High-performance Liquid Chromatography Research Articles

Nutritional, phytochemical, and antimicrobial properties of Senna siamea leaves

Senna siamea is a medicinal plant with numerous benefits in different parts of the world. This study evaluated the leaf's nutritional composition, mineral composition, phytochemical constituents, antioxidant properties and antimicrobial properties, and high-performance liquid chromatography (HPLC) using standard methods. The proximate analysis revealed the presence of moisture content (12.14 ± 0.01), ash content (1.05 ± 0.07), crude fat (4.21 ± 0.10), crude protein at (9.78 ± 0.11), crude fiber (2.70 ± 0.32), and carbohydrate content (70.12 ± 0.37). Mineral analysis showed an abundance of potassium (125.18 ± 0.04), followed by magnesium (32.62 ± 0.01), and phosphorus (18.30 ± 0.02). The phytochemical screening revealed the presence of saponins, flavonoids, phenolics, steroids, and alkaloids with 13.25 ± 0.03 mg GAE/g total phenolics and 3.99 ± 0.01 mg QE/g flavonoid contents, respectively. IC50 values of the scavenging abilities of DPPH, NO radicals, and TBARS were 206.01 µg/mL, 347.66 µg/mL, and 394.92 µg/mL, respectively while the IC50 value for FRAP was 145.01 µg/mL. Salmonella typhimurium 14028 and Pseudomonas aeruginosa 27853 were most susceptible. At 100 mg/mL, their average zone of inhibition was 18 and 16 mm for ethyl acetate and 15 and 12 mm for methanol, respectively. The minimum inhibitory concentration (MIC) for both isolates was 25 and 50 mg/mL while the leaves were rich in chlorogenic acid, p-coumaric acid, friedelin, quercetin, emodin, cassiarin A, and kaempferol. These results reveal the leaf as a good source of nutrients and also confirm its phenolic antioxidant activity and antimicrobial properties.

Impact of zinc oxide nanoparticles on biosynthesis of thymoquinone in cell cultures of Nigella sativa

The rising market interest for Nigella sativa (Black seeds) necessitates the development of cultivation strategies to enhance metabolites production. Zinc oxide nanoparticles (ZnO-NPs) have drawn global attention as efficient and bio safe elicitors for in vitro cultures, to enhance secondary metabolites production in medicinal plants. In this study, ZnO-NPs were utilized for establishment of callus and cell cultures in black seeds for the first time. Hypocotyl explants were cultured on Murashige and Skoog (MS) media with varying levels of ZnO-NPs, resulted in callus induction and biomass formation. Optimal response in callus growth parameters were observed when explants were grown on MS media supplemented with 60 mg/L ZnO-NPs, resulting in 71.2 % callus induction frequency, 28.2 g/L fresh biomass, 9.7 g/L dry biomass, and 63 % water content. A substantial increase in callus growth was observed when ZnO-NPs were combined with 6-Benzylaminopurine (BA) at ratio of 45:1.5 mg/L, resulting in 91.2 % callus induction frequency and 42.2 g/L fresh biomass. In cell suspension cultures, ZnO-NPs alone at 45 mg/L produced optimum callus biomass (60.9 g/L). However, in combination with BA, callus biomass did not increase significantly in cell cultures. Maximum accumulation of total phenolic content (TPC: 26.8 mg GAE/g DW; Gallic acid equivalent dry weight) and total flavonoid content (TFC: 19.5 mg QE/g DW; Quercetin equivalent dry weight) was observed in cell cultures treated with higher concentration (70 mg/L) of ZnO-NPs in the 5th week of the growth curve. Moreover, ZnO-NPs incremented substantially the Phenylalanine lyase (PAL), Superoxide dismutase (SOD) and Peroxidase (POD) enzyme activities in cell cultures. Nonetheless, Reverse Phase High Performance Liquid Chromatography (RP-HPLC) analysis indicated peak production of thymoquinone (168.5 mg/g FW) in cell cultures treated with 45 mg/L ZnO-NPs alone. This study offers a promising approach for commercial production of Nigella sativa biomass and bioactive metabolites.

Synthesis and Characterization of Asymmetric Azatwistarenes with Chiroptical Property.

Three novel azatwistarenes 5a, 8, and 13 have been synthesized via the Povarov reaction and fully characterized. All of the enantiomers were separated using chiral high-performance liquid chromatography, and their optical properties were investigated through circular dichroism and circularly polarized luminescence spectra. In addition, such desired azatwistarenes have a positive response to acid in dichloromethane.

Study on HPLC fingerprint of Saposhnikovia divaricata lipophilic components and anti-aging effects

Saposhnikovia divaricata is commonly used in clinical practice as a heat-clearing and detoxifying traditional Chinese medicine. Current research on Saposhnikovia divaricata has mostly focused on chromones, while studies on its lipophilic parts remain scarce. In this study, samples of the lipophilic components of Saposhnikovia divaricata (SDL) from different regions in China were collected to establish an HPLC fingerprint. The quality of SDL was evaluated through chemical pattern recognition and multi-component content determination. Furthermore, using the Caenorhabditis elegans (C. elegans) model, the anti-aging ability of SDL was preliminarily studied. In the HPLC fingerprints of 11 batches of SDL, 19 common peaks were identified, and 4 components were characterized as follows: peak 14, linolenic acid (ALA); peak 15, docosahexaenoic acid (DHA); peak 16, linoleic acid (LA); peak 17, oleic acid (OA). The similarity of the fingerprint ranged from 0.704 to 0.929. The results indicate that the content of ALA, DHA, LA, and OA are 0.040–0.440 mg/g, 0.003–0.116 mg/g, 1.047–6.460 mg/g, and 0.040–0.294 mg/g, respectively. HCA analysis divided 11 batches of SDL into two categories, and PCA analysis extracted 6 principal components with a cumulative contribution rate of 85.91%. The anti-aging ability of the SDL was proved by measuring the lifespan, reproductive capacity, body length, mobility, lipofuscin content, and heat stress resistance of C. elegans. The combination of high-performance liquid chromatography fingerprint and chemical pattern recognition for multi-component content determination is a reliable, comprehensive, and promising evaluation of the quality of SDL. The confirmation of SDL’s anti-aging ability provides the possibility for the research of Saposhnikovia divaricata in the field of healthy food and cosmetics.

A Pharmacokinetic Study of the Interaction Between Regorafenib and Paracetamol in Male Rats

Background: In clinical practice, the prevalent problem of polypharmacy could result in increased risks of drug–drug interactions. Regorafenib (REG) is commonly co-administered with paracetamol (PA) as a treatment protocol in cancer patients with pain therapy. Purpose: This study aimed to demonstrate the effect of paracetamol on the pharmacokinetic parameters of regorafenib and its metabolites following a single administration of both substances in rats. Additionally, the influence of REG and its metabolites on the pharmacokinetics of paracetamol was also determined. Methods: Twenty-four rats were divided randomly into three groups: REG group (IIREG, regorafenib 20 mg/kg, n = 8), PA group (IIIPA, paracetamol 100 mg/kg, n = 8), and REG+PA co-administration group (IREG+PA, REG 20 mg/kg and PA 100 mg/kg, n = 8). The concentrations of regorafenib, regorafenib-N-oxide (M-2), and N-desmethyl-regorafenib-N-oxide (M-5) were determined using ultra-performance liquid chromatography-tandem mass spectrometry (UPLC–MS/MS). The plasma concentrations of PA and its glucuronide (GPA) and sulfate (SPA) metabolites were measured using the validated high-performance liquid chromatography method with ultraviolet detection (HPLC–UV). The pharmacokinetic parameters were calculated using a non-compartmental model. The statistical evaluation was performed in the SAS program. Results: After the administration of PA, the Cmax and AUC0–∞ of REG increased by 890% and 1140%, respectively; for M-2, they increased by 220% and 170%, and for M-5, by 2130% and 1730% (Cmax and AUC0–∞, respectively). A difference in the ratio of M-2/REG for AUC0–∞ and Cmax between the groups was observed, but not for M-5/REG. The AUC0–∞ for PA and GPA decreased by 20.7% and 51.1%, respectively, when PA was co-administered with REG. But the AUC0–∞ for SPA increased by 91.35% in the IREG+PA group. A difference in the ratio of GPA/PA for Cmax and for SPA/PA for AUC0–t and AUC0–∞ between the groups was observed. Conclusions: Paracetamol increased the plasma exposure of regorafenib, M-2, and M-5, which may exacerbate the drug’s side effects. In contrast, REG reduced paracetamol exposure and contributed to its faster elimination, which may reduce the analgesic and antipyretic effects of paracetamol. These findings suggest clinical relevance for oncology patients requiring analgesic treatment.

Antioxidant and Anti-Inflammatory Properties of Conceivable Compounds from Glehnia littoralis Leaf Extract on RAW264.7 Cells.

Glehnia littoralis is a medicinal plant, but the scientific basis is still unclear. This study thoroughly investigated phenols from Glehnia littoralis extract (GLE) to determine their potential as anti-inflammatory and antioxidant agents. High-performance liquid chromatography (HPLC) and mass spectrometry (MS) were used to analyze the compounds in GLE. In addition, we performed GLE in vitro in macrophages after lipopolysaccharide (LPS)-induced inflammation. The extract contained eight peaks representing phenolic compounds and one peak representing riboflavin, with the corresponding mass spectrometry data documented. These biologically active compounds were purified by ultrafiltration using LC to determine their ability to target cyclooxygenase-2 (COX-2) and 2,2-diphenyl-1-picrylhydrazyl (DPPH). The results showed that significant compounds were identified, demonstrating a binding affinity for both COX-2 and DPPH. This suggests that the compounds showing excellent binding affinity for COX-2 and DPPH may be the main active ingredients. Vital inflammatory cytokines, including COX-2, inducible nitric oxide synthase (iNOS), mitogen-activated protein kinase (MAPK), and nuclear factor kappa B (NF-κB), were found to be down-regulated during the treatment. In addition, we revealed that the selected drugs exhibited potent binding capacity to inflammatory factors through molecular docking studies. In addition, we confirmed the presence of phenolic components in GLE extract and verified their possible anti-inflammatory and antioxidant properties. This study provided evidence for an efficient strategy to identify critical active ingredients from various medicinal plants. These data may serve as a baseline for further investigations of applying GLE in the pharmaceutical industry.

Unveiling the chemical composition, antioxidant and antibacterial properties, and mechanistic insights of Convolvulus arvensis extract through molecular docking simulations

The use of herbal extracts has gained significant importance in modern health practices, making it essential to explore their properties and applications in detail. This study investigates the effect of ultrasound on the extraction yield of Convolvulus arvensis leaves, with a focus on its chemical composition, antioxidant properties, cytotoxicity, antimicrobial activities, and mechanism of action. Antimicrobial activity was determined using minimum inhibitory concentration (MIC), minimum bactericidal concentration (MBC), well diffusion agar, and disk diffusion agar assays. The antioxidant properties were assessed through ferric reducing antioxidant power (FRAP) and DPPH free radical scavenging assays. High Performance Liquid Chromatography (HPLC) and Fourier transform infrared (FTIR) spectroscopy were utilized to identify the chemical composition and functional groups present in the extract. The findings revealed that ultrasound-assisted extraction exhibited significantly higher extraction efficiency (p < 0.05). The extract displayed significant antimicrobial activity against Listeria innocua, Pseudomonas aeruginosa, Escherichia coli, and Staphylococcus aureus. The total phenolic and total flavonoid contents of the extract were measured at 328.85 ± 0.046 (mg GAE/100 g) and 226.23 ± 0.043 (mg QE/100 g), respectively. Moreover, the extract demonstrated notable radical scavenging activity against DPPH, with a value of 37.40 ± 0.111 (g/100 g). The FRAP assay revealed that the antioxidant activity of C. arvensis extract was quantified at 23.796 ± 0.045 μmol Fe²⁺. The highest amount of phenolic and alkaloid compounds in the extract was related to β-Phellandrene (341.52 µg/mL) and Swainsonine (360.24 µg/mL), respectively. Furthermore, the in vitro cytotoxic activity of the extract was evaluated against the Caco-2 cell line, with the IC50 value determined to be 26.55 mg/mL. The results of the docking study demonstrated that Ferulic acid displayed a significant binding energy of −6.2 kcal/mol, suggesting a robust interaction with the target enzyme and the potential to act as a modulator of glutathione peroxidases. The findings of the present study revealed that the alcoholic extract of C. arvensis possesses proper antioxidant and antimicrobial activities. Therefore, it has been used as a food preservative. However, further medical and clinical researches are required before any application in human health.

Contribution of haptoglobin phenotypic variation to the presence of hyperhomocysteinemia in type 2 diabetics with and without angiopathy.

The genetic polymorphism of haptoglobin (Hp) has been associated with several cardiovascular risk factors, but a possible relationship between Hp phenotypic variation and increased levels of homocysteine (Hcy) and cysteine (Cy) is still unknown. The objective of this study is to evaluate the relationship between the Hp polymorphism and hyperhomocysteinemia (HHcy) and hypercysteinemia (HCy) in type 2 diabetics (T2D) with and without angiopathy (AGP). A case-control study was carried out on 293 adults: Group I (GI) - 75 subjects with T2D and AGP; Group II (GII) - 75 subjects with T2D without AGP; Group III (GIII) - 143 controls. Plasma levels of Hcy, Cy and vitamin B6 were measured by high performance liquid chromatography (HPLC) and vitamins B9 and B12 determined by electrochemiluminescence (ECL). The Hp polymorphism was identified by sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) and peroxidase staining. The results were analyzed in SPSS®, version 26.0 with a significance of 95%. Mean Hcy concentrations were significantly lower in carriers of the Hp2-2 phenotype (6.14 µM; p = 0.046) compared to the other genotypes. The presence of Hp2-1 is associated with an approximately 3.3 times greater probability of occurrence of HHcy (p = 0.015) and 3.7 times greater probability occurrence of HCy (p = 0.021) in T2D with AGP. The presence of the Hp2-1 phenotype is associated with the predisposition of HHcy and HCy in individuals with T2D and AGP, possibly through a positive heterosis mechanism. Carriers of the Hp2-2 phenotype appear to have a greater activation of the transsulfuration pathway in the Hcy cycle and consequent protection for its accumulation.

Determining the Pharmacokinetic Properties of Two Different Doses of Meloxicam in Barred Owls (Strix varia).

Anthropogenic activities have negatively affected many birds, including owls. The Wildlife Hospital of Louisiana (WHL) has seen a 3.2-fold increase in barred owl (Strix varia) cases over the past eight years (2023, 134; 2015, 42). Because most of these animals present with traumatic injuries, analgesics should be considered in their treatment plan. To date, no study has measured the pharmacokinetics of an analgesic in barred owls. The goals of this study were to determine the harmonic means, times to maximum concentration, and elimination half-lives for single 1 mg/kg and 2 mg/kg intramuscular doses of meloxicam. Twelve barred owls (1 mg/kg, n = 6; 2 mg/kg, n = 6) admitted to the WHL and determined to be clinically normal based on examination and blood work were recruited for this study. Meloxicam was administered intramuscularly, and blood samples were collected intermittently over 12 h to measure plasma concentrations using high-performance liquid chromatography. Both doses had rapid elimination half-lives (1 mg/kg, 0.99 ± 0.1 h; 2 mg/kg, 1.07 ± 0.43 h) and were below the limits of quantification (0.1 µg/mL) by 6-12 h. Based on these results, 1 and 2 mg/kg doses of meloxicam were found to produce plasma concentrations below therapeutic concentrations for less than four hours, making current twice-daily recommended dosing intervals unlikely to provide desired analgesia.

Determination of PAH Contamination in Breast Milk Samples from Hungarian Volunteering Mothers, Using HPLC-FLD.

(1) The evidence is mounting that polycyclic aromatic hydrocarbons (PAHs) are a class of hazardous organic compounds with established carcinogenic and toxic properties. Humans may be exposed to PAHs through several different routes, including diet, inhalation, and dermal contact. There is also a possibility that they could transfer into breast milk following maternal exposure, which could potentially endanger breastfeeding infants. (2) The objective of this study was to ascertain the concentration of polycyclic aromatic hydrocarbons (PAHs) in breast milk samples from 50 Hungarian mothers, employing high-performance liquid chromatography with fluorescence detection (HPLC-FLD). An Incremental Life Risk Calculation (IRCL) model estimated the carcinogenic risk to infants. (3) Total PAH concentrations ranged from 0 to 78 ng/mL, with fluorene (5.3 ng/mL), phenanthrene (3.2 ng/mL), and pyrene (2.5 ng/mL) being the most abundant. PAHs were detected in 48 of the 50 samples, with phenanthrene present in 92% of samples. Dibenzo (a,h)anthracene was not detected. (4) According to the model measurements, most of the samples were within acceptable risk levels; however, 2 samples out of 50 posed a higher risk. Statistical analysis of questionnaires completed by the mothers indicated that factors such as diet, residence, and education may influence PAH levels in breast milk.

Fabrication of a molecularly imprinted poly(methyl methacrylate) decorated graphite electrode for detection of aloe emodin in Aloe vera

In this work, the authors represent a comprehensive approach for the development and validation of a novel graphite-supported molecularly imprinted poly(methyl methacrylate) electrode for the selective and sensitive detection of aloe emodin (AE) in aloe-based cosmetic products. The electrocatalytic activity of the electrode was evaluated using cyclic voltammetry and differential pulse voltammetry techniques in phosphate buffer saline. Surface morphology, structural characteristics, and imprinting endorsement were investigated using field emission scanning electron microscopy, Fourier-transform infrared spectroscopy, and UV-Vis spectroscopy. Under the optimal conditions, the electrode showed an oxidative differential pulse voltammetry peak at -0.2931±0.011 V (vs. Ag/AgCl, saturated KCl). The current was increased linearly with increasing concentrations of AE from 0.0005 to 350 µM, with a low detection limit of 0.0003 µM. The voltammetric analysis has been validated by reverse-phase high-performance liquid chromatography (RP-HPLC) methods. A partial least square regression model was developed to correlate the results obtained from the proposed system with the reference values obtained by RP-HPLC. The model showed a high prediction accuracy of 95.95 % for the detection of AE in cosmetic samples. The developed electrode provides a low-cost, rapid, easy, and convenient method for the detection of AE in cosmetic products, offering potential benefits for quality control and safety assessment in the cosmetic industry.

Analysis and quantification of selected heavy metals and paraphenylenediamine in commercially available herbal black hair dyes in Sri Lanka

Currently, the use of henna-based herbal black hair dyes is widespread in the community. However, it is important to note that these dyes cannot be classified as completely natural due to the addition of various ingredients to enhance their effectiveness. Most black hair dyes use paraphenylenediamine (PPD) to get a black hue, however, PPD is widely recognized as a contact sensitizer. The toxicity of heavy metals is also prevalent in the cosmetics sector. These metallic elements can permeate the skin and provide widespread exposure throughout the body. Hair dye requires an alkaline pH value because of reactions that occur during the dyeing process, which is incompatible with scalp pH. The varying concentrations of these chemicals and their frequency of usage can result in diverse health issues. The present research implemented High-Performance Liquid Chromatography and Atomic Absorption Spectrometry to quantify the concentrations of PPD and heavy metals (Pb, Cd, and Fe) in seven frequently used brands in Sri Lanka. The lead content in the examined samples exhibited variability, ranging from 0.04 ± 0.01 ppm to 0.28 ± 0.14 ppm. However, all the samples remained below the allowed level of 2 ppm according to the BVL standard. Regarding Cd, certain examined materials surpassed the acceptable thresholds, while others did not and varied between 0 ppm and 2.33 ± 1.92 ppm. Iron was found at a significantly higher concentration compared to the other two heavy metals. A significant quantity of PPD was detected, exceeding the allowable threshold of 6 % according to the European Union legislation. All the samples that were analyzed had a pH value within the alkaline range. The study indicates that herbal dyes generated from natural materials may contain harmful compounds, such as a high concentration of PPD in herbal black hair color potentially inducing sensitization.

Assessment of miligram(Mg) content of some notable analgesics used by residents of Maiduguri Metropolis: evidence from high performance liquid chromatographic technique

Diclofenac sodium and paracetamol are Over the counter (OTC) medications used as analgesic and antipyretic agents to relieve pains, fever and headaches. The aim of this work was determine the mg content of paracetamol and diclofenac sodium in selected samples across the Maiduguri metropolis using High Performance liquid chromatography (HPLC) method. For paracetamol samples an intersil ODS-3V column (150 mm × 4.6 mm; 5 μm pore size) was used at the temperature of 35oC the mobile phase was methanol: water (20:80) using isocratic elution at the flow rate of 2 mL/min, injection volume of 10 μL and a diode array detector. For diclofenac sodium samples, the chromatographic conditions were the same except the mobile phase which was methanol: water (63:37), flow rate of 0.8 mL min, injection volume of 20 μL and column temperature was set at 30 oC. A total of 45 samples were analysed; which comprised of paracetamol tablet, paracetamol syrup and diclofenac sodium tablet which were randomly selected from three different sources; hospital pharmacy, community pharmacy and drug patent stores. The percentage mg content for paracetamol tablets ranged from 48 to 83 % while that of the paracetamol syrups ranged from 72 to 120 % and finally diclofenac sodium tablets ranged from 73 to 174 %. Adopting the United State Pharmacopoeia (USP) as reference for assessment tool, it was observed that all the paracetamol tablet samples failed, 4 out of 15 paracetamol syrup samples failed, and 11 out of 15 diclofenac sodium tablet samples failed. There was statistical significance (p&lt; 0.05) between class of drug and percentage mg content but there was no significance (p&lt; 0.05) between source of drug and percentage constituent. HPLC technique was used successfully for quantitative determination of paracetamol and diclofenac sodium dosage forms.

Exposure to aflatoxins and ochratoxin A from the consumption of selected staples and fresh cow milk in the wet and dry seasons in Ghana

Across sub-Saharan Africa, the heavy reliance on mycotoxin-susceptible staple foods means that populations in the region are particularly vulnerable to chronic mycotoxin exposure. This study assessed the exposure risk to ochratoxin A (OTA) and aflatoxins (AFs) from 18 samples of selected staple foods (maize, millet, groundnut) and 56 fresh cow milk samples collected from across Ghana. The foods were sampled simultaneously to maximise comparability, and at two timepoints in March/April (during the dry season) and July/August (during the rainy season) to assess the effects of duration of storage and seasonal conditions on the mycotoxin levels as measured by high-performance liquid chromatography. The margin of exposure (MOE) approach was used to assess the exposure risk from consumption of the sampled foods. Each of the sampled staples was contaminated with OTA (0.19–3.11 ng/g) and at least one AF (0.75–13.05 ng/g B1, ND-12.12 ng/g B2, 0.1–9.95 ng/g G1, ND-16.78 ng/g G2). Up to 67% had contamination above European Food Safety Authority (EFSA) maximum limits, and 50% were above Ghana Standards Authority (GSA) limits. The fresh cow milk samples were contaminated with AFM1 in the range of 0.05–1.49 ng/g, with 95% above EFSA limits and 36% above GSA limits. Aflatoxin contamination in the staples was high, particularly in July/August when the wet conditions may have adversely impacted the handling and storage of farm produce. Variation in AFM1 between the two sampling periods mirrored total aflatoxin in the staples, suggesting that even if dairy cattle were grazing in open pasture and not being rationed on stored feed, then there was a high environmental presence of aflatoxigenic fungi. The MOE estimates were ≤533.09, far below the safe cut-off of 10,000 for suspected carcinogenic compounds. The high mycotoxin levels indicate a priority risk to child nutrition which relies heavily on cereal mixes based on one or all the three sampled staples. The data from this study underscore the urgent need for interventions to better appreciate and address mycotoxin exposure for enhanced food security and public health in Ghana and across sub-Saharan Africa.

Ambient Air-Synthesized CsPbBr3 Nanocrystals Coupled with TiO2 Film as an Efficient Hybrid Photoanode for Photoelectrochemical Methanol-to-Formaldehyde Conversion.

Due to its exceptional optoelectronic properties in the visible spectrum, cesium lead bromide (CsPbBr3) perovskite has attracted considerable attention in solar-driven organic transformations via photoelectrochemical (PEC) cells. However, the performance of the devices is adversely affected by electron-hole recombination occurring between a transparent conductive substrate, such as fluorine-doped tin dioxide (FTO), and a perovskite layer. Herein, to mitigate this issue, a compact layer of titanium dioxide (TiO2) was employed as both an electron transport layer and a hole blocking layer to diminish charge recombination while facilitating electron transfer in such perovskite material. At the oxidation peak potential of 0.70 V vs Ag/AgNO3, a hybrid photoanode of CsPbBr3/TiO2/FTO exhibited a significant increase in photocurrent density, from 15 to 41 μA/cm2, compared to a configuration without a TiO2 layer. Furthermore, the introduction of methanol as a hole scavenger in the PEC system using the hybrid photoanode facilitated the separation of electron-hole pairs, which led to an enhanced photocurrent density of 60 μA/cm2 and promoted the production of formaldehyde. High-performance liquid chromatography (HPLC) confirmed the generation of formaldehyde at a concentration of 26.69 μM with a Faradaic efficiency of 92% under an applied potential of 0.50 V vs Ag/AgNO3 for 60 min of PEC reaction. In addition to the enhanced PEC performance achieved from this hybrid photoanode, CsPbBr3 nanocrystals (NCs) in this work were synthesized by the modified one-pot method under ambient air, where highly uniform and high-purity NCs were obtained. This work signifies the groundbreaking exploration of CsPbBr3 NCs with TiO2 as a photoelectrode material in the organic-based PEC cells, which efficiently improved the interfacial charge transfer within the photoanode for the conversion of methanol to formaldehyde, marking a significant advancement in the field.

Structural Characterization and Antioxidant Activity of Exopolysaccharide Produced from Beet Waste Residue by Leuconostoc pseudomesenteroides

Lactic acid bacteria exopolysaccharide (EPS) is a large molecular polymer produced during the growth and metabolism of lactic acid bacteria. EPS has multiple biological functions and is widely used in fields such as food and medicine. However, the low yield and high production cost of EPS derived from lactic acid bacteria limit its widespread application. In this study, we used beet waste residue as a substrate to produce EPS by fermentation with Leuconostoc pseudomesenteroides to improve the utilization rate of agricultural waste and reduce the production cost of lactic acid bacterial EPS. After purification, the molecular weight (Mw) of EPS was determined to be 417 kDa using high-performance size exclusion chromatography (HPSEC). High-performance liquid chromatography (HPLC), Fourier transform infrared (FTIR) spectroscopy, and nuclear magnetic resonance (NMR) spectroscopy revealed that the EPS was composed of glucose subunits with α-1,6 glycosidic linkages. The thermal analysis and heavy metal adsorption capacity revealed a relatively high degradation temperature of 315.54 °C and that the material could effectively adsorb Cu2+. Additionally, the findings indicated that the EPS exhibited a significant ability to neutralize free radicals, a property that was found to be concentration dependent. Furthermore, the results of the intracellular study showed the protective effect of freshly isolated EPS on tBHP-induced cellular oxidative stress at a concentration of 50 µg/mL. These results suggest that the EPS from L. pseudomesenteroides may be developed as antioxidant agents for functional food products and pharmaceutical applications due to its capacity to scavenge free radicals.

Drug Use during Incarceration: A Comprehensive Quality and Prevalence Study in Three Danish Prisons

Background Drug use in Danish prisons has previously not been investigated in detail using confirmatory, laboratory analysis. The objective of the present quality study, initiated by the Danish Prison and Probation Service, was to i) evaluate the performance of an initial, on-site drug screening strategy; ii) gain insights into emerging drug trends; and iii) suggest evidence-based strategies for future drug testing. Methods Over a two-year period, routine urine samples (n = 1952 from 710 inmates) from three Danish prisons were subjected to comprehensive drug testing. Immunoassay screening was conducted on-site. A parallel sample aliquot was forwarded to laboratory analysis by confirmatory methods: High-performance liquid chromatography and tandem mass spectrometry (LC-MS/MS) and gas chromatography and mass spectrometry (GC-MS) targeting 56 drugs-of-abuse/medical drugs, 26 key metabolites, 41 new psychoactive substances (NPS), including specific biomarkers for heroin, crack cocaine, or ethanol (a total of 123 target analytes/sample). Results The on-site immunoassay method showed a sensitivity from 66 to 100%; specificity was above 98%; accuracy was above 95%. Laboratory analysis detected compounds not screened for including tramadol, oxycodone, buprenorphine, ketamine, MDMA, 4-fluoroamphetamine, and GHB. The prevalence of drug use was in the order: cannabis > ethanol > cocaine > benzodiazepines > amphetamine. Conclusion The performance of the immunoassay was found acceptable; however, the screening program was inadequate for detecting other significant substances. Based on these findings, a broader screening method will be implemented in future at Danish Prisons to minimize false negative results. The data did not indicate a trend of using NPS in Danish prisons.

Determination of 3-hydroxyanthranilic acid in the sweat of healthy older adults

3-Hydroxyanthranillic acid (3HAA) is one of the key metabolites from the tryptophan (TRP) metabolism pathway and is associated with aging, age-associated diseases, and healthy lifespan extension. This study aims to detect 3HAA in the sweat of healthy older adults using simple, high-performance liquid chromatography (HPLC) method. Chromatographic separation using 20 mmol/L sodium acetate, 3 mmol/L zinc acetate, and 7% (v/v) acetonitrile as mobile phase is possible to simultaneous detect 3HAA, KYN, and TRP with UV and fluorescence detection, respectively, under 6 min. This method demonstrated excellent linearity with coefficient of determination (r2) greater than 0.998 for all analytes. The linear range were 0.05–6 µg/mL for TRP, 0.1–6 µg/mL for KYN and 0.2–6 µg/mL for 3HAA. Percentage recoveries from spiked in human sweat ranged from 90 ± 7–101 ± 3 for TRP, 86 ± 1–92 ± 3 for KYN, and 96 ± 1–103 ± 4 for 3HAA. The precision (%RSD) of repeatability and reproducibility is less than 3% and 6%, respectively. This method was used in a cross-sectional study with 81 participants aged 50–79 years, selected randomly from a local primary healthcare hospital’s sampling frame. A detectable amount of 3HAA was observed in all sweat samples, marking the first report of 3HAA presence in human sweat. Additionally, the results revealed that the 3HAA sweat levels increased with age analyzed in three different age groups ranging from 50–59, 60–69, and 70–79. These findings enhance our understanding of sweat profiles and their correlation with aging, potentially further improving early diagnosis, disease monitoring, and development of customized treatment programs for older adults.

Histamine in Fishery: A Five-Year Survey in Northern Italy

Histamine is a biogenic amine and an indicator of fishery product freshness and hygienic quality. The European Regulation EC 2073/2005 sets the standards for fish sample collection and establishes quantitative levels of histamine in fishery products to ensure consumer health and safety. This retrospective study presents data on histamine monitoring in fish and fishery products collected in northern Italy between 2018 and 2022. A total of 138 samples were analysed via enzyme-linked immunosorbent assay (ELISA) and then confirmed by high-performance liquid chromatography with diode-array detection (HPLC-DAD). Four samples found positive contained histamine levels above the legal limit. Monitoring via ELISA and HPLC-DAD can efficiently detect histamine in fish and fishery products and protect consumers’ health.

Coiled Coil Peptide Tiles (CCPTs): Expanding the Peptide Building Block Design with Multivalent Peptide Macrocycles.

Owing to their synthetic accessibility and protein-mimetic features, peptides represent an attractive biomolecular building block for the fabrication of artificial biomimetic materials with emergent properties and functions. Here, we expand the peptide building block design space through unveiling the design, synthesis, and characterization of novel, multivalent peptide macrocycles (96mers), termed coiled coil peptide tiles (CCPTs). CCPTs comprise multiple orthogonal coiled coil peptide domains that are separated by flexible linkers. The constraints, imposed by cyclization, confer CCPTs with the ability to direct programmable, multidirectional interactions between coiled coil-forming "edge" domains of CCPTs and their free peptide binding partners. These fully synthetic constructs are assembled using a convergent synthetic strategy via a combination of native chemical ligation and Sortase A-mediated cyclization. Circular dichroism (CD) studies reveal the increased helical stability associated with cyclization and subsequent coiled coil formation along the CCPT edges. Size-exclusion chromatography (SEC), analytical high-performance liquid chromatography (HPLC), and fluorescence quenching assays provide a comprehensive biophysical characterization of various assembled CCPT complexes and confirm the orthogonal colocalization between coiled coil domains within CCPTs and their designed on-target free peptide partners. Lastly, we employ molecular dynamics (MD) simulations, which provide molecular-level insights into experimental results, as a supporting method for understanding the structural dynamics of CCPTs and their complexes. MD analysis of the simulated CCPT architectures reveals the rigidification and expansion of CCPTs upon complexation, i.e., coiled coil formation with their designed binding partners, and provides insights for guiding the designs of future generations of CCPTs. The addition of CCPTs into the repertoire of coiled coil-based building blocks has the potential for expanding the coiled coil assembly landscape by unlocking new topologies having designable intermolecular interfaces.