Current Analytical Chemistry - Volume 21, Issue 5, 2025

In the current investigation, derivatives incorporating pyrazole and thiadiazole ring systems were designed, and docking studies were conducted to elucidate their potential binding mode. Antimicrobial Resistance (AMR) is a critical threat to global public health and development, recognized by the World Health Organization (WHO) as one of the top 10 risks worldwide.

The objective was to develop new antimicrobial drugs that can effectively target a wide range of resistant microbes.

The designed derivatives were docked using AutoDock Vina 4.2 against the active sites of Staphylococcus aureus DHFR (2W9H), Staphylococcus aureus GyrB (4URO), Staphylococcus aureus thymidylate kinase (4QGG) for antibacterial activity and Candida albicans DHFR (1M78), Candida albicans aspartic protease 2 (3PVK), Candida albicans N-myristoyl transferase (1IYK) for antifungal activity.

The designed derivatives underwent further assessment for in silico physicochemical properties, and drug-likeness.

Several of the derivatives exhibited notable anti-microbial activity, demonstrating a potency on par with the Standard drug Ciprofloxacin and Fluconazole. The results, evaluated based on docking scores into the receptor's active site, suggested that the most active derivatives, W36 and W33, may act as promising antibacterial against 2W9H and antifungal against 1IYK, respectively.

pH indicators have long been utilized for rapid pH determination, relying on color changes to indicate pH values. However, visual color detection suffers from low sensitivity due to the limitations of the human eye. In this study, we explored the use of pyrylium compounds as pH indicators.

Three pyrylium compounds were synthesized, and their pH-dependent UV-Vis absorption and color changes were investigated. UV-Vis absorption studies revealed distinct pH-dependent changes, enabling the compounds to function as dual-transition pH indicators. The pKa values of these indicators can be tuned by changing the substituent on the chromophore core.

Principal component analysis of the mixture of these three compounds demonstrated the ability of the system to measure pH with high precision, making it suitable for real sample analysis. Smartphone-assisted analysis was employed to exploit the potential of these indicators for wide-range (4.0-13.5) pH determination.

The obtained results demonstrated for the first time that pyrylium compounds can be used as dual-transition pH indicators. By modifying the substituents on this chromophore, indicators operating in different pH ranges can be obtained and utilized in smartphone-assisted pH detection.

A simple and effective method to separate chlorogenic acid from Eucommia ulmoides leaves with macroporous resin was studied in this paper.

In order to optimize the separation process of chlorogenic acid from Eucommia ulmoides leaves, dynamic adsorption and desorption experiments were carried out on a glass column filled with XDA-8 resin. Based on the First-principles calculation, the possible adsorption models were simulated.

Among the six macroporous resins, XDA-8 showed good adsorption/desorption capacity and a high adsorption/desorption ratio for chlorogenic acid. After being treated with XDA-8 resin once, the content of chlorogenic acid from the extraction increased by 525%, and the recovery of chlorogenic acid reached 85.36%.

At 25°C, the adsorption behavior of chlorogenic acid on XDA-8 resin was consistent with the Langmuir isotherm model and pseudo-second-order kinetic model. Furthermore, by calculating the charge changes of the O atom at each position in the chlorogenic acid molecule and the H atom at the adsorption site in polystyrene molecule with resin skeleton, and combining with the electron cloud density distribution diagram of chlorogenic acid and resin skeleton, the adsorption of chlorogenic acid by XDA-8 resin is mainly due to the charge transfer, which causes the electron cloud to overlap.

Given the rapid increase in serious infectious and inflammatory diseases in the general population worldwide, it is vital to advance our understanding of the process of infection and inflammation.

These illnesses can be treated by diverse cytokines, chemokines, and chemical compounds, but how to find and identify effective protein drugs is unknown. In this study, large–scale analytical approaches, such as high–throughput chips with RNA-Seq that construct the protein regulatory networks, were established.

NLRP2:shRNA (1–3) and GFP: Control lentivirus were fabricated to infect Human Brain Microvascular Endothelial Cells (HBMEC) to knock down NLRP2 gene that not only possesses bio-chemical activity but also bio-mechanical properties. Once HBMEC was loaded on the 18mmX18mm circular soft cover slip, by knocking down NLRP2 gene and adding puromycin, a large number of cytokines were secreted to activate both autophagy and endosome vesicle signaling by KEGG pathway analysis, which was successfully detected by both ELISA approach and QAH-Neu-1 chip, but no secretion from GFP: Control.

It was demonstrated that the NLRP2 gene was highly responsive to cytokines. The protein regulatory network from RNA–Seq platform demonstrated that the secretion by knocking down the NLRP2 gene was highly correlated with autophagy, endosome, multivesicular body, phosphatidylinositol, and necrosis signalling pathway. Furthermore, most of the cytokines expressed were found to be specific for intracellular vesicle–dependent secretion, leading to obvious cell swelling and shedding, membrane protein dotting to nucleation, and actin dynamics. Interestingly, it was also found that autophagy, together with endosome signalling, was collectively activated to boost the secretion to cause a “cytokine storm”, which led to lipid phase separation.

This study proposed high throughput approaches centered on the NLRP2 gene network for many severe diseases, providing novel insight into biological pathways influencing infection and inflammation (e.g., COVID-19/E.coli). They can be modulated as potential therapeutic targets and used as biomarkers in the diagnosis and treatment of many diseases to promote human health. This increases our interest in developing new leadless-peptides at the genomics and proteomics levels to obtain cytokines and chemokines for micro-array constructions (VirD‒cytokines, VirD‒enzymes, VirD‒polymers) by membane protein fusion strategy, antibody and vaccine development for infections, diabetes, cardiovascular disease, atherosclerosis, non–alcoholic fatty liver, auto-immune, neurodegenerative disorder, and even cancer-related disease therapy. They have the most valuable applications in molecular diagnosis, protein marker discovery, and bio-therapy.

Pharmaceutical companies must adhere to rules established by regulatory agencies in order to monitor pharmaceutical products for nitrosamine contamination. One type of nitrosamine that can arise during the manufacture of the drug’s formulation and substance is N-Nitroso Tofacitinib. One pollutant that causes cancer is nitrosamines. Controlling the amount of nitrosamines in pharmaceuticals and medical supplies is essential. In this study, we devised a straightforward, sophisticated LC-MS/MS approach to analyse N-Nitroso Tofacitinib present in Tofacitinib tablets.

Liquid Chromatography-Tandem Mass Spectrometry (LC-MS/MS) experiments were optimised on Jade C18 (5 µ, 150 x 4.6 mm), solvent mixture was operated in gradient program using 10 mM ammonium acetate pH 3.2 and acetonitrile with 1.0 mL flow rate. Mass transition (m/z) 275.3/149.1, 275.3 /147.0, and 275.3/82.1 are used.

The range of linearity is 0.7 - 20.0 ng/mL, with R² of 0.9952. The Lowest Detection (LOD) and quantification (LOQ) were 0.7 ng/mL and 1.0 ng/mL respectively. The recovery repeatability was found to be within the specified range.

The new approach proved effective for quantifying N-Nitroso Tofacitinib impurity in Tofacitinib Tablet samples, indicating that it could be applied for regular analysis.

Rubus alceifolius poir leaves are a widely distributed medicinal plant material in the Eastern Hemisphere. However, there has been no report regarding their chemistry until now.

Fresh R. alceifolius leaves were treated using a set of experimental protocols to prepare a lyophilized aqueous extract. Subsequently, the extract was qualitative and quantitatively analyzed using the database-affinity ultra-high-performance liquid chromatography-quadrupole-Exactive-Orbitrap-tandem mass spectrometry (UHPLC-Q-Exactive-Orbitrap-MS/MS) technology.

Based on MS/MS elucidation and comparison with the database in UHPLC-Q-Exactive-Orbitrap-MS/MS apparatus, 33 compounds were qualitatively identified. Especially, 12 isomers were strictly distinguished, including apigenin vs. 2'-hydroxydaidzein, luteolin 7-O-glucuronide vs. scutellarin, (+) catechin vs. (-) epicatechin, 3-O-caffeoylquinic acid vs. 4-O-caffeoylquinic acid vs. 5-O-caffeoylquinic acid, and 3,4-O-dicaffeoylquinic acid vs 3,5-O-dicaffeoylquinic acid vs. 4,5-O-dicaffeoylquinic acid. In addition, 21 non-isomeric compounds, such as ellagic acid and gallic acid, were also found under negative or positive ion models. The quantitative analysis suggested that ellagic acid was found to be of the highest level (133.00 ± 3.50 µg/g), while (+)-4-cholesten-3-one was calculated to be of the lowest level (0.035 ± 0.0050 µg/g).

These findings will help to understand the substance basis of the traditional medicinal functions of R. alceifolius leaves and to find their suitable quality markers.

Recently, bimetallic metal-organic frameworks (MOFs) have gained significant attention for their potential in treating industrial wastewater. The rapid increase in industrialization worldwide has resulted in the continual discharge of organic dyes in aquatic ecosystems. These dyes disrupt aquatic ecosystems and are hazardous for human beings. Thus, there is a considerable demand to design a framework for the removal of contaminants from wastewater. For this purpose, this study focuses on synthesizing BM-MOF@PC and investigating its efficacy in removing methyl orange (MO) and congo red (CR).

A novel, low-cost, eco-friendly Zn and Co-based bimetallic MOF (BM-MOF) modified polyaniline and cellulose acetate (PC) were synthesized based on electrospun (BM-MOF@PC) nanofibers. The prepared BM-MOF@PC was characterized by SEM, XRD, FTIR, and N2 adsorption-desorption isotherm. The smooth formation of BM-MOF@PC nanofibers generates high adsorption capability by exposing the maximal active site for the adsorption at the entire surface. The adsorption capability of synthesized BM-MOF@PC nanofibers was evaluated against MO and CR dyes from an aqueous phase.

The maximum adsorption capacity of MO and CR at the surface of BM-MOF@PC nanofibers were 636.9 and 313.05 mg/g, respectively. Several adsorption parameters, including initial dye concentration, contact time, temperature, the adsorbent's doses, and pH's effect on adsorption kinetics, were investigated. The ability of BM-MOF@PC nanofibers to adsorb MO and CR at various pHs indicated that several attraction forces, including electrostatic interaction, hydrogen bonding, and π-π interactions, could be involved in the dye removal.

The fabricated material BM-MOF@PC nanofibers have a large surface area compared to BM-MOF, which indicates the more active sites for the adsorption of MO and CR dyes. Moreover, the BM-MOF@PC nanofibers demonstrated robust reusability towards MO and CR adsorption across five cycles, which suggested that our fabricated material is more stable and economically reliable in real-time applications.

Amidst the identification of numerous secondary chemicals from Euphorbia neriifolia, there is a desperate need for the development of primary metabolite separation techniques.

In order to do that, bioactive chemicals from Euphorbia neriifolia (L.) leaf were extracted, isolated, and characterized. Subsequently, their antioxidant activity was evaluated.

In this study, the determination of linoleic acid (LA) in petroleum ether extract (PEE) of Euphorbia neriifolia leaf (ENL) was carried out the first time by using thin-layer chromatography (TLC) and high-performance thin-layer chromatography (HPTLC) methods.

The chromatographic analysis of the PEE of ENL shows better spots and well-separated peak of LA with 0.49 retention factor (Rf) value and 22.54 ng LA content. The linearity of the calibration curve ranges from 5-25 ng spot^-1 with a high correlation coefficient. The proposed method was characterized by better accuracy close to 99.5%, well robustness, and good precision range from 0.183% (intra-day) to 0.242% (inter-day). The percentage (%) RSD, which determined the stability of standard LA, did not exceed 2% after time period of 12, 24, 36, 48, and 72 h. The GC-MS analysis revealed the presence of different types of low or high-molecular-weight phytocompounds of varying quantities from the fractions of ENL. The FT-IR spectrum of ICs showed various peaks that confirmed the presence of C=C bending, C-H stretching, O-H stretching, CH2 stretching, and a carboxyl group. The ¹H-NMR spectrum of the ICs from ENL confirmed the presence of octadecanoic in IC1, L-(+)-ascorbic acid dihexadecanoate in IC2, hexadecanoic acid in IC3, linoleic acid in IC4, and oleic acid in IC5, respectively. IC4 showed greater antioxidant activity in comparison to other compounds with an IC50 value of 3.9 ± 0.01 µg mL^-1.

Thus, the present study identified five different phytocompounds that may be utilized as an effective option for the cure of different diseases.