one ion has been described as an approach to circumvent this problem, but whether modifying the solvation structure of cations and anions with different solvent molecules (coordinating and/or non‐coordinating) could help balance their electrochemical stability in SCs has not yet been fully addressed. In this work, electrolytes are prepared by combining solvent mixtures and double salts, specifically 1‐ethyl‐3‐methylimidazolium bis(trifluoromethylsulfonyl)imide (EMIMTFSI) and 1‐ethyl‐3‐methylimidazolium tetrafluoroborate (EMIMBF4) in mixtures of water (H2O) and dimethysulfoxide (DMSO) as coordinating co‐solvents and acetonitrile (CH3CN) as a weakly coordinating one. It is found that the presence of this latter one helped to enhanced the cation solvation structure (above 9). This increase of the entropic features allows operating at cell voltages of up to 2.2 V and the subsequent enhancement of the energy storage capabilities and capacitance retentions (up to 15 Wh kg−1 and ≈87% after 10 000 cycles, respectively). [ABSTRACT FROM AUTHOR]

Background: Trifarotene is effective for treating acne and other skin issues. To ensure its quality and meet regulatory standards, a reverse phase liquid chromatography (RP-LC) stability-indicating method was developed and validated for its quantification in pure and topical dosage forms. An isocratic elution chromatographic method was employed, using an octadecylsilyl silica gel-packed column (150 mm × 4.6 mm, 3 µm particle size). The mobile phase was a mixture of phosphate buffer and acetonitrile (40:60 v/v). Chromatographic conditions included a flow rate of 0.5 mL/min, column temperature of 40 °C, detection at 265 nm, and injection volume of 20 µL. Results: The developed analytical method reports the retention time of trifarotene 11.2 min, higher theoretical plate count, asymmetric peak, and good resolution between the peaks of trifarotene, phenoxyethanol, and environmentally generated impurities. Conclusion: The analytical method has been found to be linear, accurate, robust, specific, and selective for impurities produced during forced degradation studies. The proposed analytical method can be utilized for routine pharmaceutical analysis of trifarotene to judge its quality and safety. [ABSTRACT FROM AUTHOR]

An X-ray analysis of exfoliated MoS2, produced by means of microwave-assisted liquid-phase exfoliation (LPE) from bulk powder in 1-methyl-2-pyrrolidone (NMP) or acetonitrile (ACN) + 1-methyl-2-pyrrolidone (NMP) solvents, has revealed distinct structural differences between the bulk powder and the microwave-exfoliated samples. Specifically, we performed X-ray diffraction (XRD) and X-ray photoelectron spectroscopy (XPS) measurements to identify the elements of our exfoliated sample deposited on a Si substrate by drop-casting, as well as their chemical state and its structural crystalline phase. In the exfoliated sample, the peaks pattern only partially resemble the theoretical Miller indices for MoS2. In contrast, the bulk powder's spectrum shows the characteristic peaks of the 2H polytype of MoS2, but with some broadening. Notable is the retention of partial crystallinity in the post-exfoliation phases, specifically in the normal-to-plane orientation, thus demonstrating the effectiveness of microwave-assisted techniques in producing 2D MoS2 and attaining desirable properties for the material. XPS measurements confirm the success of the exfoliation procedure and that the exfoliated sample retains its original structure. The exfoliation process has been optimized to maintain the structural integrity of MoS2 while enhancing its surface area and electrochemical performance, thereby making it a promising material for advanced electronic and optoelectronic applications ranging from energy storage to sensing devices under ambient conditions. [ABSTRACT FROM AUTHOR]

Photoactive N-hydroxysulfonamides photocaged with the (6-bromo-7-hydroxycoumarin-4-yl)methyl chromophore have been successfully synthesized, and the mechanisms of photodecomposition investigated for two of the compounds. Upon irradiation up to 97% of a diagnostic marker for (H)NO release, sulfinate was observed for the trifluoromethanesulfonamide system. In the absence of a species that reacts rapidly with (H)NO, (H)NO instead reacts with the carbocation intermediate to ultimately generate (E)-BHC-oxime and (Z)-BHC-oxime. Alternatively, the carbocation intermediate reacts with solvent water to give a diol. Deprotonation of the N(H) proton is required for HNO generation via concerted C-O/N-S bond cleavage, whereas the protonation state of the O(H) does not affect the observed photoproducts. If the N(H) is protonated, C-O bond cleavage to generate the parent N-hydroxysulfonamide will occur, and/or O-N bond cleavage to generate a sulfonamide. The undesired competing O-N bond cleavage pathway increases when the volume percentage of water in acetonitrile/water solvent mixtures is increased. [ABSTRACT FROM AUTHOR]

[(Bn-tpen)FeII(MeCN)](ClO4)2, containing the pentadentate Bn-tpen–N-benzyl-N,N′,N′-tris(2-pyridylmethyl)-1,2-diaminoethane ligand, was studied in the oxygenation of cyclohexene and limonene using low-pressure dioxygen (0.2 atm air or 1 atm pure O2) in acetonitrile. 2-Cyclohexen-1-one and 2-cyclohexen-1-ol are the main products of cyclohexene oxidations, with cyclohexene oxide as a minor product. Limonene is oxidized to limonene oxide, carvone, and carveol. Other oxidation products such as perillaldehyde and perillyl alcohol are found in trace amounts. This catalyst is slightly less active than the previously reported [(N4Py)FeII(MeCN)](ClO4)2 (N4Py–N,N-bis(2-pyridylmethyl)-N-(bis-2-pyridylmethyl)amine). Based on cyclic voltammetry experiments, it is postulated that [(Bn-tpen)FeIV=O]2+ is the active species. The induction period of approx. 3 h during cyclohexene oxygenation is probably caused by deactivation of the reactive Fe(IV)=O species by the parent Fe(II) complex. Equimolar mixtures of Fe(II) salt and the ligand (in situ-formed catalyst) gave catalytic performance similar to that of the synthesized catalyst. [ABSTRACT FROM AUTHOR]

A base-induced synthesis of 2-(4-(2-(phenylthio)ethyl)piperazinyl) acetonitriles by reaction of disulfides, 1-(chloromethyl)-4-aza-1-azonia bicyclo[2.2.2]octane chloride and trimethylsilyl cyanide is reported. The scope of the method is demonstrated with 30 examples. The reaction mechanism research indicates that the three-component reaction would be a SN2 reaction. The products exhibit good activities towards advanced synthesis of aqueous soluble acyl-CoA: cholesterol O-acyltransferase-1 (ACAT-1) inhibitors. Our work is superior as it uses less-odor disulfides as carbon sources and EtOH as solvent in a water and dioxygen insensitive reaction system, followed by a simple purification process. [ABSTRACT FROM AUTHOR]

Copyright of Shipin Kexue/ Food Science is the property of Food Science Editorial Department and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

KPT-335 (Verdinexor) is a novel SINE that potently inhibits the nucleoprotein Exportin 1 (XPO1/CRM1) of tumor cell lines and reduces the replication level of the influenza virus. KPT-335 is mainly used for the treatment of canine tumors. Drugs for the effective treatment of feline tumors are currently unavailable in China. KPT-335 may have potential in the treatment of cat tumors. However, the effects of KPT-335 in cats are unreported, and no relevant methodology has been established for pharmacokinetic studies. In this study, a UPLC-MS/MS method was developed to determine KPT-335 concentrations in cat plasma, followed by pharmacokinetic studies. Briefly, plasma proteins are precipitated with acetonitrile, and the supernatant was collected for detection after centrifugation. The linearity for KPT-335 in cat plasma was in the range of 5-1,000 ng/mL. Satisfactory accuracy and precision were obtained. The intra-day accuracy was between -4.10% and 10.48%, the precision was =4.65%; the inter-day accuracy was between -0.11% and 8.09%, and the precision was =5.85%. Intra-day and inter-day accuracy and precision were within regulatory limits. The results of preliminary pharmacokinetic studies were as follows: Tmax was 1.46 ± 0.51 h; Cmax was 239.54 ± 190.60 ng·mL-1; T1/2 was 5.16 ± 2.30 h; AUC0-t was 1439.85 ± 964.64 ng·mL-1·h. The AUC0-8 was 1589.82 ± 1003.75 ng·mL-1·h. The purpose of this study was to develop a rapid and simple UPLC-MS/MS method to detect KPT-335 concentration in cat plasma and to conduct preliminary pharmacokinetic studies to support the future application of KPT-335 in felines. [ABSTRACT FROM AUTHOR]

Crystallisation of anthraquinone substituted p-tert-butylthiacalix[4]arene in the partial cone conformation from a range of solvents led to the isolation of two solvates, containing a mixture of chloroform and acetonitrile (PC1a) or toluene (PC1d) molecules, the structures of which were uncovered by SCXRD studies. Upon heating, the former solvate undergoes a single-crystal-to-single-crystal transformation, leading to removal of the acetonitrile molecules from the host and repositioning of the chloroform molecules (PC1b). This is connected with rearrangements of the non-covalent interactions, nicely reflected by a change in the hydrogen bond acceptor of the weak C–H⋯O hydrogen bonds. The transformation process is reversible, as confirmed by exposure of the crystal to acetonitrile vapour. Furthermore, the guest free phase of PC1 was obtained by melt crystallisation (PC1c). [ABSTRACT FROM AUTHOR]

Herein, we have isolated new 20-membered macrocycles by the simple condensation of α,α-dihalo-β-oxoaldehydes with diaminofurazan in acetonitrile. The interior and exterior sites of these macrocycles comprise hydrogen and halogen bond donor sites, respectively. Depending on the electron donating or accepting character of the substituents at the exterior sites of macrocyclic scaffolds, the average cavity diameters range from 8.15 to 8.47 Å. [ABSTRACT FROM AUTHOR]

Cis‐5,15‐bis(3,5‐trifluoromethylphenyl)calix[4]pyrrole (1) forms stable 1/1 complexes with linear anions such as N3−, SCN− and NCO‐ with the highest affinity for NCO− anion in acetonitrile solution. Crystallization of receptor 1 with TBASCN and (TMA)2SO4 resulted in the formation of dimeric capsular assembly, {(TMA)2[12 ⋅ (SCN)2]}, in which two thiocyanate anions are encapsulated. On the other hand, 1 ⋅ OCN(TMA) and 1 ⋅ N3(TMA) complexes form one dimensional columnar structure in the solid state. [ABSTRACT FROM AUTHOR]

Octadecylamine (ODA) is the most widely used film‐forming amine in the nuclear industry. Its function is to minimize corrosion. In this work, we developed and validated a liquid chromatography‐mass spectrometry method that allows the quantification of ODA in the presence of other amines in the secondary system of nuclear power plants operating under all‐volatile treatment chemistry. Sample stabilities greater than 95% were achieved after 1 week of being taken in acetonitrile 1:1. The method showed a high selectivity allowing the measurement of ODA in the presence of other amines. The calibration curve was linear in the range of 0.0025–0.1025 mg/L. The limit of detection and limit of quantification (LOQ) were 1.8 and 2.2 µg/L, respectively for an injection volume of 3 µL. Lower LOQs can be achieved by increasing the injection volume, making the method applicable even in the first hours and days of treatment. The bias of the method was less than 10% and the relative standard deviation of reproducibility was less than 15%. The sample stabilization was robust and the uncertainty associated with the method was acceptable. The method was applied to a real sample taken after a few years of treatment and a concentration of 0.15 mg/L was measured. [ABSTRACT FROM AUTHOR]

Simultaneous determination of a tandem of drugs like perindopril and rosuvastatin with differences in water and organic solvent solubilities, hydrophobicity, polarities, and UV‐absorbing possibilities between them necessitates careful selection of chromatographic conditions. The four specified and different bonded reversed‐phase columns were tested with running mobile phases containing various composition contents concepts; the concept of using diluted trifluoroacetic acid in mobile phase composition with acetonitrile enabled simultaneous acidification and weak ion‐pairing with protonized molecules of analytes, yielding appropriate, short, reasonable run times and resolutions of analytes, satisfying UV‐transparency, and good peak symmetries. These facts especially stand for the peak of perindopril, as a member of the group of proline‐containing moiety in its structure, often and easily prone to peak‐tailing, skewing, or splitting on the high‐performance liquid chromatography chromatograms, which is usually solved by using alkyl‐sulfonate base and ion pairs on higher concentrations of buffering salts with low pH values and with column temperatures increasing by 50°C–60°C. Linearity range was 0.002/004–0.5 mg/mL. The score for method AGREE was 0.73–0.77. The method development approaches, with all columns employing our concepts in mobile phases and experimental conditions, can cover the complete needs and demands of quality control departments and laboratories as simple high‐throughput analysis methods. [ABSTRACT FROM AUTHOR]

Perovskite solar cells (PSCs) have demonstrated remarkable progress in performance in recent years, which has placed perovskite materials as the leading promising materials for future renewable energy applications. The solvent additive technique in perovskite composition is a simple but effective process used to improve the surface quality of the perovskite layers and to improve the performance and charge transport processes essential to the functions of PSCs. These additives can have a considerable effect on the topography, crystallinity, and surface properties of the perovskite active layer, ultimately influencing the stability of the PSCs. A "two-step spin coating" deposition method to make PSCs in ambient air laboratory conditions was employed. Acetonitrile (ACN) was conventionally utilized as a chemical additive to enhance the performance of PSCs. In this study, our film properties exhibited that the incorporation of ACN in the triple cation perovskite precursor led to the passivation of surface defects and a noticeable increase in the size of the crystal grains of the perovskite films, which led to enhanced stability of devices. The efficiency achieved for PSCs prepared with 10% ACN was 15.35%, which is 30% higher than devices prepared without ACN. In addition, devices prepared with ACN have shown a lower hysteresis index and more stable behavior compared to devices prepared without ACN. This work presents an easy, low-cost method for the fabrication of high performance PSCs prepared under ambient air laboratory conditions. [ABSTRACT FROM AUTHOR]

Introduction: This study employs Proton-Transfer-Reaction Mass Spectrometry (PTR-MS) to analyze exhaled breath profiles of 504 healthy adults, focusing on nine common volatile organic compounds (VOCs): acetone, acetaldehyde, acetonitrile, ethanol, isoprene, methanol, propanol, phenol, and toluene. PTR-MS offers real-time VOC measurement, crucial for understanding breath biomarkers and their applications in health assessment. Objectives: The study aims to investigate how demographic factors-gender, age, and smoking history-affect VOC concentrations in exhaled breath. The objective is to enhance our understanding of breath biomarkers and their potential for health monitoring and clinical diagnosis. Methods: Exhaled breath samples were collected using PTR-MS, measuring concentrations of nine VOCs. The data were analyzed to discern distribution patterns across demographic groups. Results: Males showed higher average VOC levels for certain compounds. Propanol and methanol concentrations significantly increased with age. Smoking history influenced VOC levels, with differences among non-smokers, current smokers, and ex-smokers. Conclusion: This research provides valuable insights into demographic influences on exhaled VOC profiles, emphasizing the potential of breath analysis for health assessment. PTR-MS's real-time measurement capabilities are crucial for capturing dynamic VOC changes, offering advantages over conventional methods. These findings lay a foundation for advancements in non-invasive disease detection, highlighting the importance of considering demographics in breath biomarker research. [ABSTRACT FROM AUTHOR]

The acetonitrile AgIII complex [AgIII(CF3)3(NCCH3)] (2) has been reported independently by Eujen and Naumann in the last century, albeit with intriguing NMR discrepancy. In their reports, 2 was claimed to be obtained starting from either [AgIII(CF3)3Cl]− (3⋅Cl) or [AgIII(CF3)4]− (1) via halide abstraction using AgNO3 or acidic treatment, resp. These two synthetic routes are herein reinvestigated. The feasibility of Naumann's method is demonstrated, thus providing 2 yet accompanied by its s‐triazinyl derivative [AgIII(CF3)3(C6H9N3)] (2'). The formation of 2' is unprecedented and was thereby investigated. Both 2 and 2' were isolated in pure fashion and fully characterized. In turn, halide extraction from 3⋅Cl leads to the AgIII‐ONO2 anion 5 instead of 2, as evidenced by NMR spectroscopy, EA and Sc‐XRD. [ABSTRACT FROM AUTHOR]

Context: 1,3-Dithiole-2-thione-4,5-dithiolate (dmit) ligands are known for their conductive and optical properties. Dmit compounds have been assessed for use in sensor devices, information storage, spintronics, and optical material applications. Associations with various metallic centers endow dmit complexes with magnetic, optical, conductive, and antioxidant properties. Optical doping can facilitate the fabrication of magnetic conductor materials from ground-state nonmagnetic cations. While most studied complexes involve transition-metal centers due to their diverse chemistry, compounds with representative elements are less explored in the literature. This study investigated the structural and electronic properties of bisdmit complexes with representative Bi(III), Sb(III), and Zn(II) cations. AIMD calculations revealed two new geometries for Bi(III) and Zn(II) complexes, diverging from the isolated geometry typically used in quantum chemical calculations. The coordination of acetonitrile molecules to the cationic centers of the complexes resulted in unstable structures, while the dimerization of the complexes was stable. SA-CASSCF/NEVPT2 calculations were applied to the structures of the isolated complexes and stable dimers, confirming the multireference character of the electronic structure of the three systems and the multiconfigurational character of the Bi(III) complex. The electronic spectra simulated by the STEOM-DLPNO-CCSD calculations accurately reproduced the experimental UV‒Vis spectra indicating the participation of the isolated Bi(III) dmit complex and its dimeric form in solution. Methodology: AIMD calculations of the dmit salts were conducted using the GFN2-xTB method with 60 explicit acetonitrile molecules as the solvent at 300 K for a total simulation time of 50.0 ps, with printing intervals of 0.5 fs. The final geometries were optimized employing the PBEh-3c compound method, incorporating implicit conductor-like polarizable continuum model (CPCM) solvation for acetonitrile. Local energy decomposition (LED) analysis at the DLPNO-CCSD(T)/Def2-TZVP level of theory was utilized to investigate the stability of the complex geometries identified by AIMD. The electronic structures of the complexes were assessed using the SA-CASSCF/NEVPT2/Def2-TZVP method to confirm the multiconfigurational and multireference nature of their electronic structures. Electronic spectra were analyzed using the STEOM-DLPNO-CCSD/Def2-TZVP method, with CPCM used to simulate an acetonitrile medium. [ABSTRACT FROM AUTHOR]

Pollen collected by pollinators can be used as a marker of the foraging behavior as well as indicate the botanical species present in each environment. Pollen intake is essential for pollinators' health and survival. During the foraging activity, some pollinators, such as honeybees, manipulate the collected pollen mixing it with salivary secretions and nectar (corbicular pollen) changing the pollen chemical profile. Different tools have been developed for the identification of the botanical origin of pollen, based on microscopy, spectrometry, or molecular markers. However, up to date, corbicular pollen has never been investigated. In our work, corbicular pollen from 5 regions with different climate conditions was collected during spring. Pollens were identified with microscopy-based techniques, and then analyzed in MALDI-MS. Four different chemical extraction solutions and two physical disruption methods were tested to achieve a MALDI-MS effective protocol. The best performance was obtained using a sonication disruption method after extraction with acetic acid or trifluoroacetic acid. Therefore, we propose a new rapid and reliable methodology for the identification of the botanical origin of the corbicular pollens using MALDI-MS. This new approach opens to a wide range of environmental studies spanning from plant biodiversity to ecosystem trophic interactions. [ABSTRACT FROM AUTHOR]

Recently, our group has shown that fentanyl and many of its analogues form prototropic isomers ("protomers") during electrospray ionization. These different protomers can be resolved using ion mobility spectrometry and annotated using mobility‐aligned tandem mass spectrometry fragmentation. However, their formation and the extent to which experimental variables contribute to their relative ratio remain poorly understood. In the present study, we systematically investigated the effects of mixtures of common chromatographic solvents (water, methanol, and acetonitrile) and pH on the ratio of previously observed protomers for 23 fentanyl analogues. Interestingly, these ratios (N‐piperidine protonation vs. secondary amine/O = protonation) decreased significantly for many analogues (e.g., despropionyl ortho‐, meta‐, and para‐methyl fentanyl), increased significantly for others (e.g., cis‐isofentanyl), and remained relatively constant for the others as solvent conditions changed from 100% organic solvent (methanol or acetonitrile) to 100% water. Interestingly, pH also had significant effects on this ratio, causing the change in ratio to switch in many cases. Lastly, increasing conditions to pH ≥ 4.0 also prompted the appearance of new mobility peaks for ortho‐ and para‐methyl acetyl fentanyl, where all previous studies had only showed one single distribution. Because these ratios have promise to be used qualitatively for identification of these (and emerging) fentanyl analogues, understanding how various conditions (i.e., mobile phase selection and/or chromatographic gradient) affect their ratios is critically important to the development of advanced ion mobility and mass spectrometry methodologies to identify fentanyl analogues. [ABSTRACT FROM AUTHOR]

In the present investigation, a total of 108 combinations of ionic liquids (ILs) were screened using the conductor-like screening model for real solvents (COSMO-RS) with the aid of six cations and eighteen anions for the extraction of succinic acid (SA) from aqueous streams through dispersive liquid–liquid microextraction (DLLME). Using the screened ILs, an ionic liquid-based DLLME (IL-DLLME) was developed to extract SA and the role of different reaction parameters in the effectiveness of IL-DLLME approach was investigated. COSMO-RS results suggested that, quaternary ammonium and choline cations form effective IL combinations with [OH¯], [F¯], and [SO42¯] anions due to hydrogen bonding. In view of these results, one of the screened ILs, tetramethylammonium hydroxide [TMAm][OH] was chosen as the extractant in IL-DLLME process and acetonitrile was adopted as the dispersive solvent. The highest SA removal efficiency of 97.8% was achieved using 25 μL of IL [TMAm][OH] as a carrier and 500 μL of acetonitrile as dispersive solvent. The highest amount of SA was extracted with a stir time of 20 min at 300 rpm, followed by centrifugation for 5 min at 4500 rpm. Overall, the findings showed that IL-DLLME is efficient in extracting succinic acid from aqueous environments while adhering to the first-order kinetics. [ABSTRACT FROM AUTHOR]

The current comprehensive review covers four main parts, of which some are presented in the form of a personal account. 1. Anodic oxidation of a) N‐alkyl and N,N‐diallyl carbonyl moieties, b) Azacycloalkyl amides and the effect of ring‐size on the outcome, c) Lactams, d) Sulfonamides, and e) The effect of a substituent R attached to carbonyl (N−CO−R) or sulfonamides (N−SO2R) on their oxidation potentials. 2. Anodic oxidation of aromatic amides, in particular of type Ph2CHCONHAr, lacking hydrogen(s) at the α‐position to nitrogen. They undergo three types of bond‐cleavage, yielding a variety of fragmentation products. 3. a) Anodic oxidation of symmetrical bisamides of type ZCONH(CH2)nNHCOZ (Z=Me, Ph, Ar; n=2–4) under constant current electrolysis, in methanol. For n=3, 4 they afford mostly mono‐ and dimethoxylation products. For n=2 they undergo ′CH2−CH2′ bond cleavage to yield fragmentation products. b) Anodic oxidation of symmetrical bisamides of type ArCONH(CH2)2NHCOAr under controlled potential electrolysis, in acetonitrile, leads to gem‐unsymmetrical bisamides of type ArCONHCH2NHCOMe as the major product, in fair yields. 4. Utilization of the anodic process in organic synthesis to form C−C bonds by both intra‐ and inetrmolecular processes; as well as C−O and C−N bonds for generating heterocycles. [ABSTRACT FROM AUTHOR]

The lipophilicity of a substance is an important physicochemical parameter for the pharmacological activity of a drug. In the current study, high-performance thin-layer chromatography was applied to determine the LogP values of the following anticoagulant drugs: warfarin, acenocoumarol, clopidogrel, and prasugrel. The mobile phase was a mixture of acetonitrile and water in mixed proportions. The content of acetonitrile varied from 50% to 80% in 5% increments. The partition coefficients were calculated with the regression curve Rm0 = f(LogP) based on the compounds with known lipophilicity. The highest LogP was observed for warfarin and the lowest for prasugrel. [ABSTRACT FROM AUTHOR]

The creation of supercapacitors with superior energy density and power capabilities is critical for advanced energy storage solutions. Ionic liquid electrolytes offer a promising alternative in this respect. However, improving their cycle stability and efficiency is a complex task requiring extensive research and significant effort. The high viscosity of ionic liquids (ILs) limits their lifetime, but this can be mitigated by increasing the temperature or adding solvents. In this research, the electrochemical performance of symmetric activated carbon supercapacitors with 1-Ethyl-3-methylimidazolium tetrafluoroborate (EMIMBF4) and different ratios of acetonitrile (ACN) as electrolytes were investigated. Long-term galvanostatic charge/discharge tests, impedance studies, and cyclic voltammetry were performed at temperatures between 24 to 60 °C. The addition of ACN to the ionic liquid increased electrochemical stability and reduced internal resistance, with the best performance observed at a 1:2 volume ratio of EMIMBF4 to ACN. This supercapacitor exhibited 87% cyclic stability after 5000 charge/discharge cycles in the voltage range of 0.05–2.8 V and a current rate of 1 Ag−1. It also achieved an energy density of 23 Whkg−1 and a power density of 748 Wkg−1. The supercapacitors were stable at elevated temperatures up to 60 °C, showing no degradation after operation under various thermal conditions. [ABSTRACT FROM AUTHOR]

The increasing use of chemicals requires a better understanding of their presence and dynamics in the environment, as well as their impact on ecosystems. The aim of this study was to validate the first steps of an innovative multi-omics approach based on metabolomics and 16S metabarcoding data for analyses of the fate and impact of contaminants in Mediterranean lagoons. Semi-targeted analytical procedures for water and sediment matrices were implemented to assess chemical contamination of the lagoon: forty-six compounds were detected, 28 of which could be quantified in water (between 0.09 and 47.4 ng/L) and sediment (between 0.008 and 26.3 ng/g) samples using the UHPLC-MS/MS instrument. In addition, a non-targeted approach (UHPLC-HRMS) using four different sample preparation protocols based on solid/liquid extractions or an automated pressurized fluid extraction system (EDGE®) was carried out to determine the protocol with the best metabolome coverage, efficiency and reproducibility. Solid/liquid extraction using the solvent mixture acetonitrile/methanol (50/50) was evaluated as the best protocol. Microbial diversity in lagoon sediment was also measured after DNA extraction using five commercial extraction kits. Our study showed that the DNeasy PowerSoil Pro Qiagen kit (Promega, USA) was the most suitable for assessing microbial diversity in fresh sediment. [ABSTRACT FROM AUTHOR]

AbstractThe combination of an anticoagulant and a hypolipidemic agent is commonly used in patients at risk for stroke because it controls thrombosis and lowers cholesterol levels. However, the use of anticoagulants carries a high risk of life-threatening bleeding. To address the need for personalized clinical monitoring and risk management, we developed a rapid and sensitive HPLC method with a streamlined sample preparation process. This method enables the simultaneous determination of concentrations for two commonly used anticoagulant drugs (apixaban and rivaroxaban) and three hypolipidemic drugs (rosuvastatin, atorvastatin calcium, and simvastatin). The chromatographic conditions and sample preparation methods were optimized. The drugs were well separated by the gradient elution of phosphoric acid (0.01%, v/v) and acetonitrile at a flow rate of 1.0 mL/min within 40 min on an Athena C18-WP column (4.6 × 150 mm, 5-μm particle size). The proposed method was linear (r2 ≥ 0.994) within the concentration ranges of 0.22–20 μg·mL−1 for the five analytes, including the expected range of therapeutic concentrations. This method enables simultaneous monitoring of the levels of the mentioned drugs in clinical practice. Furthermore, the chromatographic conditions were simple and feasible, making them highly suitable for emergency clinical medication monitoring in basic medical institutions. [ABSTRACT FROM AUTHOR]

An electrochemical decarboxylative addition of N‐substituted glycines to enaminones has been developed and conducted under oxidant‐, catalyst‐, and light‐free conditions in acetonitrile at room temperature by using electron as the traceless oxidant, which provided a green approach to access C3‐aminomethyl chromones. The resulting products were formed through radical addition/oxidation/cyclization or electrophilic addition/cyclization pathway and could act as valuable building blocks to construct polysubstituted pyrimidine derivatives. [ABSTRACT FROM AUTHOR]

Herein, a novel electrochemical sensor that was used for the first time for sensitive and selective detection of dopamine (DA) was fabricated. The new sensor is based on the decoration of the glassy carbon electrode surface (GC) with a polymer film of 1,3-Benzothiazol-2-yl((4-carboxlicphenyl)hydrazono)) acetonitrile (poly(BTCA). The prepared (poly(BTCA) was examined by using different techniques such as 1H NMR, 13C NMR, FTIR, and UV-visible spectroscopy. The electrochemical investigations of DA were assessed using cyclic voltammetry (CV) and differential pulse voltammetry (DPV). The results obtained showed that the modifier increased the electrocatalytic efficiency with a noticeable increase in the oxidation peak current of DA in 0.1 M phosphate buffer solution (PBS) at an optimum pH of 7.0 and scan rate of 200 mV/s when compared to unmodified GC. The new sensor displays a good performance for detecting DA with a limit of detection (LOD 3σ), and limit of quantification (LOQ 10σ) are 0.28 nM and 94 nM respectively. The peak current of DA is linearly proportional to the concentration in the range from 0.1 to 10.0 µM. Additionally, the fabricated electrode showed sufficient reproducibility, stability, and selectivity for DA detection in the presence of different interferents. The proposed poly(BTCA)/GCE sensor was effectively applied to detect DA in the biological samples. [ABSTRACT FROM AUTHOR]

AbstractThis study focused on the biodegradation of acetonitrile (ACN) and subsequent nitrification using a mesophilic microbial consortium isolated from Phragmites australis and Zantedeschia aethiopica plants which were in a nitrile-contaminated habitat. The organisms were identified using 16S rDNA sequencing and were determined to be Bacillus sp., Pseudomonas sp., and Enterobacter sp. organisms. These organisms were used as a consortium in the biodegradation of ACN. The physicochemical conditions including temperature, pH, and ACN concentration were optimized using response surface methodology (RSM). Based on this method, an optimal biodegradation efficiency of 99% was achieved at an optimized temperature of 34.99 °C, pH of 7:03, and an ACN concentration of up to 127.23 mg/L. These optimized parameters were used in the continuous operation over a period of 122 days with increased ACN concentrations of 150–500 mg/L where the biodegradation efficiency exceeded 99% which were accompanied by the production of acetic acid, acetamide, and nitrogenous compounds. Acetic acid and acetamide were completely utilized while total nitrogen (TN) was 1.2 mg/L on the last day of the study. [ABSTRACT FROM AUTHOR]

Recently, hexahydrocannabinol (HHC) was posed under strict control in Europe due to the increasing HHC-containing material seizures. The lack of analytical methods in clinical laboratories to detect HHC and its metabolites in biological matrices may result in related intoxication underreporting. We developed and validated a comprehensive GC-MS/MS method to quantify 9(R)-HHC, 9(S)-HHC, 9αOH-HHC, 9βOH-HHC, 8(R)OH-9(R)-HHC, 8(S)OH-9(S)HHC, 11OH-9(R)HHC, 11OH-9(S)HHC, 11nor-carboxy-9(R)-HHC, and 11nor-carboxy-9(S)-HHC in whole blood, urine, and oral fluid. A novel QuEChERS extraction protocol was optimized selecting the best extraction conditions suitable for all the three matrices. Urine and blood were incubated with β-glucuronidase at 60 °C for 2 h. QuEChERS extraction was developed assessing different ratios of Na2SO4:NaCl (4:1, 2:1, 1:1, w/w) to be added to 200 µL of any matrix added with acetonitrile. The chromatographic separation was achieved on a 7890B GC with an HP-5ms column, (30 m, 0.25 mm × 0.25 µm) in 12.50 min. The analytes were detected with a triple-quadrupole mass spectrometer in the MRM mode. The method was fully validated following OSAC guidelines. The method showed good validation parameters in all the matrices. The method was applied to ten real samples of whole blood (n = 4), urine (n = 3), and oral fluid (n = 3). 9(R)-HHC was the prevalent epimer in all the samples (9(R)/9(S) = 2.26). As reported, hydroxylated metabolites are proposed as urinary biomarkers, while carboxylated metabolites are hematic biomarkers. Furthermore, 8(R)OH-9(R)HHC was confirmed as the most abundant metabolite in all urine samples. [ABSTRACT FROM AUTHOR]

Frequency-domain terahertz (THz) spectroscopy using photomixing devices has unique advantages such as high dynamic range and high spectral resolution. Thus, many applications for solid-state and gas-phase spectroscopy have been proposed. In this study, we developed a feedback controlled technique to dynamically compensate for the optical phase accompanied by frequency sweep, enabling both fast and high-resolution data acquisition across a wide frequency region. From gas-phase THz spectroscopy measurements of dilute acetonitrile gas in a wide frequency range up to 1.1 THz, fine structures with linewidths less than 10 MHz were clearly resolved, while the data acquisition rate was improved by two orders compared to the previously reported value. [ABSTRACT FROM AUTHOR]

This research investigates the synthesis and photocatalytic performance of MM-MOFs based on porphyrin ligands for the conversion of 1,5-DHN to Juglone. This conversion is significant as Juglone serves as a crucial building block in anthraquinone synthesis. MM-MOFs have shown enhanced properties than their monometallic counterparts. In this research, the substitution of the second metal ions in the inorganic nodes will allow the bimetallic system to show synergistic effects and increase the photocatalytic activity. MM-MOFs, in which multifunctional organic linkers (such as porphyrins) are utilized, exhibit superior performance compared to single-functional linkers. Photocatalytic reactions were conducted using varying molar ratios of cobalt and nickel as nodes, and H2TCPP and Mn-TCPP as linkers. The highest photocatalytic efficiency of 69% was achieved using a molar ratio of 1:1 of Co:Ni and Mn-TCPP (Ni50%/Co50% TCPP-Mn), thereby showcasing a synergistic effect between Co:Ni as nodes and Mn-porphyrin as the linker. The synthesized MM-MOFs were extensively characterized using techniques such as FTIR, SEM, BET, XRD, DRS, EDX, XPS and TEM. Additionally, various factors influencing photocatalytic activity, including solvent, oxidant, time and light source were optimized. The best results confirm that acetonitrile as the solvent, 8 mg of MOF, oxygen as the oxidant, a reaction time of 4 h and a Xenon lamp as the light source. The outcomes of this study demonstrate the innovative potential of MM-MOFs as efficient photocatalysts for converting 1,5-DHN to Juglone, with broader implications for applications in catalysis. [ABSTRACT FROM AUTHOR]

Metastable zone width (MSZW) and induction time data for isonicotinamide (INA) in various solvents, including methanol, acetone, acetonitrile, and ethyl acetate, were experimentally measured using a turbidity probe. For the MSZW data, the interfacial energy and pre-exponential factor were determined and compared based on classical nucleation theory (CNT) using the integral model, the linearized integral model, and the classical 3D nucleation theory approach, respectively. For the induction time data, the interfacial energy and pre-exponential factor were determined based on CNT using the conventional method. The nucleation criteria at the nucleation point in derivation of various models were examined in detail. The obtained interfacial energy and pre-exponential factor from the MSZW data for INA in each solvent were compared with those from the induction time data. [ABSTRACT FROM AUTHOR]

Reaction of a sterically demanding iminophosphorano-phosphine, Ph2PCH2Ph2P＝NAr* (here onwards referred to as PCPNAr*; Ar* = 2,6-dibenzhydryl-4-methylphenyl), (1) with [Ru(η6-p-cymene)Cl2]2 yielded three different types of complex, [RuCl2{(η6-p-cymene)(PCPNAr*)-κ1-P}] (2), [RuCl{(P(O)CPNAr*)(κ2-N,C)(C-η6-arene)}] (3) and [RuCl{(POCP＝NAr*)(κ2-N,C-o)(C-η6-arene)}] (4), depending on the reaction conditions via CH activation, tethered η6-arene coordination, ortho-metallation or P＝N bond cleavage/rearrangement reactions. Interestingly, a similar reaction in CH3CN in the presence of AgBF4 resulted in the insertion of CH3CN into the P＝N bond to form a novel metallacycle [Ru(NCMe)3{(PC2P＝N(CH3)C＝NAr*)-κ3-N,N,P}][BF4]2 (5) containing 4- and 5-membered rings via an aza-Wittig type reaction. Complex 4 showed very good catalytic activity in the transfer hydrogenation of carbonyl compounds. [ABSTRACT FROM AUTHOR]

Ondansetron (OND), a serotonin type-3 receptor antagonist exhibits antiemetic activity by blocking both centrally as well as peripherally. It is one of the most common empiric options for the treatment of nausea and vomiting of different etiologies such as chemotherapy-induced nausea vomiting (CINV), radiation-induced NV, postoperative NV as well as off-labeled drugs used in pregnancy. For the quantitative determination of ondansetron in bulk and pharmaceutical dosage form, a simple reversed-phase HPLC method was successfully developed and validated. Nucleodur 100 – 10 C18 column (216 mm, 4.6 mm, and 5 μm) was used. The solvent system was methanol: water: acetonitrile (80:15:5, v/v/v), whose pH was adjusted to 2.8 by using a few drops of ortho-phosphoric acid, delivered at a flow rate of 1ml/min. Eluents were detected at a wavelength of 308 nm. The proposed method was found to be specific, sensitive and linear (R2 > 0.9999) within a desired range of 0.15 – 5 μg/ml, accurate (99.61 – 100.23%), precise (0.004 – 0.2%), and showed good robustness and ruggedness. The limit of detection and quantification was 0.27 μg/ml and 0.8 μg/ml, respectively. A statistically paired sample t-test for the analysis of precision was employed. The proposed method was applied to different marketed formulations. [ABSTRACT FROM AUTHOR]

Iodination of 2-(4-arylthiazole-2-yl)acetonitriles in DMF proceeds with the formation of previously undescribed 2,3-bis(4-aryl-1,3-thiazole-2-yl)but-2-enedicarbonitriles as a mixture of E- and Z-isomers. The latter were alternatively prepared by the reaction of cyanothioacetamide, α-bromoketones and iodine in DMF. Structure of the key compounds was proven by means of single crystal X-ray diffraction analysis. [ABSTRACT FROM AUTHOR]

Rate and product data are reported for the solvolysis reactions of 27 mono, di [3,4] and tri [3,4,5] ring‐substituted benzyl chlorides. The first order rate constant for solvolysis in 20% acetonitrile in water decrease from ksolv = 2.2 s−1 for 4‐methoxybenzyl chloride to 1.1 × 10−8 s−1 for 3,4‐dinitrobenzyl chloride. The product rate constant ratios kMeOH/kTFE for solvolysis in 70/27/3 (v/v/v) HOH/TFE/MeOH range from a minimum of kMeOH/kTFE = 8 to a maximum of 110. The rate data were fit to a four‐parameter Hammett equation that separates the resonance (ρrσr) and polar (ρnσn) effects of the aromatic ring substituents on the reaction rate. Increases in the values of the Hammett reaction constants ρr and ρn are observed as the substituent constants σr or σn are increased. A sharp decrease in the product selectivity kMeOH/kTFE = 26 for stepwise solvolysis of 4‐methoxybenzyl chloride is observed as electron‐withdrawing meta‐substituents are added to 4‐methoxybenzyl ring due to a Hammond‐effect on the position of the transition state for solvent addition to the substituted 4‐methoxybenzyl carbocation reaction intermediates. Sharp increases in the selectivity kMeOH/kTFE are observed with decreasing reactivity of other 3,4,5‐subsituted benzyl chlorides due to anti‐Hammond shifts, on a two‐dimensional More–O'Ferrall reaction coordinate diagram, in the position of the transition state for a concerted solvolysis reaction. [ABSTRACT FROM AUTHOR]

Central composite design based RP-HPLC method optimization for the synchronized analysis of Efonidipine Hydrochloride Ethanolate (EFE) and Chlorthalidone (CHL) in tablet. The effective separation was performed using Inertsil ODS C18 column (250 × 4.6 mm, 5 μm), PDA detector with 0.05 M KH2PO4 Buffer (pH 4.5): Acetonitrile (40:60%v/v) mobile phase. Independent variables were investigated include the concentration of KH2PO4 (X1) and flow rate of mobile phase (X2). Based on responses obtained (retention time, resolution and tailing factor), the optimum condition selected was X1 = 40% and X2 = 1 ml/min. Optimized HPLC condition was validated by assessing validation parameters and it meets the acceptance criteria set by ICH. The linear calibration curve was found to be in the quantity range 6.25–18.75 and 20–60 μg/ml Assay of drugs was 100.94 and 100.06% for CHL and EFE. The validated RP-HPLC-PDA method can be used for routine analysis of EFE and CHL in tablet. [ABSTRACT FROM AUTHOR]

Ivosidenib is used for the treatment of acute myeloid leukemia (AML) with isocitrate dehydrogenase 1 (IDH1) mutations. However, increased blood concentrations of ivosidenib are associated with a risk of a prolonged QT interval in patients with AML. Therapeutic drug monitoring in patients with AML with IDH1 mutation offers the potential to improve treatment efficacy while minimizing toxicity. In this study, we developed an efficient high-performance liquid chromatography–ultraviolet (HPLC-UV) method for the quantification of ivosidenib in plasma. Human plasma samples (50 μL) were processed by protein precipitation using acetonitrile, followed by chromatographic separation on a reversed-phase column with an isocratic mobile phase of 0.5% KH₂PO₄ (pH 4.5) and acetonitrile (45:55, v/v) at a flow rate of 1.0 mL/min, with ultraviolet detection at 245 nm. Calibration curves were linear over the range of 0.25–20 μg/mL with a coefficient of determination (r 2) of 0.99999. Intra-day and inter-day precision were 1.20–8.04% and 0.69–4.20%, respectively. The assay accuracy was −2.00% to 1.93% and recovery was >91.2%. These findings support the effectiveness of the newly developed HPLC-UV method for the quantification of ivosidenib in human plasma. This simple and cost-effective method is expected to expand ivosidenib monitoring in laboratories lacking LC–MS/MS instruments. [ABSTRACT FROM AUTHOR]