UHPLC-MS/MS method for simultaneous determination of carbamazepine and its seven major metabolites in serum of epileptic patients

Structural characteristics of sulfated xylogalactomannan isolated from Caulerpa okamurae and its anticoagulant activity

Due to wonderful taste, rich nutrition and biological functions, many marine green algae in the genus Caulerpa have been recently developed as candidates for green caviar. A novel water-soluble sulfated xylogalactomannan CO-0-1 was obtained from the green algae Caulerpa okamurae. CO-0-1 was mainly composed of mannose (Man), galactose (Gal), and xylose (Xyl) at the ratio of 4.4:4.0:1.4 with the molecular weight at 470 kDa and the sulfate content at 12.78 %. The sulfated xylogalactomannan had Man at the backbone with →4)-β-D-Manp-(1→ and →2)-β-D-Manp-(1→ as the main chain and branches at O-3 position. The side chains contained →3)-β-D-Galp-(1→ and minor →2)-β-D-Xylp(1→. The sulfate groups only distributed at the side chains and at O-6 position of →3)-β-D-Galp-(1→ and O-4 position of (1→2)-β-D-Xylp. The anticoagulant activity indicated that CO-0-1 displayed intrinsic anticoagulant and specific anti-thrombin activities. The investigation expanded the utilization and development scene and scope of the green algae Caulerpa okamurae.

Limitations of wastewater treatment plants in removing trace anthropogenic biomarkers and future directions: A review

This review highlights the limitations faced by conventional wastewater treatment plants (WWTPs) in effectively removing contaminants of emerging concern (CECs), heavy metals (HMs), and Escherichia coli (E. coli). This emphasises the limitations of current treatment methods and advocates for innovative approaches to enhance the removal efficiency. By following the PRISMA guidelines, the study systematically reviewed relevant literature on detecting and remedying these pollutants in wastewater treatment facilities. Conventional wastewater treatment plants struggle to eliminate CECs, HMs, and E. coli owing to their small size, persistence, and complex nature. The review suggests upgrading WWTPs with advanced tertiary processes to significantly improve contaminant removal. This calls for cost-effective treatment parameters and standardised assessment techniques to enhance the fate of MPs in WWTPs and WRRFs. It recommends integrating insights from mass-balance model studies on MPs in WWTP to overcome modelling challenges and ensure model reliability. In conclusion, this review underscores the urgent need for advancements in wastewater treatment processes to mitigate the environmental impact of trace anthropogenic biomarkers. Future efforts should focus on conducting comprehensive studies, implementing advanced treatment methods, and optimising management practices in WWTPs and WRRFs.

Serum Metabolomics Reveals Metabolomic Profile and Potential Biomarkers in Asthma

PURPOSE

Asthma is a highly heterogeneous disease. Metabolomics plays a pivotal role in the pathogenesis and development of asthma. The main aims of our study were to explore the underlying mechanism of asthma and to identify novel biomarkers through metabolomics approach.

METHODS

Serum samples from 102 asthmatic patients and 18 healthy controls were collected and analyzed using liquid chromatography-mass spectrometry/mass spectrometry (LC-MS/MS) system. Multivariate analysis and weighted gene co-expression network analysis (WGCNA) were performed to explore asthma-associated metabolomics profile and metabolites. The Kyoto Encyclopedia of Genes and Genomes (KEGG) was used for pathway enrichment analysis. Subsequently, 2 selected serum hub metabolites, myristoleic acid and dodecanoylcarnitine, were replicated in a validation cohort using ultra-high performance LC-MS/MS system (UHPLC-MS/MS).

RESULTS

Distinct metabolomics profile of asthma was revealed by multivariate analysis. Then, 116 overlapped asthma-associated metabolites between multivariate analysis and WGCNA, including 12 hub metabolites, were identified. Clinical features-associated hub metabolites were also identified by WGCNA. Among 116 asthma-associated metabolites, Sphingolipid metabolism and valine, leucine and isoleucine biosynthesis were revealed by KEGG analysis. Furthermore, serum myristoleic acid and dodecanoylcarnitine were significantly higher in asthmatic patients than in healthy controls in validation cohort. Additionally, serum myristoleic acid and dodecanoylcarnitine demonstrated high sensitivities and specificities in predicting asthma.

CONCLUSIONS

Collectively, asthmatic patients showed a unique serum metabolome. Sphingolipid metabolism and valine, leucine and isoleucine biosynthesis were involved in the pathogenesis of asthma. Furthermore, our results suggest the promising values of serum myristoleic acid and dodecanoylcarnitine for asthma diagnosis in adults.

Single-crystal vs polycrystalline boron-doped diamond anodes: Comparing degradation efficiencies of carbamazepine in electrochemical water treatment

The ongoing challenge of water pollution by contaminants of emerging concern calls for more effective wastewater treatment to prevent harmful side effects to the environment and human health. To this end, this study explored for the first time the implementation of single-crystal boron-doped diamond (BDD) anodes in electrochemical wastewater treatment, which stand out from the conventional polycrystalline BDD morphologies widely reported in the literature. The single-crystal BDD presented a pure diamond (sp3) content, whereas the three other investigated polycrystalline BDD electrodes displayed various properties in terms of boron doping, sp3/sp2 content, microstructure, and roughness. The effects of other process conditions, such as applied current density and anolyte concentration, were simultaneously investigated using carbamazepine (CBZ) as a representative target pollutant. The Taguchi method was applied to elucidate the optimal operating conditions that maximised either (i) the CBZ degradation rate constant (enhanced through hydroxyl radicals (•OH)) or (ii) the proportion of sulfate radicals (SO4•-) with respect to •OH. The results showed that the single-crystal BDD significantly promoted •OH formation but also that the interactions between boron doping, current density and anolyte concentration determined the underlying degradation mechanisms. Therefore, this study demonstrated that characterising the BDD material and understanding its interactions with other process operating conditions prior to degradation experiments is a crucial step to attain the optimisation of any wastewater treatment application.

Differentiation of isomeric metabolites of carbamazepine based on acid-base properties; Experimental vs theoretical approach

Metabolism of carbamazepine is complex and leads to the three isomeric derivatives whose occurrence is dependent on the type of sample material. Their unambiguous differentiation is overall important. In this work, the qualitative analysis of 2-hydroxycarbamazepine, 3-hydroxycrbamazepine and carbamazepine-10,11-epoxide was attempted for the first time using capillary zone electrophoresis, based on the models linking electrophoretic mobility with pK_a value determining the acidity of the hydroxyl groups. For this purpose, pK_a values ​​were determined using electrophoretic and theoretical methods, and then the compliance of the obtained mobility models with the measured values ​​was analyzed. Despite the slight difference in acidity ​​(0.3-0.4 pH unit), the obtained results prove that the correct identification of the metabolites under consideration, and reliable prediction of the selectivity of their separation, are possible on the basis of experimentally determined pK_a values, even with highly simplified methods assuming the lack of certain data. However, it is important to choose the optimal pH value, which should be close to pK_a. On the other hand, worse results were obtained for the theoretically determined mobilities, which differed significantly from the experimental values. An attempt was also made to explain the acidity of hydroxycarbamazepines and the associated thermodynamic parameters - deprotonation enthalpy and entropy, with respect to their structure. The lack of intramolecular hydrogen bonds and the significant contribution of entropic effects stabilizing the protonated form seems to be significant. The higher pK_a value for CBZ-2-OH probably results from the stronger effect of the energetically unfavorable organization of solvent dipoles due to ionization.

New Methods Used in Pharmacokinetics and Therapeutic Monitoring of the First and Newer Generations of Antiepileptic Drugs (AEDs)

The review presents data from the last few years on bioanalytical methods used in therapeutic drug monitoring (TDM) of the 1st-3rd generation and the newest antiepileptic drug (AEDs) cenobamate in patients with various forms of seizures. Chemical classification, structure, mechanism of action, pharmacokinetic data and therapeutic ranges for total and free fractions and interactions were collected. The primary data on bioanalytical methods for AEDs determination included biological matrices, sample preparation, dried blood spot (DBS) analysis, column resolution, detection method, validation parameters, and clinical utility. In conclusion, the most frequently described method used in AED analysis is the LC-based technique (HPLC, UHPLC, USLC) combined with highly sensitive mass detection or fluorescence detection. However, less sensitive UV is also used. Capillary electrophoresis and gas chromatography have been rarely applied. Besides the precipitation of proteins or LLE, an automatic SPE is often a sample preparation method. Derivatization was also indicated to improve sensitivity and automate the analysis. The usefulness of the methods for TDM was also highlighted.

Occurrence of the main metabolites of pharmaceuticals and personal care products in sludge stabilization treatments

In Europe, approximately 40% of sludge yearly produced in wastewater treatment plants (WWTPs) is applied in agricultural lands as organic amendment, especially in arid regions. Sludge tends to concentrate wastewater pollutants. Many of them are not removed by sludge stabilization treatments and, as a result, they could originate adverse effects on soils, vegetation, animals, and humans. Although sludge stabilization treatments play an important role in removal contaminants from sludge and, therefore, in preventing contaminant discharges onto soils, there is scarce information about the occurrence of these compounds in these treatments. This fact is especially acute for emerging pollutants and, particularly, their metabolites. In this work, seven pharmaceuticals and personal care products, and their main metabolites, have been monitored in five different stabilization treatments: anaerobic and aerobic digestion, dehydration, composting, and lagooning. Sixteen compounds were measured in the analysed samples. Their distribution was similar in primary sludge, in spite of the different geographic locations of the WWTPs, The distribution was in accordance with the metabolic ratios of most of the studied compounds. Different behaviour was observed depending on the compound, for example, CBZ, 3-OH-CBZ, DIC, and 4-OH-DIC were highly persistent in all studied stabilization technologies whereas CAF, PX showed high degradability. Most of the studied compounds were measured in the final product of the sludge stabilization processes evaluated. This fact shows the necessity to improve the knowledge about the presence of these compounds in sludge intended to be applied onto soil and about the potential ecotoxicological risks of these compounds.

Ozonation of carbamazepine and its main transformation products: product determination and reaction mechanisms

Carbamazepine (CBZ) is a recalcitrant pharmaceutical often detected in wastewater and in the environment. CBZ can be removed from wastewater through advanced oxidation treatment methods such as ozonation. In this study, CBZ and its transformation product 1-(2-benzaldehyde)-(1H,3H)-quinazoline-2,4-dione (BQD) were ozonated, and the formation and transformation of their ozonation products were investigated using liquid chromatography coupled to ion trap mass spectrometry and high-resolution mass spectrometry as well as nuclear magnetic resonance (NMR). The main products, 1-(2-benzaldehyde)-4-hydro-(1H,3H)-quinazoline-2-one (BQM) and BQD were quantified using isolated standards and LC-UV. Of the original CBZ concentration, 74% was transformed into BQM and 83% of BQM was further transformed into BQD. Both products are more stable than CBZ and could still be detected after 240 min of ozonation. Another major product, 2,2'-azanediyldibenzaldehyde (TP225) was for the first time identified using NMR. Twelve further CBZ products were identified.