Peak Area Values Research Articles

Offline Coupling of Hydrophobic Interaction Chromatography-Capillary Zone Electrophoresis for Monitoring Charge-Based Heterogeneity of Recombinant Monoclonal Antibodies.

A holistic understanding of the charge heterogeneity in monoclonal antibodies (mAbs) is paramount for ensuring acceptable product quality. Hence, biotherapeutic manufacturers are expected to thoroughly characterize their products via advanced analytical techniques. Recently, two-dimensional liquid chromatography (2DLC) methods have gained popularity for resolving complex charged species. Capillary electrophoresis (CE) is regarded as a sensitive and faster tool for charged species estimation in biotherapeutics. In this study, we aim to combine the separation power of chromatographic and electrophoretic tools (liquid chromatography [LC]-CE) so as to achieve maximum resolution of mAb charge variants. Hydrophobic interaction chromatography (HIC) has been used as the preferred LC mode with CE for achieving successful separation of both charge and hydrophobic variants for two of the mAbs (trastuzumab and rituximab). The standalone HIC and capillary zone electrophoresis (CZE) methods separated 4 hydrophobic variants and 7 charge variants for each mAb, whereas the 2DLC method separated 10 and 11 variants for mAbs A and B. On the other hand, the HIC-CZE-UV method resolved 29 variants in mAb A and 23 variants in mAb B. The reproducibility of the HIC-CZE-UV method was demonstrated by % change in values of retention time (RT) and peak area as <5% (mAb A), <3% (mAb B), and <12% (for both mAbs), respectively. Thus, the utility of the proposed LC-CE method for characterization of mAb charge variants has been displayed.

Light-induced fading effects on TL and OSL signals and feasibility of dose re-assessment with PTTL signals in BeO dosimeters

Abstract This study aims to investigate both light-induced fading effects on thermoluminescence (TL) and optically stimulated luminescence (OSL) signals under three different light sources (fluorescent, UV-254 and daylight) and dose reassessment with phototransferred TL (PTTL) signals in Beryllium oxide dosimeters. TL and OSL signals were deconvoluted for each light source. Accordingly, variations in the maximum peak temperature, activation energy, peak area value for the TL signal, and intensity and lifetime values for the OSL signal were monitored. Each peak, OSL component, and total area value exhibited different behaviors depending on the light source. Considering the total area condition, the TL intensity decreased by ∼90%, ∼80%, and ∼70% in UV-254, daylight, and fluorescent light exposure, respectively, at the end of the 120 min. On the other hand, the OSL total area intensity faded quickly for both UV-254 and daylight, while it decreased by ∼45% for fluorescent light. According to these results, regardless of TL and OSL measurements, the dosimeters should be kept primarily away from daylight and fluorescent light after irradiation, instead of UV-254, which is rarely encountered in daily life. The feasibility of dose reassessment using PTTL signals under UV-254 light was investigated within a wide dose range from 0.1 to 128 Gy. It is feasible to reassess doses between 0.5 and 32 Gy considering the total area intensity of PTTL signals. In conclusion, PTTL signals can be easily used in fields of the order of Gy, such as in reevaluating doses in radiotherapy applications.

HPTLC Phytochemical Profiling and Simultaneous Quantification of Quercetin and Gallic in Prosopis juliflora (Sw.)

Prosopis juliflora (Sw.) commonly known as jangli babool or vilayati babool have several bioactive compounds of therapeutic needs. The presence of various bioactive compounds and markers specifically, quercetin and gallic acid in the methanolic extract of Prosopis juliflora (fruiting aerial part) denotes their valuable pharmacological activities. Therefore, high performance thin layer chromatography (HPTLC) analysis with simultaneous quantification of quercetin and gallic acid was done for their phytochemical profiling.The phytochemical profiling and simultaneous quantification of quercetin and gallic acid of methanolic extract of Prosopis juliflora through CAMAG HPTLC analysis was determined and results were obtained in the form of chromatogram scanned at the wavelength 254nm and 366nm. Phytochemical profiling of the plant was presented in the tables showing the number of peaks, peak area, area percentage and Rf values. 14 compounds were present in sample 1 and 9 compounds were present in sample 2 denoted by the number of peaks as represented in chromatograms of test samples. Peak area and height were used to quantify quercetin and gallic acid. Quercetin was found to be 1.364% in sample 1 and 0.27% in Sample 2 while gallic acid was 0.088% in sample 1 only. Importance of this research is to rationalize the therapeutic properties of Prosopis juliflora in the indian traditional medicinal system and phytochemical profiling and simultaneous quantification of quercetin and gallic acid reveals that Prosopis juliflora have several bioactive compounds and this might be accountable for their future application in the field of pharmacognostic and pharmacological drug discovery.

Determination of volatile organic compounds (VOCs) in indoor work environments by solid phase microextraction-gas chromatography-mass spectrometry

Volatile organic compounds (VOCs) are continuously emitted into the atmosphere from natural and anthropogenic sources and rapidly spread from the atmosphere to different environments. A large group of VOCs has been included in the class of air pollutants; therefore, their determination and monitoring using reliable and sensitive analytical methods represents a key aspect of health risk assessment. In this work, an untargeted approach is proposed for the evaluation of the exposure to volatile organic compounds of workers in an engine manufacturing plant by GC–MS measurements, coupled with solid-phase microextraction (SPME). The analytical procedure was optimized in terms of SPME fiber, adsorption time, desorption time, and temperature gradient of the chromatographic run. For the microextraction of VOCs, the SPME fibers were exposed to the air in two different zones of the manufacturing factory, i.e., in the mixing painting chamber and the engine painting area. Moreover, the sampling was carried out with the painting system active and running (system on) and with the painting system switched off (system off). Overall, 212 compounds were identified, but only 17 were always present in both zones (mixing painting chamber and engine painting area), regardless of system conditions (on or off). Finally, a semi-quantitative evaluation was performed considering the peak area value of the potentially most toxic compounds by multivariate data analyses.

Formation of Cysteine Adducts with Chlorogenic Acid in Coffee Beans.

The post-harvest processing of coffee beans leads to a wide range of reactions involving proteins. The formation of crosslinks between proteins and phenolic compounds present in high concentrations of coffee beans represents one of the most challenging and still not fully characterized reactions. The aim of this work was to assess the presence of products from such reactions in coffee samples, focusing on the adducts between cysteine and chlorogenic acids (CQAs). For this purpose, 19 green and 15 roasted coffee samples of the Coffea arabica, Coffea canephora, and Coffea liberica varieties were selected for this study and basically characterized. Then, targeted liquid chromatography mass spectrometry (LC-MS/MS) methods were developed to assess the formation of adducts between CQA and cysteine, glutathione, and N-acetylcysteine as the amino acid and peptide models, and quantified such adducts in coffee samples. The results of the characterization showed a heterogeneous distribution of the protein content (8.7-14.6%), caffeine (0.57-2.62 g/100 g), and antioxidant capacity (2-4.5 g ascorbic acid/100 g) in Arabica, Canephora, and Liberica samples. Glutamic acid, arginine, and proline were found to be the major amino acids, while 5-CQA (38-76%), 3-CQA (4-13%), and 4-CQA (4-13%) were the most abundant CQA derivatives of all coffee varieties. The model experiments for adduct formation demonstrated that cysteine binds to CQA via thiol groups and 5-CQA initially isomerizes to 3- and 4-CQA, depending on the conditions, allowing cysteine to bind to two different sites on 3-, 4- or 5-CQA molecules, thus, forming six different Cys-CQA adducts with m/z 476. The reaction was more favored at pH 9, and the adducts proved to be stable up to 90 °C for 10 min and up to 28 days at room temperature. The relative quantification of adducts showed peak area values ranging from 1100 to 3000 in green coffee bean samples, while no adducts were detected in roasted coffee beans. Overall, this work was the first attempt to demonstrate the presence of Cys-CQA adducts in coffee beans and paves the way for further investigations of such adduct formation at the protein level.

Rapid and sensitive in situ detection of heavy metals in fish using enhanced Raman spectroscopy

Heavy metals have been widely applied in industry, agriculture, and other fields because of their outstanding physics and chemistry properties. They are non-degradable even at low concentrations, causing irreversible harm to the human and other organisms. Therefore, it is of great significance to develop high accuracy and sensitivity as well as stable techniques for their detection. Raman scattering spectroscopy and atomic absorption spectrophotometer (AAS) were used parallelly to detect heavy metal ions such as Hg, Cd, and Pb of different concentrations in fish samples. The concentration of the heavy metals is varied from 5 ppb to 5 ppm. Despite the satisfactory recoveries of AAS, their drawbacks are imperative for an alternative technique. In Raman scattering spectroscopy, the intensities and areas of the characteristic peaks are increased with increasing the concentration of the heavy metals. For Hg concentration ≥ 1 ppm, a slight shift is observed in the peak position. The obtained values of peak intensity and peak area are modeled according to Elvoich, Pseudo-first order, Pseudo-second order, and asymptotic1 exponential model. The best modeling was obtained using the Elovich model followed by the asymptotic1 exponential model. The introduced Raman spectroscopy-based approach for on-site detection of trace heavy metal pollution in fish samples is rapid, low-cost, and simple to implement, increasing its visibility in food safety and industrial applications.

Contents of an Early Byzantine Amphora from Kruglaya Bay, the Black Sea

A fragment of an amphora found in the Kruglaya Bay near Sevastopol was filled with an unknown brown substance with a strong smell of tar. On the vessel’s neck, there is a round stamp ~30 mm in diameter, depicting the bust of an emperor encircled by an inscription. It resembles stamps on amphorae made in Alexandria and the Geronisos Island. The inscription reads, “επί Πτολεμαίου επάρχου”. The gas chromatography–mass spectrometry analysis revealed dehydroabietic acid, methyl dehydroabietate, norabietatrienes, retene, and other phenanthrene derivatives, suggesting that the substance resulted from dry distillation of wood of the Pinaceae family. The headspace analysis yielded components of turpentine oil such as α-pinene, camphene, limonene, cymenes, and others terpenes. To establish the sample’s origin, the amphora’s content was compared with modern pinewood tar obtained by the traditional method. Given nearly identical chromatogram profiles of the amphora’s contents and of tar in areas relating to resin acids, similar values of peak areas of biomarker components, and the presence of turpentine oil components in the sample, it is highly probable that the amphora indeed contained tar.

HPTLC Analysis of Tephorisa pulicherrima (Baker) Gamble Ethanol Extract of Root

Tephrosia pulcherrima commonly known as “Kalakkozhuppa,” is well known for its therapeutic properties in the Indian traditional medicinal system. The presence of important bioactive compounds in plants makes them pharmacologically valuable. Therefore, in this study, the High-Performance Thin Layer Chromatography (HPTLC) analysis of Tephrosia pulcherrima (root) ethanol extract was performed for its phytochemical profiling. The HPTLC densitometric analysis of the ethanol extract of Tephrosia pulcherrima was carried out using CAMAG HPTLC system, and the results were obtained in the form of chromatograms (scanned at the wavelength of 254 nm and 366 nm) representing several peaks. The phytochemical profile of the plant was determined and presented in the tables showing the total number of peaks, peak heights, peak area, percent area, and Rf values. The study concluded that T. pulcherrima ethanol extract of the root contains a rich variety of phytochemicals which might be accountable for its therapeutic value and thus justifies its traditional use in India.

Effects of Pregnancy on Plasma Sphingolipids Using a Metabolomic and Quantitative Analysis Approach.

Changes in the maternal metabolome, and specifically the maternal lipidome, that occur during pregnancy are relatively unknown. The objective of this investigation was to evaluate the effects of pregnancy on sphingolipid levels using metabolomics analysis followed by confirmational, targeted quantitative analysis. We focused on three subclasses of sphingolipids: ceramides, sphingomyelins, and sphingosines. Forty-seven pregnant women aged 18 to 50 years old participated in this study. Blood samples were collected on two study days for metabolomics analysis. The pregnancy samples were collected between 25 and 28 weeks of gestation and the postpartum study day samples were collected ≥3 months postpartum. Each participant served as their own control. These samples were analyzed using a Ultra-performance liquid chromatography/mass spectroscopy/mass spectroscopy (UPLC/MS/MS) assay that yielded semi-quantitative peak area values that were used to compare sphingolipid levels between pregnancy and postpartum. Following this lipidomic analysis, quantitative LC/MS/MS targeted/confirmatory analysis was performed on the same study samples. In the metabolomic analysis, 43 sphingolipid metabolites were identified and their levels were assessed using relative peak area values. These profiled sphingolipids fell into three categories: ceramides, sphingomyelins, and sphingosines. Of the 43 analytes measured, 35 were significantly different during pregnancy (p < 0.05) (including seven ceramides, 26 sphingomyelins, and two sphingosines) and 32 were significantly higher during pregnancy compared to postpartum. Following metabolomics, a separate quantitative analysis was performed and yielded quantified concentration values for 23 different sphingolipids, four of which were also detected in the metabolomics study. Quantitative analysis supported the metabolomics results with 17 of the 23 analytes measured found to be significantly different during pregnancy including 11 ceramides, four sphingomyelins, and two sphingosines. Fourteen of these were significantly higher during pregnancy. Our data suggest an overall increase in plasma sphingolipid concentrations with possible implications in endothelial function, gestational diabetes mellitus (GDM), intrahepatic cholestasis of pregnancy, and fetal development. This study provides evidence for alterations in maternal sphingolipid metabolism during pregnancy.

Quality Control in Targeted GC-MS for Amino Acid-OMICS.

Gas chromatography-mass spectrometry (GC-MS) is suitable for the analysis of non-polar analytes. Free amino acids (AA) are polar, zwitterionic, non-volatile and thermally labile analytes. Chemical derivatization of AA is indispensable for their measurement by GC-MS. Specific conversion of AA to their unlabeled methyl esters (d0Me) using 2 M HCl in methanol (CH3OH) is a suitable derivatization procedure (60 min, 80 °C). Performance of this reaction in 2 M HCl in tetradeutero-methanol (CD3OD) generates deuterated methyl esters (d3Me) of AA, which can be used as internal standards in GC-MS. d0Me-AA and d3Me-AA require subsequent conversion to their pentafluoropropionyl (PFP) derivatives for GC-MS analysis using pentafluoropropionic anhydride (PFPA) in ethyl acetate (30 min, 65 °C). d0Me-AA-PFP and d3Me-AA-PFP derivatives of AA are readily extractable into water-immiscible, GC-compatible organic solvents such as toluene. d0Me-AA-PFP and d3Me-AA-PFP derivatives are stable in toluene extracts for several weeks, thus enabling high throughput quantitative measurement of biological AA by GC-MS using in situ prepared d3Me-AA as internal standards in OMICS format. Here, we describe the development of a novel OMICS-compatible QC system and demonstrate its utility for the quality control of quantitative analysis of 21 free AA and metabolites in human plasma samples by GC-MS as Me-PFP derivatives. The QC system involves cross-standardization of the concentrations of the AA in their aqueous solutions at four concentration levels and a quantitative control of AA at the same four concentration levels in pooled human plasma samples. The retention time (tR)-based isotope effects (IE) and the difference (δ(H/D) of the retention times of the d0Me-AA-PFP derivatives (tR(H)) and the d3Me-AA-PFP derivatives (tR(D)) were determined in study human plasma samples of a nutritional study (n = 353) and in co-processed QC human plasma samples (n = 64). In total, more than 400 plasma samples were measured in eight runs in seven working days performed by a single person. The proposed QC system provides information about the quantitative performance of the GC-MS analysis of AA in human plasma. IE, δ(H/D) and a massive drop of the peak area values of the d3Me-AA-PFP derivatives may be suitable as additional parameters of qualitative analysis in targeted GC-MS amino acid-OMICS.

Screening anti-fatigue components of American ginseng saponin by analyzing spectrum-effect relationship coupled with UPLC-Q-TOF-MS.

American ginseng has an obvious anti-fatigue effect, but the effective material basis is still unclear. The spectrum-effect relationship is a scientific method that studies the correlations between chemical spectra and pharmacological effect. To reveal the real bioactive compounds in American ginseng saponin (AGS) based on a study of the underlying correlations between these compounds' occurrence in rat serum after their intake of AGS and the anti-fatigue effect of AGS. We utilized ultra-performance liquid chromatography (UPLC) with quadrupole and time-of-flight mass spectrometry (Q-TOF-MS) to analyze the extract of AGS and its constituents in serum after oral administration in rats. The anti-fatigue effect of AGS in rats was measured using the time weight-bearing swimming technique, the content of blood urea nitrogen, hepatic glycogen, and blood lactic acid. The relationship between the peak area values in fingerprints from rat serum and pharmacodynamic parameters of AGS was established using correlation analysis with partial least square regression (PLSR) method and gray correlation method. We detected and identified 22 compounds from extract, and 8 prototype components from serum. Through PLSR and gray correlation method, it was found that the ginsenosides Re, Rb1, and Rb2 were significantly positively related to the pharmacodynamic data. Based on the spectrum-effect relationship, PLSR and gray correlation method can be used to screen for the anti-fatigue components available in AGS. Such an approach is of practical significance as it provides an effective means for exploring the material basis for the efficacy of American ginseng, particularly as an anti-fatigue agent.

Autonomous capillary electrophoresis processing and analysis of dried blood spots for high-throughput determination of uric acid

A new set-up for fully autonomous and high-throughput capillary electrophoresis (CE) analyses of dried blood spot (DBS) samples is presented. The DBS samples were prepared by collecting exactly 5 μL of capillary blood from a finger-prick onto a pre-punched DBS disc in a disposable plastic CE vial and by in-vial blood drying. The vials with the DBS samples were then loaded into a commercial CE instrument for a fully unmanned sample processing and analysis. A fused-silica capillary of the CE instrument was first used for the transfer of 100 μL of elution solvent to each vial, in-vial DBS elution, and in-vial eluate homogenization. The same capillary was also used for at-line injection, separation, and selective analysis of the resulting eluates. Novel CE sequences were tailor-programmed for consecutive processing and analyses of multiple DBSs, which facilitated a fully autonomous determination of uric acid with a throughput of 240 DBS samples per day (24 h). The presented analytical protocol (using 100 μm i. d./30 cm capillary; 30 mM 2-(N-morpholino)-ethanesulfonic acid, 30 mM l-histidine, and 30 μM cetyltrimethylammonium bromide background electrolyte solution; and UV detection at 292 nm) provided excellent precision at endogenous and spiked uric acid concentrations with RSD values of peak areas below 3.2%. Calibration curves were linear over the 33.3 − 1200 μM range (R2 better than 0.998), limits of detection and quantification in the original capillary blood were 10 and 33.3 μM, respectively, and were well below the uric acid clinical range (140–420 μM). The stability of uric acid in DBS samples stored at laboratory temperature for up to 2 months was also excellent demonstrating less than a 4.2% decrease in uric acid concentrations. The actual set-up might thus be highly attractive for clinical subjects and laboratories because it is minimally invasive and requires minimum intervention from laboratory staff.

Preparation of open tubular capillary column covalently coated with polystyrene sulfonate with 4,4'-azobis (4-cyanopentanoyl chloride) as polymerization initiator for electrochromatographic separation of alkaloids, sulfonamides and peptides.

An open tubular capillary electrochromatography column covalently bonded with polystyrene sulphonate was prepared via in situ polymerization using functionalized azo-initiator 4,4'-Azobis(4-cyanopentanoyl chloride). Scanning electron, fluorescence and atomic force microscopy techniques showed the formation of a relatively rough layer of polymer. In addition, -CN and C = O stretching vibrations from infrared spectroscopy proved the successful immobilization of the azo-initiator through covalent bonding and X-rayPhotoelectronSpectroscopy confirmed the elemental composition of the formed polymer layer. The prepared column was found to be appropriate for small and medium-sized molecules separation. Compared to bare fused silica capillary column higher selectivity and resolution were obtained for the separation of alkaloids, sulfonamides and peptides as a result of the electrostatic and pi-pi stacking interactions between the small organic molecules and the coated column without compromising the electroosmotic flow mobility. Separation efficiency was also increased compared to the bare capillary for the separation of alkaloids (about 1.5 times). Moreover, intraday, inter day, intra batch and inter batch relative standard deviation values of retention time and peak area of peptides were within 2% and 10%, respectively, indicating a good repeatability of the column preparation procedure. The developed method for the covalent bonding of polymers through a functionalized azo-initiator could represent a promising stable method for the preparation of open tubular column. This article is protected by copyright. All rights reserved.

On-line aptamer affinity solid-phase extraction direct mass spectrometry for the rapid analysis of α-synuclein in blood

On-line aptamer affinity solid-phase extraction direct mass spectrometry (AA-SPE-MS) is presented for the rapid purification, preconcentration, and characterization of α-synuclein (α-syn), which is a protein biomarker related to Parkinson's disease. Valve-free AA-SPE-MS is easily implemented using the typical SPE microcartridges and instrumental set-up necessary for on-line aptamer affinity solid-phase extraction capillary electrophoresis-mass spectrometry (AA-SPE-CE-MS). The essential requirement is substituting the application of the separation voltage by a pressure of 100 mbar for mobilization of the eluted protein through the capillary towards the mass spectrometer. Under optimized conditions with recombinant α-syn, repeatability is good in terms of migration time and peak area (percent relative standard deviation (%RSD) values (n = 3) are 1.3 and 6.6% at 1 μg mL−1, respectively). The method is satisfactorily linear between 0.025 and 5 μg mL−1 (R2 > 0.986), and limit of detection (LOD) is 0.02 μg mL−1 (i.e. 1000, 500, and 10 times lower than by CE-MS, direct MS, and AA-SPE-CE-MS, respectively). The established AA-SPE-MS method is further compared with AA-SPE-CE-MS, including for the analysis of α-syn in blood. The comparison discloses the advantages and disadvantages of AA-SPE-MS for the rapid and sensitive targeted analysis of protein biomarkers in biological fluids.

Inducing aluminum oxide growth at room temperature and atmospheric pressure through low dose gamma-ray irradiation

The corrosion resistance of the aluminum is well-known and it is attributed to passivation, a process that occurs when the metal surface reacts to the environment to form a spontaneously thin oxide film. Basically, the natural aluminum oxide film is composed of two layers, an internal layer composed entirely by Al2O3, and a second one made by Al(OH)3. In normal conditions of temperature and pressure, the Al(OH)3 film takes a long time to grow, something around several weeks or months. However, in the present work, through the use of low doses gamma-ray irradiation in an environment composed by air and water vapor, it was possible, in a few days, to increase the layer of Al(OH)3 on a sample of pure aluminum. Using a Cs-137 disk as a gamma-ray source, three aluminum samples were irradiated during 14, 8 and 5 days, receiving absorbed doses of 2.85 mGy, 1.49 mGy and 0.94 mGy, respectively. Comparing the Raman spectrum of the two irradiated samples with another non-irradiated sample, it was possible to verify that the sample irradiated during 14 days had the greatest values of peak intensity and peak area, indicating a higher concentration of aluminum hydroxide when compared to other samples. Moreover, the polarization curves of samples were obtained to analyze the nature of the film formed on the surface. From the results, it was possible to observe that the gamma-ray irradiation led to an improvement in passive film quality (higher resistance), once the irradiation resulted in a lower passivation current density (ipass). To confirm the consistence of previous analysis, more two samples were examined through X-ray photoelectron spectroscopy (XPS), where a sample irradiated during five days showed an increase in the percentage of aluminum hydroxide (related to XPS O 1s peak) in comparison to a non-irradiated sample. Then, it can be pointed that the irradiation, in a low dose, induced the growth of the aluminum hydroxide layer of passive film and improved the film's resistance in a few days. Moreover, the results show the utility of applying low doses of ionizing irradiation to change metal oxide surfaces.

Agathis robusta Bark Extract Protects from Renal Ischemia-Reperfusion Injury: Phytochemical, In Silico and In Vivo Studies.

Background: Acute kidney injury (AKI) induced by renal ischemia-reperfusion injury (RIRI) is associated with a high incidence of mortality. Existing therapies are mainly supportive, with no available nephroprotective agent. The purpose of this study is to examine the potential protective effect of Agathis robusta Bark Extract (ARBE) in RIRI. Methods: The chemical composition of ARBE was examined by LC-ESI-MS/MS. Network pharmacology was utilized to identify the RIRI molecular targets that could be aimed at by the identified major components of ARBE. Experimentally validated protein–protein interactions (PPIs) and compound-target networks were constructed using the STRING database and Cytoscape software. Molecular docking studies were employed to assess the interaction of the most relevant ARBE compounds with the hub RIRI-related targets. Furthermore, ARBE was tested in a rat model of RIRI. Results: The phytochemical analysis identified 95 components in ARBE, 37 of which were majors. Network analysis identified 312 molecular targets of RIRI that were associated with ARBE major compounds. Of these 312, the top targets in the experimentally validated PPI network were HSP90, EGFR, and P53. The most relevant compounds based on their peak area and network degree value included narcissoside, isorhamnetin-3-O-glucoside, and syringetin-3-O-glucoside, among others. Docking studies of the most relevant compounds revealed significant interactions with the top RIRI-related targets. In the in vivo RIRI experiments, pretreatment of ARBE improved kidney function and structural changes. ARBE reduced the renal expression of p-NfkB and cleaved caspase-3 by downregulating HSP90 and P53 in rats exposed to RIRI. Conclusion: Taken together, this study revealed the chemical composition of ARBE, depicted the interrelationship of the bioactive ingredients of ARBE with the RIRI-related molecular targets, and validated a nephroprotective effect of ARBE in RIRI.

Tractable Method for Rapid Quality Assessment of Therapeutic Antibodies in Harvested Cell Culture Fluid based on FcγRIIIa-Immobilized Magnetic Microspheres.

FcγRIIIa-binding affinity is one of the key factors to ensure the efficacy of many antitumor therapeutic antibodies, which should be monitored along with the titer, protein aggregation, and other critical quality attributes. The conventional workflow for the quality assessment of therapeutic antibodies in harvested cell culture fluid (HCCF) is time-consuming and costly nevertheless. In this study, a tractable method was established for rapid quality assessment of a HCCF sample through differentially extracting IgG with different FcγRIIIa affinity levels using FcγRIIIa-immobilized magnetic microspheres, followed by size exclusion chromatography (SEC) to determine the amount and monomer percentage of IgGs in the preceding eluate. FcγRIIIa-immobilized magnetic microspheres with polydopamine (PDA) and hydrophilic dendrimer (PAMAM) coating (denoted as Fe3O4@PDA@PAMAM-FcγRIIIa) were synthesized for the first time as magnetic adsorbents. The PDA cladding endowed the composites with good chemical stability in acidic elution buffer, and the PAMAM dendrimer empowered the composites of high ligand immobilization capacity and hydrophilic surface. The labile FcγRIIIa was immobilized under mild conditions. By directly applying a simple magnetic solid phase extraction procedure to treat HCCF, favored IgG species with high FcγRIIIa affinity would be selectively captured by Fe3O4@PDA@PAMAM-FcγRIIIa composites for subsequent SEC analysis. The monomer peak area value in SEC, which was set as the read-out of the proposed method, correlated directly with the theoretical overall quality of standard-spiked HCCF samples.

Evaluation of Roundup® effects on Chlorella vulgaris through spectral changes in photosynthetic pigments in fresh and marine water

• Roundup® caused spectral changes in photosynthetic pigments of Chlorella vulgaris . • Absorption spectra and peak areas were used to monitor toxic effects. • Cells were stimulated from 10 to 5,000 µg L −1 in freshwater and inhibited otherwise. • C. vulgaris adapted to seawater was more tolerant above 1 mg L −1 of glyphosate. • The dose-response relationship depended on salinity. Glyphosate is a broad-spectrum herbicide whose use is now restricted because of its potential toxicity to human and environmental health. Its presence is observed even in aquatic ecosystems where this emerging contaminant affects primary producers such as phytoplankton. This study focuses on the cosmopolitan green microalga, Chlorella vulgaris Beijerinck, 1890. The ecotoxicological effects of the commercial herbicide, Roundup®, were evaluated in freshwater (FW) and seawater (SW) using ultraviolet/visible spectroscopy over a five-day experiment. A dose-response relationship was investigated on a wide range of concentrations (0.1 to 25,000 µg L −1 ). The population of FW- Chlorella was stimulated when exposed to concentrations from 10 to 5,000 µg L −1 and inhibited otherwise. Chlorophylls and carotenoids exhibited their highest peak area values after four days, before their signal was depleted by day 5, regardless of Roundup® concentration. Conversely, cells of SW- Chlorella were stimulated at the highest concentrations (> 1 mg L −1 ), as if glyphosate was acting as a source of phosphorous nutrient. The peak areas of chlorophylls and carotenoids increased in the presence of the contaminant, especially on day 3. The defense mechanisms activated during its adaptation to marine salinity ( e.g. , decrease in the chlorophyll/carotenoid peak area ratio) could have favored its resilience. Exposure to Roundup® caused a shift in the wavelength at maximum absorbance, which could introduce a bias when measuring peak heights at a single wavelength. The analysis of absorption spectra and the use of peak areas appear to be a promising approach for monitoring changes in photosynthetic pigments.

Univariate data analysis versus multivariate approach in liquid chromatography. An application for melamine migration from food contact materials

The aim of this work is focused on the melamine migration from food contact materials (FCMs), considering data obtained from univariate analysis versus that obtained from multivariate approach in liquid chromatography coupled to diode array detector.Plastic food contact materials are made from monomers and additives. Moreover, non-intentionally added substances (NIAS) can be part of the composition of the FCM: raw material impurities or process by-products, inks or adhesives.Any compound present within a FCM can migrate to foodstuff. Specific migration of some substances from plastic FCMs to food/simulant is limited by European legislation in force (Commission Regulation No 10/2011).Quantification of analytes in migration samples through a univariate analysis could lead to erroneous results. As an example, in liquid chromatography NIAS can interfere when coeluting with analytes or when they have close retention time. In that case, an overestimation would happen and the verification of the compliance of the specific migration limit (SML) of a substance would be incorrect.A solution to the problem can be found in the application of a chemometric tool with the second-order advantage, which allows the unequivocal identification of analytes. Specifically, for this work, PARAFAC/PARAFAC2 decomposition technique along with tensors arranged from HPLC-DAD data of migration (test and kinetics) samples were used for the identification and quantification of melamine.Results of melamine quantity found in migration samples from five types of melaware by means of a multivariate approach were compared to results obtained with a univariate data analysis carried out with values of chromatographic peak area as response. The comparison reveals that in test samples, univariate analysis supposes an overestimation in the quantity of melamine of 30 % on average, with respect of the concentration obtained from the multivariate approach. Besides, in kinetics samples it is remarkable that for one migration cycle the melamine found was 10 times above the one that obtained with PARAFAC decomposition.Summing up, multivariate data analysis of migration samples supposes a great advantage in order to comply with the established regulation about migrants and to decrease the false non-compliant results.

Influence of Ambient Atmospheric Environments on the Mixing State and Source of Oxalate-Containing Particles at Coastal and Suburban Sites in North China

Photodegradation is a key process impacting the lifetime of oxalate in the atmosphere, but few studies investigated this process in the field due to the complex mixing and sources of oxalate. Oxalate-containing particles were measured via single-particle aerosol mass spectrometry at coastal and suburban sites in Qingdao, a coastal city in North China in the summer of 2016. The mixing state and influence of different ambient conditions on the source and photodegradation of oxalate were investigated. Generally, 6.3% and 12.3% of the total particles (by number) contained oxalate at coastal and suburban sites, respectively. Twelve major types of oxalate-containing particles were identified, and they were classified into three groups. Biomass burning (BB)-related oxalate–K and oxalate–carbonaceous particles were the dominant groups, respectively, accounting for 68.9% and 13.6% at the coastal site and 72.0% and 16.8% at the suburban site. Oxalate–Heavy metals (HM)-related particles represented 14.6% and 9.3% of the oxalate particles at coastal and suburban sites, respectively, which were mainly from industrial emissions (Cu-rich, Fe-rich, Pb-rich), BB (Zn-rich), and residual fuel oil combustion (V-rich). The peak area of oxalate at the coastal site decreased immediately after sunrise, while it increased during the daytime at the suburban site. However, the oxalate peak area of Fe-rich particles at both sites decreased after sunrise, indicating that iron plays an important role in oxalate degradation in both environments. The decay rates (k) of Fe-rich and BB-Fe particles at the coastal site (−0.978 and −0.859 h−1, respectively), were greater than those at the suburban site (−0.512 and −0.178 h−1, respectively), owing to the high-water content of particles and fewer oxalate precursors. The estimated k values of oxalate peak area for different ambient conditions were in the same order of magnitude, which can help establish or validate the future atmospheric models.