High Percentage Of Recovery Research Articles

A novel potentiometric approach for the sensitive detection of cadmium in real samples using modified carbon paste electrodes

AbstractThe goal of this study was to demonstrate a novel potentiometric technique for the measurement of Cd(II) ion. A new ionophore called [5′‐(ethane‐1,2‐diylbis(sulfanediyl))bis(3‐phenyl‐4H‐1,2,4‐triazol‐4‐amine) (ESPTA)] was prepared and used as an electroactive material in the fabrication of new carbon paste electrode (CPE) for the quantification of Cd(II) ion. The paste was prepared by mixing ESPTA, graphite, graphene, and TCP or o‐NPOE as a plasticizer in different weight percent ratios. The developed electrodes I, II, III, and IV showed divalent Nernstian response of 29.80±0.05, 29.80±0.08, 29.86±±0.04 and 29.75±0.33 mV decade−1 over the concentration ranges of 1.0×10−5–1.0×10−1, 1.0×10−8–1.0×10−1, 1.0×10−6–1.0×10−1 and 1.0×10−7–1.0×10−1 mol L−1 with percentage of (2.65 ESPTA: 66.32 graphite: 31.03 TCP), (2.65 ESPTA: 13.27 graphite : 53.05 graphene : 31.03 TCP), (2.75 ESPTA: 68.68 graphite: 28.57 o‐NPOE) and (2.75 ESPTA: 13.74 graphite : 54.94 graphene : 28.57 o‐NPOE), for electrodes I, II, III, and IV, respectively. In order to improve the performance characteristics of electrodes I, II, III, and IV, response time, the effect of temperature, and pH were examined. The electrodes showed high selectivity for Cd(II) over different mono‐, di‐ or trivalent cations. These modified electrodes were applied for the determination of the concentration of Cd(II) in different real samples like Nido Milk, juice extractions and tap water samples with high percentage recovery. The F‐ and t‐test values showed that there is no statistically significant difference between the results obtained and those from the stated method of inductively coupled plasma. Low standard and relative standard deviation values, good percentage recovery, and modest detection and quantification limitations were all displayed by the electrodes. The outcomes showed the potentiometric method‘s effectiveness in detecting Cd(II) in actual samples and its potential for use in routine analysis.

A powerful combination of liquid chromatography-triple quadrupole mass spectrometry and quadruple isotope dilution strategy for the determination of fenuron at trace levels in river water, stream water and fruit juice samples

An accurate, sensitive, and rapid analysis methodology for the determination of fenuron at ultratrace levels in river water, stream water and fruit juice samples was developed based on quadruple isotope dilution (ID4) and liquid chromatography-triple quadrupole mass spectrometry (LC-MS/MS) system. Fenuron-d6 as isotopically labelled material (ILM) was synthesized in our laboratory to apply the ID4 method. Optimization studies were performed to find experimental conditions for the separation and detection of fenuron at trace levels. Analytical performance parameters such as limit of detection (LOD), limit of quantitation (LOQ) and linear range were determined by external calibration strategy. LOD and LOQ values for the analyte were found at ppt levels and a wide linear range was obtained in the range of 0.11 – 492.4 µg/kg. Recovery studies were also carried out for water and fruit juice samples to test applicability and accuracy of the developed LC-MS/MS system. ID4 strategy was applied to the selected samples to increase accuracy of the developed method and tolerate high matrix effects for fruit juice samples. According to high percent recoveries and low relative standard deviation values, the developed LC-ID4-MS/MS system was proven as an accurate, precise and sensitive analytical method for the quantification of fenuron at trace levels.

Facile Chemical Synthesis of Co-Ru-Based Heterometallic Supramolecular Polymer for Electrochemical Oxidation of Bisphenol A: Kinetics Study at the Electrode/Electrolyte Interface.

Regardless of the adverse effects of Bisphenol A (BPA), its use in industry and in day-to-day life is increasing at a higher rate every year. In the present study, a simple and reliable chemical approach was used to develop an efficient BPA sensor based on a Co-Ru-based heterometallic supramolecular polymer (polyCoRu). Surface morphology and elemental analysis were examined using scanning electron microscopy (SEM) and energy-dispersive X-ray spectroscopy (EDX). Furthermore, functional group analysis was accomplished by Fourier transform infrared spectroscopy (FT-IR). UV-vis spectroscopy was used to confirm the complexation in the ratio of 0.5:0.5:1 (metal 1/metal 2/ligand). Electrochemical characterization of the synthesized polyCoRu was conducted using cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS) analyses. The study identified two distinct linear dynamic ranges for the detection of BPA, 0.197-2.94 and 3.5-17.72 μM. The regression equation was utilized to determine the sensitivity and limit of detection (LOD), resulting in values of 0.6 μA cm-2 μM-1 and 0.02 μM (S/N = 3), respectively. The kinetics of BPA oxidation at the polyCoRu/GCE were investigated to evaluate the heterogeneous rate constant (k), charge transfer coefficient (α), and the number of electrons transferred during the oxidation and rate-determining step. A probable electrochemical reaction mechanism has been presented for further comprehending the phenomena occurring at the electrode surface. The practical applicability of the fabricated electrode was analyzed using tap water, resulting in a high percentage of recovery ranging from 96 to 105%. Furthermore, the reproducibility and stability data demonstrated the excellent performance of polyCoRu/GCE.

Applicability of fluorescamine as a fluorogenic reagent for highly sensitive fluorimetric analysis of the tyrosine kinase inhibitor (avapritinib) in pharmaceuticals and biological samples.

Avapritinib (AVP) was the first precision drug to be approved by the US Food and Drug Administration (FDA) in 2020 for patients suffering from metastatic gastrointestinal stromal tumors (GISTs) and progressive systemic mastocytosis. The analysis of AVP in pharmaceutical tablets and human plasma was then carried out using a fast, efficient, sensitive, and simple fluorimetric method using a fluorescamine reagent. The procedure is based on the interaction between fluorescamine as a fluorogenic reagent and the primary aliphatic amine moiety in AVP using borate buffer solution at pH8.8. The produced fluorescence was measured at 465 nm (Excitation at 395 nm). The calibration graph's linearity range was discovered to be 45.00-500.0ng mL-1 . Utilizing the International Council for Harmonization (ICH) and US-FDA recommendations, the research technique was validated and bioanalytically validated. The proposed approach was effectively employed for determining the stated pharmaceuticals in plasma with a high percentage of recovery ranging from 96.87 to 98.09 and pharmaceutical formulations with a percentage of recovery equal to 102.11% ± 1.05%. In addition, the study was extended to a pharmacokinetic study of AVP with 20 human volunteers as a step for AVP management in therapeutic cancer centers.

Development of a novel microdevice for sorptive extraction under a green analytical chemistry approach: Application for bioanalytical determination of Ibuprofen

This study proposes a novel device called micro polymeric magnetized bar adsorptive extraction (µ-PMBAE), as an extraction and enrichment technique for trace analysis in aqueous samples. These micro-bar absorbent devices were prepared using easily accessible and low-cost materials, incorporating different sorbent materials into a polymer and introducing a small piece of neodymium magnet. Several stability tests were applied to determine their robustness, stability, and weight variation; finally, ibuprofen concentration in urine samples was determined, demonstrating the applicability of extraction devices under a green analytical chemistry approach. The µ-PMBAE showed remarkable advantages since different sorbents can be added to the hot melt glue. This tunes the interaction with the analytes to become more specific in the extraction. Likewise, the magnetic ability makes it possible to carry out extraction without using an extra stir bar, matching its performance with the traditional commercially based on polydimethylsiloxane phase. The proposed analytical method demonstrated excellent performance concerning high recovery percentages, adequate coefficients of variation, and low detection limits.

Development of a novel microdevice for sorptive extraction under a green analytical chemistry approach: Application for bioanalytical determination of Ibuprofen

This study proposes a novel device called micro polymeric magnetized bar adsorptive extraction (µ-PMBAE), as an extraction and enrichment technique for trace analysis in aqueous samples. These micro-bar absorbent devices were prepared using easily accessible and low-cost materials, incorporating different sorbent materials into a polymer and introducing a small piece of neodymium magnet. Several stability tests were applied to determine their robustness, stability, and weight variation; finally, ibuprofen concentration in urine samples was determined, demonstrating the applicability of extraction devices under a green analytical chemistry approach. The µ-PMBAE showed remarkable advantages since different sorbents can be added to the hot melt glue. This tunes the interaction with the analytes to become more specific in the extraction. Likewise, the magnetic ability makes it possible to carry out extraction without using an extra stir bar, matching its performance with the traditional commercially based on polydimethylsiloxane phase. The proposed analytical method demonstrated excellent performance concerning high recovery percentages, adequate coefficients of variation, and low detection limits.

Utility of eco-friendly microwave-assisted nitrogen-doped carbon dots as a luminescent nano-sensor for the ultra-sensitive analysis of tigecycline in dosage form and biological samples

In the presented work, simple, green, sensitive, and selective nitrogen-doped carbon quantum dots (N-CQDs) were developed as nano-sensor for quantification of tigecycline (TIG) in different matrices. The proposed method is based on microwave synthesis of green nitrogen-doped carbon quantum dots with a high quantum yield (41.39%) and size diameter equal to 2.0 nm from the green juice of Eruca sativa leaves. The relative fluorescence intensity (RFI) of the green synthesized quantum dots (N-CQDs) was quenched at emission 512 nm (excitation 445 nm) after the addition of TIG drug. A good linear range between TIG concentration and quenched fluorescence intensity of N-CQDs in the range 20–300 ng mL−1, with the lower limit of quantitation (LOQ) equal to 8.51 ng mL−1. The proposed method was validated using the international conference of harmonization (ICH) recommendation and bio-analytical validation using U.S. food and drug administration (US-FDA) guidelines. The N-CQDs have been fully characterized using a transmission electron microscope (TEM), dynamic light scattering (DLS), X-Ray photoelectron spectroscopy (XPS), and Fourier-transform infrared spectrometer (FTIR). The suggested technique is a straightforward analytical procedure that can be used in clinical laboratories. Under the optimum condition, TIG was estimated in human plasma with a high percentage of recovery ranging from 96.95 to 98.54%. In addition, the proposed method was applied effectively in milk samples with percentage of recovery equal to 98.90 ± 1.55.

Comprehensive quantification of flavonoids and salicylic acid representative of Salix spp. using microLiquid Chromatography-Triple Quadrupole Mass Spectrometry: the importance of drying procedures and extraction solvent when performing classical solid-liquid extraction

Willow (Salix spp.) is gaining an increasing interest as a fast-growing tree with high biomass yield from low agricultural inputs, which contains potentially bioactive compounds. The present work aimed to develop a high-yield extraction procedure combined with robust, sensitive and fast microLiquid Chromatography-Triple Quadrupole Mass Spectrometry (LC-MS/MS) based method for comprehensively quantifying flavonoids and salicylic acid in the bark of Salix spp. We have investigated the effect of freeze- and oven-drying procedures and five extraction solvents on the yield of individual flavonoid and salicylic acid when performing classical solid-liquid extraction. The freeze-drying was the best drying procedure for preserving monomeric and polymeric flavan-3-ols, whereas other flavonoids were less affected. Salicylic acid was not affected by the drying procedures. The best extraction solvent in terms of the yield of individual flavonoid among the tested solvents in this study was the combination of methanol acidified with 1% hydrochloric acid. LC-MS/MS method has shown a high recovery percentage (≥80%), good precision and overall robustness.

New analytical LC–MS/MS method for fluconazole and ivermectin estimation in combined pharmaceutical dosage form: development and validation

BackgroundFluconazole, an antifungal drug, prevents fungi growth by inhibiting the formation of a protective covering. Ivermectin has several biological activities, such as antibacterial, antiviral, and anti-cancer characteristics, and offers various therapeutic outcomes. There are several commercial products containing these two drugs. Therefore, developing a method that can allow the simultaneous estimation of Fluconazole and ivermectin is inevitable to monitor them in commercial dosage forms. The hyphenated methodology that combines spectroscopic and chromatographic techniques is gaining high interest in the pharmaceutical industry. Consequently, the objective of present research work was to investigate robust and sensitive LC–MS/MS avenue for simultaneous determination of Fluconazole and ivermectin in pure material and combined dosage form.ResultsThe simultaneous quantification of Fluconazole and ivermectin in tablet dosage form has been developed and validated using a straightforward, sensitive, practical, and repeatable LC–MS/MS approach. The separation was performed using a C18 (150 × 4.6 mm) column, injection volume of 10 µL, and elution with acetonitrile: formic acid at a ratio of 70:30, with the column temperature at 30 °C, and a flow rate of 4.0 mL/min. The retention times of Ivermectin and Fluconazole were 1.10 min and 1.05 min, respectively. The calibration curves for Fluconazole and ivermectin demonstrated significant linearities indicated by the correlation coefficients (r2 = 0.999 and r2 = 0.997) and precision (% R.S.D. of 1.58 and 1.13). The linear correlation between peak area and concentration allowed high percentage recoveries of 98.5%–99.4% and 97.8%–99.3% for Fluconazole and Ivermectin, respectively. The L.O.D.s for Fluconazole and ivermectin were found to be 0.0034 and 0.074 g/mL, respectively. The L.O.Q.s for Fluconazole and ivermectin were 0.010 and 0.225 g/mL, respectively.ConclusionAll the analytical parameters were identified and found to be within the acceptable range set forth by the ICH guidelines, demonstrating the devised method's acceptability in the simultaneous detection and estimation of Fluconazole and ivermectin in the commercial dosage forms.

Analysis of Methylphenol Concentration in Selangor Rivers, Malaysia using Solid Phase Extraction Technique Coupled with UV-Vis Spectroscopy

Methylphenol is extensively produced from pharmaceuticals, agriculture, textiles, cosmetics, and petrochemicals industries. It is a pollutant that can adversely affect public health and the ecosystem. Following the issues raised, methylphenol extraction from Selangor rivers need to be done to avoid adverse consequences. In this study, solid phase extraction (SPE) combined with ultraviolet-visible spectroscopy (UV-Vis) detection at 271 nm was utilized to extract methylphenol from Selangor rivers. The challenges reported by applying the SPE technique was to identify the optimum conditions for extraction to guarantee effective recovery of the extracted methylphenol. Therefore, this research aimed to develop an extraction technique to extract methylphenol from Selangor rivers. In this study, 3 mL Supel Swift-HLB cartridges with bed weight of 60 mg were used as SPE cartridges. The optimum conditions for methylphenol SPE were 3 mL methanol as a conditioning solvent, 6 mL of pH 5 water sample with a contact time of 4 min with adsorbent bed was practiced during sample loading, 3 mL of acetonitrile as washing solvent, and 12 mL of acetone as the elution solvent. The concentrations of methylphenol detected at five different locations collected from Sungai Klang, Sungai Selangor, and Sungai Langat ranged from 5 to 6 mg L-1. SPE coupled with UV-Vis is an appropriate method for methylphenol extraction as it simplifies sample preparation, is time saving, and can achieve a high percentage recovery of methylphenol.

Occurrence, distribution, and risk assessment of parabens in the surface water of Terengganu River, Malaysia

The concentration, distribution, and risk assessment of parabens were determined in the surface water of the Terengganu River, Malaysia. Target chemicals were extracted via solid-phase extraction, followed by high-performance liquid chromatography analysis. Method optimization produced a high percentage recovery for methylparaben (MeP, 84.69 %), ethylparaben (EtP, 76.60 %), and propylparaben (PrP, 76.33 %). Results showed that higher concentrations were observed for MeP (3.60 μg/L) as compared with EtP (1.21 μg/L) and PrP (1.00 μg/L). Parabens are ubiquitously present in all sampling stations, with >99 % of detection. Salinity and conductivity were the major factors influencing the level of parabens in the surface water. Overall, we found no potential risk of parabens in the Terengganu River ecosystem due to low calculated risk assessment values (risk quotient < 1). In conclusion, parabens are present in the river, but their levels are too low to pose risks to aquatic organisms.

LC-MS/MS bioanalytical method for the quantitative analysis of nifedipine, bisoprolol, and captopril in human plasma: Application to pharmacokinetic studies.

In this study, the development and validation of an accurate and highly sensitive LC-MS/MS method were performed for the estimation of nifedipine, bisoprolol and captopril in real human plasma. Liquid-liquid extraction using tert-butyl methyl ether was efficiently applied for extraction of the analytes from plasma samples. The chromatographic separation was carried out using an isocratic elution mode on the X-terra MS C18 column (4.6 × 50 mm, 3.5μm). The mobile phase consisted of methanol-0.1% formic acid (95:5, v/v) for determination of nifedipine and bisoprolol and acetonitrile-0.1% formic acid (70:30, v/v) for determination of captopril with a flow rate of 0.5ml/min. Acceptable results regarding the different validation characteristics of the analytes were obtained in accordance with US Food and Drug Administration recommendations for bioanalytical methods. The developed approach was linear over concentration ranges of 0.5-130.0, 50.0-4,500.0 and 0.3-30.0ng/ml for nifedipine, captopril and bisoprolol, respectively. The method revealed a sufficient lower limit of quantification in the range of 0.3-50.0ng/ml, as well as high recovery percentages, indicating high bioanalytical applicability. The proposed method was efficiently applied to a pharmacokinetic evaluation of a fixed-dose combination of the analytes in healthy male volunteers.

Simultaneous electrochemical determination of persistent petrogenic organic pollutants based on AgNPs synthesized using carbon dots derived from mushroom

Polycyclic aromatic hydrocarbons (PAHs) are highly carcinogenic substances and accumulate in water bodies through various industries. Due to their harmful effects on humans, it is very important to monitor PAHs in various water resources. In the present work, we report an electrochemical sensor based on silver nanoparticles synthesized using mushroom-derived carbon dots for the simultaneous determination of anthracene and naphthalene, for the first time. Pleurotus species mushroom was used to synthesize the carbon dots (C-dots) via the hydrothermal method and these C-dots were used as a reducing agent for the synthesis of silver nanoparticles (AgNPs). The synthesized AgNPs have been characterized through UV–Visible and FTIR spectroscopy, DLS, XRD, XPS, FE-SEM, and HR-TEM. Well-characterized AgNPs were used to modify glassy carbon electrodes (GCEs) by the drop-casting method. Ag-NPs/GCE has shown strong electrochemical activity towards the oxidation of anthracene and naphthalene at well-separated potentials in phosphate buffer saline (PBS) at pH 7.0. The sensor exhibited a wide linear working range of 250 nM to 1.15 mM for anthracene and 500 nM to 842 μM for naphthalene with the corresponding lowest detection limits (LODs) of 112 nM and 383 nM respectively with extraordinary anti-interference ability against many possible interferents. The fabricated sensor showed high stability and reproducibility. The usefulness of the sensor for the monitoring of anthracene and naphthalene in a seashore soil sample has been demonstrated by the standard addition method. The sensor gave better results with a high recovery percentage indicating the first-ever device to detect two PAHs at the single electrode with the best analytical results.

Simultaneous Determination of Ceftazidime in Three Different Pharmaceutical Preparations Combined with Either Tazobactam, Tobramycin or Sulbactam by HPTLC-Spectrodensitometric Method.

A new, simple hight performance thin layer chromatography (HPTLC)-Spectrodensitometric strategy was created and approved for the synchronous estimation of four antibacterial specialists: ceftazidime (CEF), tazobactam (TAZ), tobramycin (TOB) and sulbactam (SUL). The four compounds were separated on TLC aluminum plates covered with silica gel 60F254, using chloroform-acetonitrile-methanol-ammonia (4:1:0.5:0.15, v/v/v/v) as a mobile phase at 254nm. Linear correlation was obeyed over the concentration ranges of 12.0-72.0, 2.0-12.0, 3.0-18.0 and 10.0-50.0μgmL-1 for CEF, TAZ, TOB and SUL, respectively. The proposed approach is efficient, repeatable and convenient as a flexible method for the quality control of diverse combinations of these pharmaceuticals in various pharmaceutical preparations, with high percent recoveries that are highly consistent with labeled data. When the findings of the proposed technique were compared to those of the comparison methods, there were no critical contrasts in terms of precision and accuracy.

A Novel Design Eco-friendly Microwave-assisted Cu–N@CQDs Sensor for the Quantification of Eravacycline via Spectrofluorimetric Method; Application to Greenness Assessments, Dosage Form and Biological Samples

Community-acquired pneumonia is one of the most common infectious diseases and a substantial cause of mortality and morbidity worldwide. Therefore eravacycline (ERV) was approved by the FDA in 2018 for the treatment of acute bacterial skin infections, GIT infections, and community-acquired bacterial pneumonia caused by susceptible bacteria. Hence, a green highly sensitive, cost-effective, fast, and selective fluorimetric approach was developed for the estimation of ERV in milk, dosage form, content uniformity, and human plasma. The selective method is based on the utilization of plum juice and copper sulphate for the synthesis of green copper and nitrogen carbon dots (Cu–N@CDs) with high quantum yield. The quantum dots' fluorescence was enhanced after the addition of ERV. The calibration range was found to be in the range 1.0 – 80.0 ng mL−1 with LOQ equal to 0.14 ng mL−1 and LOD was found to be 0.05 ng mL−1. The creative method is simple to deploy in clinical labs and therapeutic drug health monitoring system. The current approach has been bioanalytically validated using US-FDA and validated ICH criteria. High-resolution transmission electron microscopy (HR-TEM), X-ray photon spectroscopy (XPS), Zeta potential measurements, fluorescence, UV–VIS, and FTIR spectroscopy have all been used to fully characterize the Cu–N@CQDs. The Cu–N@CQDs were effectively applied in human plasma and milk samples with a high percentage of recovery ranging from 97.00 to 98.80%.

Expression, purification, and characterisation of the p53 binding domain of Retinoblastoma binding protein 6 (RBBP6).

RBBP6 is a 250 kDa eukaryotic protein known to be a negative regulator of p53 and essential for embryonic development. Furthermore, RBBP6 is a critical element in carcinogenesis and has been identified as a potential biomarker for certain cancers. RBBP6's ability to interact with p53 and cause its degradation makes it a potential drug target in cancer therapy. Therefore, a better understating of the p53 binding domain of RBBP6 is needed. This study presents a three-part purification protocol for the polyhistidine-tagged p53 binding domain of RBBP6, expressed in Escherichia coli bacterial cells. The purified recombinant domain was shown to have structure and is functional as it could bind endogenous p53. We characterized it using clear native PAGE and far-UV CD and found that it exists in a single form, most likely monomer. We predict that its secondary structure is predominantly random coil with 19% alpha-helices, 9% beta-strand and 14% turns. When we exposed the recombinant domain to increasing temperature or known denaturants, our investigation suggested that the domain undergoes relatively small structural changes, especially with increased temperature. Moreover, we notice a high percentage recovery after returning the domain close to starting conditions. The outcome of this study is a pure, stable, and functional recombinant RBBP6-p53BD that is primarily intrinsically disordered.

Marker-Assisted Pyramiding of Blast-Resistance Genes in a japonica Elite Rice Cultivar through Forward and Background Selection

Rice blast, caused by Pyricularia oryzae, is one of the main rice diseases worldwide. The pyramiding of blast-resistance (Pi) genes, coupled to Marker-Assisted BackCrossing (MABC), provides broad-spectrum and potentially durable resistance while limiting the donor genome in the background of an elite cultivar. In this work, MABC coupled to foreground and background selections based on KASP marker assays has been applied to introgress four Pi genes (Piz, Pib, Pita, and Pik) in a renowned japonica Italian rice variety, highly susceptible to blast. Molecular analyses on the backcross (BC) lines highlighted the presence of an additional blast-resistance gene, the Pita-linked Pita2/Ptr gene, therefore increasing the number of blast-resistance introgressed genes to five. The recurrent genome was recovered up to 95.65%. Several lines carrying four (including Pita2) Pi genes with high recovery percentage levels were also obtained. Phenotypic evaluations confirmed the effectiveness of the pyramided lines against multivirulent strains, which also had broad patterns of resistance in comparison to those expected based on the pyramided Pi genes. The developed blast-resistant japonica lines represent useful donors of multiple blast-resistance genes for future rice-breeding programs related to the japonica group.

Identification of genetic and biochemical mechanisms associated with heat shock and heat stress adaptation in grain amaranths.

Heat stress is poised to become a major factor negatively affecting plant performance worldwide. In terms of world food security, increased ambient temperatures are poised to reduce yields in cereals and other economically important crops. Grain amaranths are known to be productive under poor and/or unfavorable growing conditions that significantly affect cereals and other crops. Several physiological and biochemical attributes have been recognized to contribute to this favorable property, including a high water-use efficiency and the activation of a carbon starvation response. This study reports the behavior of the three grain amaranth species to two different stress conditions: short-term exposure to heat shock (HS) conditions using young plants kept in a conditioned growth chamber or long-term cultivation under severe heat stress in greenhouse conditions. The latter involved exposing grain amaranth plants to daylight temperatures that hovered around 50°C, or above, for at least 4h during the day and to higher than normal nocturnal temperatures for a complete growth cycle in the summer of 2022 in central Mexico. All grain amaranth species showed a high tolerance to HS, demonstrated by a high percentage of recovery after their return to optimal growing conditions. The tolerance observed coincided with increased expression levels of unknown function genes previously shown to be induced by other (a)biotic stress conditions. Included among them were genes coding for RNA-binding and RNA-editing proteins, respectively. HS tolerance was also in accordance with favorable changes in several biochemical parameters usually induced in plants in response to abiotic stresses. Conversely, exposure to a prolonged severe heat stress seriously affected the vegetative and reproductive development of all three grain amaranth species, which yielded little or no seed. The latter data suggested that the usually stress-tolerant grain amaranths are unable to overcome severe heat stress-related damage leading to reproductive failure.

Carbon Nanotube-Incorporated Nanofibers for Immunosensor Preparation against CD36.

The increased serum concentration of CD36 is significantly associated with atherosclerosis, insulin resistance, and diabetes mellitus. Currently, there is no sensor system used for the detection of CD36 in the clinical field. Therefore, there is a need to develop a sensor system for the detection of CD36. The large surface area/volume ratio and controllable surface conformation of electrospun nanofibers (ENs) make them highly attractive for immunosensor applications. In the present study, PS/MWCNT-PAMAM ENs were produced and used as an immobilization matrix of Anti-CD36. Thus, the electrochemical behavior of the developed nanocomposite-based ENs and their usage potential were investigated for immunosensor applications. First, an oxidized multiwall carbon nanotube (MWCNT-OH) was synthesized and modified with a polyamidoamine generation 3 (PAMAM G3) dendrimer. The synthesized MWCNT-PAMAM nanocomposite was mixed with polystyrene (PS) solutions at different ratios to produce bead-free, smooth, and uniform PS/MWCNT-PAMAM ENs. PS/MWCNT-PAMAM ENs were accumulated on a screen-printed carbon electrode (SPCE) using the electrospinning technique. A biofunctional surface on the PS/MWCNT-PAMAM EN-coated SPCE was created using carbodiimide chemistry by covalent immobilization of Anti-CD36. The analytic performance characteristics of the developed PS/MWCNT-PAMAM/Anti-CD36 immunosensor were determined by performing electrochemical measurements in the presence of the CD36 protein. The linear detection range was found to be from 5 to 40 ng/mL, and the limit of detection was calculated as 3.94 ng/mL for CD36. The developed PS/MWCNT-PAMAM/Anti-CD36 immunosensor also displayed high tolerance to interference substances, good repeatability, and high recovery percent (recovery%) for artificial blood serum analysis.

In vitro anti-obesity activity by pancreatic lipase inhibition - Simple HPLC approach using EVOO as natural substrate.

Pancreatic lipase (PL) is a key lipolytic enzyme in humans for the digestion and absorption of dietary fats. Thereby, PL is a well-recognized target in the management of obesity and its inhibition attracts the interest of researchers globally. The screening of new natural PL inhibitors as alternative strategy to the synthesis of chemical ones represents nowadays a hot topic in research. The main challenge in this matter is the lack of a universal analytical method allowing the monitoring of PL activity and the reliable quantification of lipid digestion products. The (normal phase)-high-performance liquid chromatography-evaporative light scattering detector [(NP)-HPLC-ELSD] method proposed in this work represents a direct and rapid strategy to simultaneously quantify the products obtained from in vitro PL digestion. As one of the main novelties, the triacylglycerol (TAG) fraction from extra-virgin olive oil was selected as natural substrate. The PL activity was measured by monitoring the levels of remaining TAGs and formed free fatty acids (FFAs), using Orlistat as known inhibitor. The method validation confirmed the adequacy of the analytical method for quantitative purposes, showing high recovery percentage values (between 99% and 103%) and low relative standard deviation (RSD%) values (between 2% and 7%) for triolein and oleic acid standard solutions, as well as appreciably low limit of detection (LOD) and limit of quantification (LOQ) values (respectively 58 and 177 ng mL-1 for triolein; 198 and 602 ng mL-1 for oleic acid). Finally, the developed HPLC-ELSD method was successfully applied to evaluate the inhibitory effect of a polyphenolic extract obtained from apple pomace. The results showed a comparable inhibition degree between a 4.0mg mL-1 apple pomace solution and a 1.0μg mL-1 Orlistat solution. The proposed innovative method reveals highly sensitive and simple to follow the fate of PL digestion, thus opening the way to further investigations in the research of new potentially anti-obesity compounds. © 2022 Society of Chemical Industry.