Current Analytical Chemistry - Online First

L-cysteine (L-Cys) and homocysteine (Hcy) are the most representative of biothiol, which exist widely in organisms. L-Cys is one of the essential amino acids, which can be absorbed from protein-rich food and plays a considerable role in various physiological processes. Hcy is a vital intermediate in normal mammalian metabolism of methionine but does not occur in the diet. Therefore, it is significant to exploit a rapid and sensitive strategy to measure L-Cys and Hcy.

Herein, we designed an “on-on” fluorescent platform for detecting L-Cys and Hcy with gold nanoclusters (AuNCs) as probes. During the sensing process, cadmium ions (Cd²⁺) acted as mediating substances to connected AuNCs and L-Cys (or Hcy), and triggered aggregation-induced emission (AIE) effect.

The linear ranges achieved with fluorimetry of L-Cys and Hcy were 0.1-10.0 μM and 0.1-20.0 μM, respectively. Moreover, this fluorescent probe was successfully used to determine the L-Cys concentration in actual samples, and showed excellent recovery.

Furthermore, the mechanism for sensing L-Cys and Hcy has been exhaustively investigated.

Despite the widespread use of Ephedra altissima plant in traditional Algerian medicine, the biological potential of this species has still not been well explored.

This study, for the first time, focused on determining the effect of extraction methods and solvents on the phenolic content and antioxidant ability of the aerial part of Ephedra altissima.

Extraction was carried out by maceration and Soxhlet using the solvents H2O, Methanol/H2O and Petroleum ether. The chemical profile of E. altissima was determined by a qualitative HPLC/UV–Visible, and the antioxidant potential was evaluated by in vitro and in-silico studies.

The aqueous extract obtained by maceration exhibited the greatest total phenol content, while the petroleum ether prepared by Soxhlet extraction demonstrated the highest total flavonoid and condensed tannin contents. The HPLC profile showed the presence of a variety of phenolic compounds. The in-vitro assay results indicated good antioxidant potential. Gallic acid and sinapic acid were highlighted as the most potent antioxidants in the Soxhlet hydro-methanolic and petroleum ether extracts, respectively, according to the machine learning model. Molecular docking predicted the possible antioxidant potential of E. altissima phytocompounds by the interaction with human peroxiredoxin 5, and epicatechin was the most effective ligand. Molecular dynamics simulations confirmed the stability of the epicatechin-Prdx5 complex. Multivariate analysis was used to categorize the Ephedra altissima extracts into three groups according to their phenolic compound content and in vitro antioxidant ability.

Overall, the results of the present study revealed that the choice of solvent and extraction technique directly influence the biomolecule content and bioactivity of Ephedra altissima aerial part extracts.

Milk, an essential part of diet is comprised of all indispensable nutrients. However, it proves to be beneficial only if it is available in its pure form.

The current study aimed to evaluate packaged milk samples collected from local markets of Karachi and to assess level of consumer awareness about health risks associated with substandard milk consumption.

Package milk samples were assessed collectively for physical parameters, and microbial load. Seventeen colour-based chemical tests were also conducted to detect different dyes, preservatives, and other added chemicals as adulterants in milk. A household-based community survey was conducted to evaluate consumer’s preferences regarding packaged milk consumption.

97% of tested milk samples were observed to have added solids and water in them. Chemical adulterants in tetra packaged milk were detected in order of Glucose > cane sugar, Vegetable fat > Formalin, >Artificial colour > Neutralizer > Detergent >Urea, Annatto dye > starch. For the household-based survey, a total of 266 respondents were interviewed. Although 61.7% of respondents preferred pasteurized milk, potential customer satisfaction with the quality of pasteurized milk was 74.4%. Multivariate analysis showed that customer satisfaction regarding pasteurized milk was significantly associated with the preference of customer [Odds Ratio (OR)=4.18, p=0.004], buying factors like price, offers, and discounts (OR=6.92, p=0.014), quality and availability (OR=4.81, p=0.003), and experienced negative health effects (OR=0.26, p=0.002).

The study concluded that more than 70% of the packaged milk samples were adulterated with detergents, artificial flavors and glucose which signify the compromised quality of the packaged milk and their products. Strict regular quality checks should be established and closely monitored by regulatory authorities and the government.

In this study, aiming to solve the problem of difficult recovery of powder catalysts in the treatment of antibiotic wastewater by photocatalytic technology, titanium dioxide nanotubes (TiO2 NTs) photoelectrodes were prepared on titanium sheet substrates by anodic oxidation method.

The precious metals Pd and Ag were introduced to be co-deposited, which realized the effective transfer of photogenerated electrons between the semiconductor and the precious metals and remarkably improved the photoelectrocatalytic activity of the photoelectrodes.

The experimental results showed that the prepared Pd/Ag/TiO2 NTs composite photoelectrode achieved a removal efficiency of 79.51% for tylosin (TYL) within 240 min, which was significantly better than that of the pure TiO2 NTs (1.42-fold) and Ag/TiO2 NTs (1.05-fold) photoelectrodes. Electrochemical analyses demonstrated that the loading of Ag and Pd on the surface of TiO2 NTs can effectively promote the transport and separation of photogenerated charge carriers, thus improving the photoelectrocatalytic performance. In addition, the degradation process of TYL and the dynamic changes of intermediates were deeply analyzed with the help of three-dimensional fluorescence spectroscopy (3D EEMs) and two-dimensional correlation spectroscopy (2DCOS) techniques.

This study provides not only an expanded application of solid catalysts in photoelectrocatalytic treatment of antibiotic wastewater but also new insights for further investigation of the co-deposition of precious metals to improve photoelectrodes.

In this study, the contents of essential and non-essential elements in the sugary and sugar-free varieties of aromatic coffees produced in Turkey were decided, and the effect of sugar addition was examined.

For this purpose, essential (Mg, Se, B, Na, Ca, K, Co, Cr, Fe, Cu, Mn, Mo, P and Zn) and non-essential (As, Ba, Al, Cd, Ti, Ni, Sb and Pb) element contents of the aromatic coffees (sugary and sugar-free) (Classic, Gum Mastic, Gum Mastic Turkish Coffee, Hazelnut, Caramel and Turkish Coffee) supplied from a single brand were detected by using ICP-OES. The effects of the elements taken into the body by the consumption of coffee varieties on health and how much of an individual’s daily requirements are met were investigated. Thus, the place and importance of coffee consumption in nutrition have been determined. For coffee consumption of 3 cups, the intake amounts of selected elements were calculated. Furthermore, a risk assessment study was performed by utilizing the non-essential element concentrations of selected coffees.

Experimental results showed that K is the most ample essential element in all types of coffee, and it has been proven that K ingestion encounters the daily requirement of 1% to 2% for adults.

According to the risk assessment results, the hazard index was calculated for 3 cups of each coffee type intake as less than 1, and these coffees may be classified in the low-risk group.

Ubrogepant is a regulated peptide receptor antagonist associated with the calcitonin gene, granted approval in the United States for the specific treatment of migraine headaches.

An impurity found in the alkali hydrolysis of drug dosage forms has a structure very similar to that of ubrogepant. This research aims to characterize this analogous impurity utilizing NMR and LC-MS spectroscopy tools. Moreover, it is critical to develop an extremely sensitive and superior resolution analytical procedure for identifying and determining the amount of analogous impurity in pharmaceutical products.

The ubrogepant impurity was identified using an optimized chromatographic method that relies on reversed-phase HPLC with UV detection. This technique utilized a charged surface hybrid (CSH) technology column operating in gradient elution mode. A mixture of A-channel (0.1% trifluoroacetic acid) and B-channel (acetonitrile and water, 80:20% v/v) constituted the eluent. The analogous impurity was isolated through fraction collection, purified using flash chromatography, and characterized using NMR (1D and 2D) and LC-MS.

The analogous impurity was successfully separated from the ubrogepant peak with a resolution above 2.0. The concentration of the impurity was approximately 10% compared to the ubrogepant peak after alkaline stressing at room temperature for 30 minutes. NMR (1D 13C NMR and 1H, 2D HMBC, HSQC, NOESY, and COSY) and LC-MS analysis characterized the ubrogepant impurity, revealing it to be an epimer of ubrogepant. The developed approach was highly sensitive, allowing for the quantification of the ubrogepant impurity even at a concentration of 0.2 µg/mL.

The approach demonstrated a remarkable degree of precision, linearity, specificity, and accuracy. This new impurity deserves special attention because of its striking similarity to the active ingredient, ubrogepant.

PYX-201 is an Antibody-Drug Conjugate (ADC) composed of a fully human IgG1 antibody, a cleavable linker mcValCitPABC, and toxic auristatin payloads Aur0101, with a drug antibody ratio (DAR) of approximately 4. PYX-201 is a promising candidate for oncology treatment because it targets the extra domain B splice variant of fibronectin (EDB + FN), which is expressed at low levels in normal adult tissues while at moderate or high levels in various human solid tumors.

An electrochemiluminescence (ECL) immunoassay was developed and validated for the detection (screening, confirmatory, and titration) of antibodies to an ADC PYX-201 in human plasma. Anti-PYX-201 antibodies were captured by biotinylated PYX-201 (Bio-PYX-201) and detected by ruthenylated PYX-201 (Ru-PYX-201) on a Meso Sector imager S 600 or 6000 reader.

The screening cut-point factor (SCPF), confirmatory cut-point (CCP), and titration cut-point factor (TCPF) were found to be 1.11, 20.7%, and 1.23, respectively. Sensitivity was determined to be 2.25 ng/mL in the screening assay and 5.34 ng/mL in the confirmatory assay for anti-PYX-201 antibodies. Sensitivity was determined to be 7.70 ng/mL in the confirmatory assay for anti-PYX-201 monoclonal antibody (mAb) antibodies. The positive controls (PCs) were set at the following levels: low positive control (LPC) at 14.0 ng/mL, medium positive control (MPC) at 100 ng/mL, and high positive control (HPC) at 5,000 ng/mL. The drug tolerance was up to 200 µg/mL at the HPC level, up to 100 µg/mL at the MPC level, and 0 µg/mL at the LPC level. The intra-assay percent coefficient of variation (%CV) was ≤ 4.5% for PCs in the screening assay and ≤ 11.5% for PCs in the confirmatory assay. The inter-assay %CV was ≤ 13.6% for PCs in the screening assay and ≤ 19.2% for PCs in the confirmatory assay. No hook effect, hemolysis effect, or lipemia effect was found in this ADA method. Anti-PYX-201 antibodies were found stable in human plasma for at least 24 hours at room temperature or after six freeze/thaw cycles.

Anti-PYX-201 ADA bioanalytical method validation was reported for the first time in any biological matrix. This ADA method has been successfully applied to human sample analysis to support a clinical study.

Venetoclax is a selective inhibitor of the prosurvival protein BCL-2 approved by the Food Drug Administration in 2016, restoring the apoptic ability of malignant cells. In this study, a fast, highly accurate and precise HPLC method was developed for the analysis of Venetoclax in human plasma.

The optimization of the method was investigated according to Box-Bhenken Design combined with 3D surface methodology. The chromatographic separation was performed in gradient mode with an Ascentis Express C8 column (2.7 μm, 4.6 mm × 10 cm). Agomelatine was used as an internal standard to increase accuracy. The method was completely validated according to ICH guideline M10 bioanalytical method validation. Additionally, the greenness of the method was scaled with NEMI, Analytical Ecoscale, AGREE, and GAPI greenness metrics.

The method was linear in the range of 1.67-12.50 µg/mL with a calculated R² of 0.99; LOD and LOQ were 0.34 µg/mL and 1.02 µg/mL, respectively. The recovery was in the range of 102.6% to 99.08%, and with an RSD% of less than 1.00%. The analytical eco scale and AGREE score of the current method were 85 and 0.55, respectively.

The approach that was developed herein exhibits green, rapidity, high levels of accuracy and precision, cost-effectiveness, and ease of use in the context of clinical and pharmacokinetic investigations.