查看更多>>摘要：Sauromatum guttatum has been traditionally used in the treatment of snakebite and tumors in India, Pakistan, and China. However, it lacks detailed phytochemical composition like other members of the family Araceae. Therefore, the aim of the present study was to investigate the phytochemical composition of crude methanolic extract and subsequent fractions from S. guttatum tubers and to determine their enzyme inhibitory potentials. The phytochemical profile was studied through tandem high-resolution mass-based phytochemical analysis and Global Natural Product Social (GNPS) molecular networking. Similarly, crude extract and fractions were also investigated for enzyme inhibitory activity against urease and alpha-glucosidase. Twenty-six compounds were dereplicated belonging to flavone C-glycosides, flavone 0-glycosides, phenolic acids, phenolic acid glycosides, and iridoid glycosides. The n-butanol fraction was particularly found rich in flavone di-C-glycosides including schaftoside, isoschaftoside, neoschaftoside, and vicenin-2. The n-butanol fraction exhibited the highest in vitro inhibition against urease and alpha-glucosidase with IC50 values of 113.7 mu g/mL and 155.3 mu g/mL, respectively. The results of enzyme inhibition potential were also supported by in silico molecular docking studies against the above-mentioned enzymes. This is the first report on the detailed phytochemical profile of S. guttatum tubers, and these results will contribute to the chemosystematic knowledge of the Araceae family. The results of this study also suggest that S. guttatum may find possible applications in the treatment of gastrointestinal disorders and diabetes. (C) 2022 Elsevier B.V. All rights reserved.
查看更多>>摘要：Previously introduced structural quality factor (q(max)) of LC column is a measure of its potential kinetic performance - the larger is q(max) the proportionally larger is peak capacity (n(c)) of isothermal and gradient analysis with the same analysis time (t(anal)) and pressure (delta p). However, the best practically achievable column performance depends not only on q(max), but is limited by the narrowest practically achievable widths of the flow-through channels in the column internal support structure. These widths can be represented by the smallest practically achievable column permeability (K-min). Large K-min might result in unnecessarily high n(c) in prohibitively long t(anal). Structure-independent methodology of evaluation of these effects on a column performance limits and relevant equations are developed. The best performance (the shortest t(anal) at a given n(c)) is achieved when a column operates at its highest acceptable delta p (delta p(max)) even if (for reducing t(anal)) the column has to operate under non-optimal conditions. To demonstrate the methodology, three column types with substantially different q(max) the solid-core particle columns (SCPCs), q(max) = 0 . 4 ; the pillar-array columns (PACs), q(max) = 0 . 65 , inter-pillar distance 1.25 mu m; and the porous-layer open-tubular columns (PLOTCs), q(max) = 0 . 97 , 4.6 mu m ID were compared. It is shown that, because practically available K-min of SCPCs is much smaller than that in evaluated PLOTCs or PACs, the latter two cannot outperform contemporary SCPCs with d(p) <= 4 mu m in applications with practically acceptable t(anal), although SCPCs have the lowest q(max). Factors affecting K-min, and the effect of delta p(max) on a column performance limit were also evaluated and discussed. (C)& nbsp;2022 Elsevier B.V. All rights reserved.
查看更多>>摘要：Benzoyl urea insecticides are a class of pesticides used in agriculture for the inhibition of chitin synthesis in pests. These compounds are persistent in environmental samples, and thus their monitoring is necessary to avoid detrimental effects to human health and the environment. Magnet integrated fabric phase sorptive extraction (MI-FPSE) is a recently introduced sample preparation technique that combines sample stirring and analyte extraction into one stand-alone device. However, the applicability and the potential benefits of this technique in environmental analysis remain unexplored. In the present study, MIFPSE was employed for the first time for the extraction and preconcentration of benzoyl urea insecticides (i.e., diflubenzuron, triflumuron, hexaflumuron, lufenuron and chlorfluazuron) from environmental water samples prior to their determination by high performance liquid chromatography-diode array detection (HPLC-DAD). The main factors affecting the performance of the proposed methodology were thoroughly investigated and optimized and the MI-FPSE-HPLC-DAD method was validated. The proposed method enabled the handling of relatively high sample quantity resulting in high preconcentration factors (501 and 731) and good sensitivity. Under optimum conditions, the limits of detection and the limits of quantification for the benzoyl urea insecticides were 0.06 ng mL(-1) and 0.20 ng mL(-1), respectively. Moreover, the relative standard deviations were less than 6.1% for intra-day study and less than 8.2% for inter-day study showing good method precision. After its validation, the herein developed method was successfully employed for the analysis of tap, mineral, river, and lake water samples. In addition, the ComplexGAPI index was used to present the green potential of developed method from the step of MI-FPSE device preparation to final determination. All things considered, MI-FPSE could potentially serve as an efficient tool for the monitoring of pollutants in environmental analysis. (C) 2022 Elsevier B.V. All rights reserved.
查看更多>>摘要：Although commercially available software provides options for automatic peak detection, visual inspec-tion and manual corrections are often needed. Peak detection algorithms commonly employed require carefully written rules and thresholds to increase true positive rates and decrease false positive rates. In this study, a deep learning model, specifically, a convolutional neural network (CNN), was implemented to perform automatic peak detection in reversed-phase liquid chromatography (RPLC). The model inputs a whole chromatogram and outputs predicted locations, probabilities, and areas of the peaks. The obtained results on a simulated validation set demonstrated that the model performed well (ROC-AUC of 0.996), and comparably or better than a derivative-based approach using the Savitzky-Golay algorithm for detect-ing peaks on experimental chromatograms (8.6% increase in true positives). In addition, predicted peak probabilities (typically between 0.5 and 1.0 for true positives) gave an indication of how confident the CNN model was in the peaks detected. The CNN model was trained entirely on simulated chromatograms (a training set of 1,0 0 0,0 0 0 chromatograms), and thus no effort had to be put into collecting and labeling chromatograms. A potential major drawback of this approach, namely training a CNN model on simulated chromatograms, is the risk of not capturing the actual "chromatogram space" well enough that is needed to perform accurate peak detection in real chromatograms.(c) 2022 Elsevier B.V. All rights reserved.
查看更多>>摘要：In the current study, a novel kind of mixed-mode hydrophobic/hydrophilic hybrid silica material has been developed for the solid-phase extraction of hydrophobic and hydrophilic illegal additives from food samples. A hydrophobic hybrid silica material was first prepared by the sol-gel method with tetraethoxysilane, 3-aminopropyltriethoxysilane, and dimethyloctadecyl-[3-(trimethoxysilyl)propyl] ammonium chloride (DTSACl) as precursors. Subsequently, the hydrophobic hybrid silica material was activated by glutaraldehyde, followed by the covalent immobilization of polyethyleneimine (PEI). PEI and the octadecyl group of DTSACl produced the hydrophilic/hydrophobic features of the hybrid silica material. The developed material was characterized by scanning electron microscopy, X-ray photoelectron spectroscopy, Fourier transform infrared spectroscopy, solid-state nuclear magnetic resonance, zeta potential analyzer, and laser diffraction particle size analyzer, then applied as a hydrophobic and hydrophilic sorbent for the solid-phase extraction (SPE) of benzodiazepines from ginseng amino acid oral liquid as well as melamine and cyromazine from powdered milk, followed by RPLC/HILIC-MS/MS analysis. The composition and volumes for SPE loading and elution solutions were optimized in detail. Coupled with RPLC/HILIC-MS/MS, the proposed method provided satisfactory linearity in the range from 0.9-3.2 mu g kg(-1) to 100-250 mu g kg( -1) with the coefficients of determination higher than 0.99. The limits of detection ranged from 0.3 to 1.0 mu g kg(-1), and the recoveries ranged from 81.1% to 109.0% with the relative standard deviations less than 8.5% ( n = 3). This report offers a new mixed-mode hydrophobic/hydrophilic hybrid silica material to extract trace hydrophobic and hydrophilic additives from complex samples. (C)& nbsp;2022 Published by Elsevier B.V.
查看更多>>摘要：Online monitoring of quality attributes (QAs) directly within the bioreactor can provide the basis for advanced modes of protein production including process intensification, smart manufacturing, and real-time release testing. The development of technologies to enable monitoring of QAs has been highly challenging due to the relative immaturity of commercial technologies for online analysis, generally low abundance of the attributes requiring highly specialized analytics not always amenable to automation, and the significant burden on development organizations to demonstrate the comparability and suitability of the online technologies resulting in low investment interest. In this study, we present for the first time a fully automated and highly flexible method for direct monitoring of QAs from the bioreactor. The method combines an automated sampling system and multi-dimensional (mD) LC-MS/MS technology to provide a means of quantifying post-translational modifications (PTMs) during the cell culture process and making real-time process decisions based on the resulting peptide mapping data. In doing so, a wide variety of PTMs can be identified and quantified including, but not limited to, oxidation, succinimidation, deamidation, isomerization, and glycosylation. The potential of this analytical workflow for the monitoring and trending of multiple attributes during cell culture production processes was first demonstrated with a standard IgG1 antibody over the production process. Then, the online workflow was applied to a complex format Fc-fusion protein to monitor sialylation. The ability to monitor sialylation offers a unique opportunity to develop process control schemes to ensure the final product meets quality specifications, showing the potential of this workflow in the context of online process analytical technology (PAT). Published by Elsevier B.V.
Abdulhussain, Noorvan Beurden, Anouk S. A.Dekker, Mabel E.Hulsbergen, Annemieke...
9页
查看更多>>摘要：Smokeless powders (SPs) are one of the most commonly used propellants for ammunition but can also be abused as energetic material in improvised explosive devices (IEDs) such as pipe bombs. After a shooting or explosion, unburnt or partially burnt particulates may be observed which can be used for forensic investigation. SPs comprise mainly nitrocellulose (NC) and additives. Therefore, the characterization of both NC and the additives is of significant forensic importance. Typically, the identification, classification, and chemical profiling of smokeless powders are based exclusively on the analysis of the additives. In this study, information regarding the NC base component was combined with the chemical analysis of the additives using two-dimensional liquid chromatography (2D-LC). The system combines size-exclusion chromatography (SEC) and reversed-phase liquid chromatography (RPLC) in an on-line heart-cut 2D-LC configuration. In the first dimension, the NC is characterized by its molecular-weight distribution (MWD) while being separated from the additives. The additives are then transferred to the second-dimension separation using a novel analyte-transfer system. In the second dimension, the additives are separated to obtain a detailed profile of the low-molecular-mass compounds in the SP. With this approach, the MWD of the NC and the composition of the additives in SP have been obtained within an hour. A discrimination power of 90.53% was obtained when studying exclusively the NC MWD, and 99.47% for the additive profile. This novel combination enables detailed forensic comparison of intact SPs. Additionally, no extensive sample preparation is required, making the developed method less labor intensive. (C) 2022 The Author(s). Published by Elsevier B.V.
Lioupi, ArtemisVirgiliou, ChristinaWalter, Thomas H.Smith, Kerri M....
13页
查看更多>>摘要：Metabolic phenotyping studies using mouse liver extracts as a model, performed on a novel zwitterionic HILIC UHPLC column, which is based on ethylene-bridged hybrid organic/inorganic particles bonded with sulfobetaine groups and packed into column hardware modified with hybrid surface technology are reported. Initially the chromatographic performance was evaluated under different mobile phase conditions using selected metabolite standards. Following optimization of the chromatographic conditions for 88 hydrophilic metabolites both targeted and untargeted profiling analyses were performed on tissue extracts using LC-MS/MS and LC-TOF/MS, respectively. Chromatographic efficiency parameters such as peak resolution, peak shapes, selectivity and precision in retention and peak areas as well as characteristics that are critical for metabolic profiling analysis such as metabolite coverage and retention time distribution were assessed. The hybrid zwitterionic column exhibited efficient chromatographic separations providing analysis of ca 80 hydrophilic metabolites from different chemical classes and polarities. Utilizing a one-dimensional separation both targeted and untargeted profiling provided comprehensive metabolic signatures that enabled the acquisition of the metabolic phenotypes of the tissue extracts. (c) 2022 The Authors. Published by Elsevier B.V. This is an open access article under the CC BY-NC-ND license ( http://creativecommons.org/licenses/by-nc-nd/4.0/ )
Bajtai, AttilaNemeti, GaborLe, Tam MinhSzakonyi, Zsolt...
11页
查看更多>>摘要：New amino, thio, and oxy derivatives of monoterpene lactones, amides, and esters have been synthesized and their enantioselective separations were investigated on seven covalently immobilized polysaccharide-based chiral stationary phases. The effects of basic additives, different short-chain alcohols, and the influence of the temperature on the chromatographic behavior were studied. In addition, relationships be-tween the structure of selector and selectand and the chromatographic parameters were explored to reveal mechanistic details of chiral recognition. Experiments were performed in the temperature range 10-50 ? and thermodynamic parameters were calculated from plots of ln alpha versus 1/T. The separations were generally enthalpy-controlled, but entropy-driven separation was also observed. Special attention has been paid to the enantiomer elution order and several examples are shown how the structural char-acteristics of the selector, the nature, and the concentration of the polar modifier induce reversal of the enantiomer elution order in the case of the polysaccharide-based selectors. (C)& nbsp;2022 The Author(s). Published by Elsevier B.V.& nbsp;
Tai, Hua-ChiaLin, ZiqingFabiano, AbigailZhou, Yiyang...
9页
查看更多>>摘要：Determination of stereoisomers is an integral part of pharmaceutical analysis. Chiral liquid chromatography (LC) method development is typically initiated through screening of chiral stationary phases (CSPs) and mobile phases (MPs) since chiral separation is difficult to predict. We have previously reported a screening strategy using chiral reversed-phase (RP) LC as two primary tiers due to its versatility for enantio-recognition and compatibility with diverse sample matrices. Here we focus on developing a normal-phase (NP) LC screening strategy as a secondary tier for chiral method screening. A database was constructed from 60 NPLC screens performed on up to 18 CSPs and 3 MPs using gradient elution. This was used to investigate the effectiveness of NPLC compared to RPLC screening, as well as the impact of MP composition and the selectivity of different CSPs in NPLC screening. A success hit rate of 90% was observed in NPLC compared to 84% in RPLC screening for Bristol Myers Squibb compounds. Importantly, NPLC screening generated successful hit(s) in 81% of the cases that failed in RPLC, demonstrating the value of NPLC as a complementary screening tier. After optimizing the CSP/MP selection, we proposed a NPLC screening workflow with several user-options according to method requirements and instrument capacity. Among these, the most comprehensive NPLC screening consisted of ten CSPs (AD, AS, AY, AZ, OD, OJ, IC, IE, IG, O1) with three MPs. When combined with RPLC, an overall success rate of 97% was achieved for the diverse set of pharmaceutical compounds. (C) 2022 Elsevier B.V. All rights reserved.
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