Nicotinic Acid Research Articles

In(III) pyridinecarboxylate complexes: Composition, solution equilibria estimation, bioevaluation and interactions with HSA

Two In(III) – pyridinecarboxylates ([In(Pic)2(NO3)(H2O)] (InPic; HPic = picolinic acid), [In(HDpic)(Dpic)(H2O)2]·5H2O (InDpic; H2Dpic = dipicolinic acid), have been synthesized by one-step procedure. The complexes composition was confirmed by physicochemical analyses and X-ray diffraction confirmed molecular structure of both complexes. Moreover, complex species speciation was described in both systems by potentiometry and 1H NMR spectroscopy and mononuclear complex species were determined; [In(Pic)]2+ (logβ011 = 6.94(4)), [In(Pic)2]+ (logβ021 = 11.98(9)), [In(Dpic)]+ (logβ011 = 10.42(6)), [In(Dpic)2]− (logβ021 = 17.58(7)) and [In(Dpic)2(OH)]2− (logβ−121 = 10.18(6)). To confirm the complexes stability in 1 % DMSO, 1H NMR spectra were measured (immediately after dissolution up to 96 h). Antimicrobial and anticancer assays indicate a more significant sensitivity of S. aureus bacteria and MDA-MB-231 cancer cells to the InPic complex (IC50 = 25 and 340.7 μM) than to the InDpic (IC50 = 50 and 975.4 μM). The interaction and binding mechanism of picolinic/dipicolinic acid and their indium(III) complexes with HSA (human serum albumin) were studied using fluorescence and CD spectroscopy. The results confirmed that the studied compounds had bound successfully to HSA, and the binding parameters and constants (KSV, Kq, Kb) were calculated together with the number of binding sites. The binding forces were identified based on calculated thermodynamic parameters (ΔG, ΔH, ΔS). Synchronous spectra were used to study the microenvironment of Tyr and Trp residues and displacement assays revealed that site I was the preferred binding site. After binding, conformational changes were found to have occurred in the HSA molecule and the % α-helical content had decreased.

Picolinic acid-mediated Mn(II) activated periodate for ultrafast and selective degradation of emerging contaminants: Key role of high-valent Mn-oxo species

The utilization of periodate (PI, IO4-) in metal-based advanced oxidation processes (AOPs) for the elimination of emerging contaminants (ECs) have garnered significant attention. However, the commonly used homogeneous metal catalyst Mn(II) performs inadequately in activating PI. Herein, we exploited a novel AOP technology by employing the complex of Mn(II) with the biodegradable picolinic acid (PICA) to activate PI for the degradation of electron-rich pollutants. The performance of the Mn(II)-PICA complex surpassed that of ligand-free Mn(II) and other Mn(II) complexes with common aminopolycarboxylate ligands. Through scavenger, sulfoxide-probe transformation, and 18O isotope-labeling experiments, we confirmed that the dominant reactive oxidant generated in the Mn(II)-PICA/PI system was high-valent manganese-oxo species (Mn(V)=O). Due to its reliance on Mn(V)=O, the Mn(II)-PICA/PI process exhibited remarkable selectivity and strong anti-interference during EC oxidation in complex water matrices. Nine structurally diverse pollutants were selected for evaluation, and their lnkobs values in the Mn(II)-PICA/PI system correlated well with their electrophilic/nucleophilic indexes, EHOMO, and vertical IP (R2 = 0.79–0.94). Additionally, IO4- was converted into non-toxic iodate (IO3-) without producing undesired iodine species such as HOI, I2, and I3-. This study provides a novel protocol for metal-based AOPs using PI in combination with chelating agents and high-valent metal-oxo species formation during water purification.

Multi-omics study unravels gut microbiota and metabolites alteration in patients with Wilson's disease

Hepatolenticular degeneration (HLD), also known as Wilson's disease (WD), is a rare autosomal recessive disorder regarding copper metabolism. Whether gut microbiota imbalance is involved in developing HLD remains unknown. A comprehensive 16S rRNA amplicon sequencing, metagenomic sequencing, and metabonomic analysis were undertaken in patients with WD to analyze the composition and function profiles of gut microbiota in patients with WD. The data demonstrated differences in gut microbiota and metabolic pathways between WD patients and normal individuals, significantly decreasing bacterial richness and diversity. The levels of Selenomonaceae and Megamonas in WD patients are significantly higher than those in healthy individuals. The relative abundances of Roseburia inulinivorans in patients with WD are lower than in healthy individuals. Compared with healthy people, the level of metabolites in patients with WD is abnormal. Leucylproline, 5-Phenylvaleric Acid and N-Desmethylclobazam, which have nutritional and protective effects, are significantly reduced fecal metabolites in patients with WD. D-Gluconic acid, which can chelate metal ions, may be a potential treatment for WD. The positive correlation it demonstrates with Alistipes indistinctus and Prevotella stercora indicates potential bacteria able to treat WD. These metabolites are mainly related to the biosynthesis of antibiotics, alpha-linolenic acid metabolism, one carbon pool by folate, nicotinate and nicotinamide metabolism. In conclusion, the data from this study elucidate novel mechanisms describing how abnormal gut miccrobiota contribute to the pathogenesis of WD and outlines new molecules for the treatment of WD.

Metabolic Response to Small Molecule Therapy in Colorectal Cancer Tracked with Raman Spectroscopy and Metabolomics

AbstractDespite numerous screening tools for colorectal cancer (CRC), 25 % of patients are diagnosed with advanced disease. Novel diagnostic technologies that are early, accurate, and rapid are imperative to assess the therapeutic efficacy of clinical drugs and identify new biomarkers of treatment response. Here Raman spectroscopy (RS) was used to track metabolic reprogramming in KRAS‐mutant HCT116 and SW837 cells, and KRAS wild‐type CC cells. RS combined with multivariate analysis methods distinguished nonresponsive, partially responsive, and responsive cells treated with cetuximab, a monoclonal antibody for EGFR inhibition, sotorasib, a clinically approved KRAS inhibitor, and various doses of trametinib, an inhibitor of the MAPK pathway. Cells treated with a combination of subtoxic doses of trametinib and BKM120, an inhibitor of the PI3K pathway, showed a synergistic response between the two pathways. Using a supervised machine learning regression model, we established a scoring methodology trained to a priori predict therapeutic response to new treatment combinations. RS metabolites were verified with mass spectrometry, and enrichment pathways were identified, including amino acid, purine, and nicotinate and nicotinamide metabolism that differentiated monotherapy from combination therapy. Our approach may ultimately be applicable to patient‐derived primary cells and cultures of patient tumors to predict effective drugs for individualized care.

Biotransformation of carbamazepine and nicotine in juvenile American alligator (Alligator mississippiensis) in vitro hepatic S9 vs. in situ perfused liver

American alligators (Alligator mississippiensis) are apex predators and sentinel species in the coastal wetland ecosystem along the Gulf of Mexico. There is concern for alligator exposure and susceptibility to chemical contaminants due to their high trophic level and lower metabolic capability. At present, their hepatic biotransformation capacity to metabolize or detoxify contaminants has not been comprehensively determined. In this study, the hepatic biotransformation capability of juvenile American alligators to metabolize two commonly found environmental pharmaceuticals: carbamazepine (CBZ) or nicotine (NCT) was evaluated. The formation of their respective primary metabolites, i.e., carbamazepine-10,11-epoxide (CBZ-E) and cotinine (CTN), was evaluated at 10 μM (within the human therapeutic range). The in vitro S9 and a novel in situ liver perfusion assays were used to characterize and compare metabolic ability in isolated hepatic enzymes vs. whole organ (liver). For CBZ, the perfused livers exhibited only 30% of intrinsic formation clearance (CLf,int) relative to the S9 assay. The metabolism of NCT was not detectable in the S9 assay and was only observed in the perfused liver assay. Compared to the corresponding rat models (S9 or perfused livers),alligators' CLf,int was 2060% for CBZ and 50% for NCT of rats. Additionally, NCT exposure increased lactate levels in perfused livers indicating metabolic stress. This study provides insight into the hepatic capability of alligators to metabolize CBZ and NCT using an established in vitro (S9) system and a newly developed in situ liver perfusion system.

Halogen Bond Unlocks Ultra‐High Birefringence

AbstractAnisotropy is crucial for birefringence (Δn) in optical materials, but optimizing it remains a formidable challenge (Δn >0.3). Supramolecular frameworks incorporating π‐conjugated components are promising for achieving enhanced birefringence because of their structural diversity and inherent anisotropy. Herein, we first synthesized (C6H6NO2)+Cl− (NAC) and then constructed a halogen‐bonded supramolecular framework I+(C6H4NO2)− (INA) by halogen aliovalent substitution of Cl− with I+. The organic moieties are protonated and deprotonated nicotinic acid (NA), respectively. The antiparallel arrangement of birefringent‐active units in NAC and INA leads to significant differences in the bonding characteristics between the interlayer and intralayer domains. Moreover, the [O⋅⋅⋅I+⋅⋅⋅N] halogen bond in 1D [I+(C6H4NO2)−] chain exhibits stronger interactions and stricter directionality, resulting in a more pronounced in‐plane anisotropy between the intrachain and interchain directions. Consequently, INA exhibits exceptional birefringent performance, with a value of 0.778 at 550 nm, twice that of NAC (0.363 at 550 nm). This value significantly exceeds those of commercial birefringent crystals, such as CaCO3 (0.172 at 546 nm), and is the highest reported value among ultraviolet birefringent crystals. This work presents a novel design strategy that employs halogen bonds as connection sites and modes for birefringent‐active units, opening new avenues for developing high‐performance birefringent crystals.

Lipoprotein, Cholesterol, Treatment Strategies, and its Impact on Cardiovascular Diseases

A main cause of death internationally, cardiovascular (CV) illness accounted for about 31.4% of fatalities worldwide in 2012. According to estimates, a 33% decline in coronary heart disease (CHD) mortality in the United States between 1980 and 2000 was caused by a decrease in total cholesterol levels. Similar declines in CHD fatalities (varying from 19% to 46%) in other wealthy nations have been linked to lower total cholesterol levels. Lipoproteins are complex particles with a central core containing cholesterol esters and triglycerides surrounded by free cholesterol, phospholipids, and apolipoproteins, which facilitate lipoprotein formation and function. However, numerous individuals do not achieve LDL-C goal values because of statin resistance or adherence to statin medication. If cholesterol targets are not achieved with statins alone, alternative medicines include ezetimibe, fibrates, and nicotinic acid. In addition, people with familial high cholesterol levels (FH). Lipoprotein may act as a proinflammatory mediator that augments the lesion formation in atherosclerotic plaques. HDL metabolism represents a major target for the development of therapies intended to reduce the risk of atherosclerotic cardiovascular disease. Individual cardiovascular preventative treatments should be targeted largely at individuals at higher risk who will benefit most, with the prevention and treatment of dyslipidemia being viewed as a crucial component of those interventions. Since statins have been demonstrated to lessen the risk of serious vascular events by lowering low-density lipoprotein cholesterol (LDL-C), they continue to be the first-choice medication.

Halogen Bond Unlocks Ultra-High Birefringence.

Anisotropy is crucial for birefringence (Δn) in optical materials, but optimizing it remains a formidable challenge (Δn >0.3). Supramolecular frameworks incorporating π-conjugated components are promising for achieving enhanced birefringence because of their structural diversity and inherent anisotropy. Herein, we first synthesized (C6H6NO2)+Cl- (NAC) and then constructed a halogen-bonded supramolecular framework I+(C6H4NO2)- (INA) by halogen aliovalent substitution of Cl- with I+. The organic moieties are protonated and deprotonated nicotinic acid (NA), respectively. The antiparallel arrangement of birefringent-active units in NAC and INA leads to significant differences in the bonding characteristics between the interlayer and intralayer domains. Moreover, the [O⋅⋅⋅I+⋅⋅⋅N] halogen bond in 1D [I+(C6H4NO2)-] chain exhibits stronger interactions and stricter directionality, resulting in a more pronounced in-plane anisotropy between the intrachain and interchain directions. Consequently, INA exhibits exceptional birefringent performance, with a value of 0.778 at 550 nm, twice that of NAC (0.363 at 550 nm). This value significantly exceeds those of commercial birefringent crystals, such as CaCO3 (0.172 at 546 nm), and is the highest reported value among ultraviolet birefringent crystals. This work presents a novel design strategy that employs halogen bonds as connection sites and modes for birefringent-active units, opening new avenues for developing high-performance birefringent crystals.

Liquid chromatography-high-resolution mass spectrometry-based metabolomics revealing the effects of zearalenone and alpha-zearalenol on human endometrial cancer cells.

Human exposure to mycotoxins through food involve a mixture of compounds, which can be harmful to human health. The Fusarium fungal species are known to produce zearalenone (ZEN), a non-steroidal estrogenic mycotoxin, and its metabolite alpha-zearalenol (α-ZEL), both of which possess endocrine-disruptive properties. Given their potential harm to human health through food exposure, investigating the combined effects of ZEN and α-ZEL becomes crucial. Hence, the combined impact of ZEN and α-ZEL study hold significant importance. This in vitro study delves into the critical area, examining their combined impact on the proliferation and metabolic profile of endometrial cancer Ishikawa cells via sulforhodamine, clonogenic, proliferating cell nuclear antigen (PCNA) and liquid chromatography-high resolution mass spectrometry (LC-HRMS) based untargeted metabolomics. Low concentrations of ZEN (25nm), α-ZEL (10nm), or a combination of both were observed to significantly enhance cell proliferation of Ishikawa cells, as evidenced by PCNA immunostaining, immunoblotting as well and clonogenic assays. The metabolomics revealed the perturbations in glycerophospholipid metabolism, nicotinate and nicotinamide metabolism and phenylalanine, tyrosine, tryptophan biosynthesis provides valuable insights into potential mechanism by which these mycotoxins may facilitate cell proliferation. However, further investigations are warranted to comprehensively understand the implications of these findings and their possible implications for human health.

Plasma niacin is inversely associated with hyperlipidemia in participants with diabetes among Chinese adults

Evidence is limited regarding the association of plasma niacin with the risk of hyperlipidemia in participants with diabetes. We aimed to determine the relationship between plasma niacinamide/nicotinic acid and hyperlipidemia in participants with/without diabetes. Plasma niacinamide/nicotinic acid concentrations were measured using high-performance liquid chromatography-tandem mass spectroscopy. Multivariable logistic regression analyses were performed to evaluate the association between plasma niacin and hyperlipidemia in participants with diabetes and nondiabetes in a cross-sectional study. Compared to the first quartile, plasma nicotinamide, nicotinic acid, and niacin (nicotinamide plus nicotinic acid) were associated with a 54%, 50%, and 52% lower risk of hyperlipidemia in diabetic participants, respectively, but no significant association was observed in nondiabetic participants. These inverse associations persisted across subgroups stratified by sex, age, body mass index, smoking status, alcohol consumption, and physical activity. In addition, the fully adjusted odds ratios (95% confidence intervals) for hypercholesterolemia and hypertriglyceridemia among diabetic participants were 0.54 (0.38, 0.77) and 0.61 (0.44, 0.85), respectively, when comparing to the first quartile of plasma niacin concentrations (all Ptrend < .001). This study of 2647 participants observed that plasma niacin was inversely associated with hyperlipidemia in those with diabetes.

Suppressing hydrogen evolution reaction by constructing interfacial proton blocking layer for highly reversible zinc anode

Zinc (Zn) anodes are severely threatened by the hydrogen evolution reaction (HER) triggered by highly active water molecules. Motivated by the process of the HER in weakly acidic aqueous, we propose a strategy to construct a proton-blocking layer at the electrode-electrolyte interface by introducing robust hydrogen bonding, aiming to significantly suppress the HER. Isonicotinic acid (INA) possesses N and carboxyl sites that can form strong interactions with protons and can adsorb onto the surface of Zn. Thus, by introducing trace amounts (10 mM) of INA into the electrolyte, proton transfer at the interface can be effectively impeded. In addition, INA can also facilitate Zn uniform growth and inhibit dendrite formation. Consequently, the Zn//Zn symmetrical battery can perform for 3400 h at 1 mA/cm2@1 mAh/cm2, and the coulombic efficiency of the Zn//Cu battery can reach 99.74 % after 1800 cycles. Furthermore, due to the suppression of HER, the Zn//MnO2 batteries achieved high performance of 79.3 mAh/g after 2000 cycles at the current density of 2 A/g. This study provides a new approach to suppress HER and improve the stability of Zn anode.

Co-adsorbed self-assembled monolayer enables high-performance perovskite and organic solar cells

Self-assembled monolayers (SAMs) have become pivotal in achieving high-performance perovskite solar cells (PSCs) and organic solar cells (OSCs) by significantly minimizing interfacial energy losses. In this study, we propose a co-adsorb (CA) strategy employing a novel small molecule, 2-chloro-5-(trifluoromethyl)isonicotinic acid (PyCA-3F), introducing at the buried interface between 2PACz and the perovskite/organic layers. This approach effectively diminishes 2PACz’s aggregation, enhancing surface smoothness and increasing work function for the modified SAM layer, thereby providing a flattened buried interface with a favorable heterointerface for perovskite. The resultant improvements in crystallinity, minimized trap states, and augmented hole extraction and transfer capabilities have propelled power conversion efficiencies (PCEs) beyond 25% in PSCs with a p-i-n structure (certified at 24.68%). OSCs employing the CA strategy achieve remarkable PCEs of 19.51% based on PM1:PTQ10:m-BTP-PhC6 photoactive system. Notably, universal improvements have also been achieved for the other two popular OSC systems. After a 1000-hour maximal power point tracking, the encapsulated PSCs and OSCs retain approximately 90% and 80% of their initial PCEs, respectively. This work introduces a facile, rational, and effective method to enhance the performance of SAMs, realizing efficiency breakthroughs in both PSCs and OSCs with a favorable p-i-n device structure, along with improved operational stability.

Novel Highly Hydrophilic Resins with Attached Polymer Layers for Liquid Chromatography

The aim of this work was to the obtaining novel mixed-mode stationary phases with increased hydrophilicity and applying them in ion and hydrophilic interaction liquid chromatography. The resins were obtained by the sequential covalent attachment of branched polyethylenimine and polyelectrolytes synthesized from diepoxide and a secondary amine on the surface of epoxidized polystyrene–divinylbenzene. To increase the shielding degree of the polymer substrate, an additional polymerization of glycidol was carried out in the functional layer of the sorbent at an increased pH of the reaction medium. The synthesized phases possessed increased hydrophilicity compared to most resins based on a styrene–divinylbenzene copolymer with covalently attached layers. This was evidenced in the ion chromatography mode by a decrease in the relative retention of polarizable anions, weakly hydrated oxyhalides (up to a change in the elution order of the bromate), and haloacetic acids. In the hydrophilic interaction liquid chromatography mode, an increased hydrophilicity of the phases was confirmed by an increase in the retention factors of polar analytes, as well as by the reversal of the elution order of ascorbic and nicotinic acids as compared to the phases based on polystyrene–divinylbenzene presented in the literature. The low efficiency of the obtained stationary phases in the ion chromatography mode was noted, which is associated with slow mass transfer in the bulk polymer functional layer. The negative impact of the polymer layer on efficiency in hydrophilic interaction liquid chromatography is less pronounced due to the presumably smaller thickness of the part of the functional layer involved in this mode. The proposed method for the synthesis of resins ensures an increase in the efficiency, selectivity, and separation ability of sorbents in the hydrophilic interaction liquid chromatography mode as compared to phases based on a styrene–divinylbenzene copolymer described previously in the literature. The resulting highly hydrophilic resins makes it possible to separate a mixture of 9 nitrogenous bases and nucleosides in 18 min, 6 vitamins in 24 min, and 8 sugars in 11 min. Thus, the method of substrate hydrophilization proposed in this work is promising for improving the chromatographic characteristics of phases in the hydrophilic interaction liquid chromatography mode and can be used to create sorbents with increased selectivity and efficiency.

Soil and stone terraces offset the negative impacts of sloping cultivation on soil microbial diversity and functioning by protecting soil carbon

Cultivation of sloping land is a main cause for soil erosion. Conservation practices, such as soil and stone terraces, may reduce the impacts of erosion but their impacts on soil microbial diversity and functioning related to carbon (C) and nutrient metabolisms remain unclear. This study was conducted to evaluate the effects of slope gradients (5°, 8°, 15°, 25°) and conservation practices (cultivated, uncultivated, soil terrace, and stone terrace) on bacterial and fungal diversities, metagenomic and metabolomic functioning associated with basic soil properties. Our results showed that steep slopes at 25° significantly decreased soil pH, silt percentage, and bacterial and fungal abundances, but that soil and stone terraces increased soil organic C (SOC), silt and clay contents, and fungal abundance compared to sloping cultivated lands. In addition, soil and stone terraces increased both bacterial and fungal alpha diversities, and relative abundances of Crenarchaeota, Nitrospirota, and Latescibacterota, but reduced the proportions of Actinobacteriota and Patescibacteria, thus shifting microbial beta diversities, which were significantly associated with increased SOC and silt content. For metagenomics, soil and stone terraces greatly increased the relative abundance of functional genes related to Respiration, Virulence, disease and defense, Stress response, and nitrogen and potassium metabolisms, such as Denitrification and Potassium homeostasis. For soil metabolomics, a total of 22 soil metabolites was enriched by soil and stone terraces, such as Lipids and lipid-like molecules (Arachidonic acid, Gamma-Linolenic acid, and Pentadecanoic acid), and Organoheterocyclic compounds (Adenine, Laudanosine, Methylpyrazine, and Nicotinic acid). To sum up, soil and stone terraces could reduce some of the negative impacts of steep slope cultivation on soil microbial diversity as well as their metagenomic and metabolomic functioning related to C and nutrient metabolism useful for soil health improvement, potentially bolstering the impact of sustainable practices in erosion hotspots around the world.

Growth and optically active third-order nonlinear optical material: nicotinic acid as optical limiters

Growth and optically active third-order nonlinear optical material: nicotinic acid as optical limiters

Harnessing Abiotic Defence Inducers for Effective Management of Pod Rot of Mungbean

Pod rot is a significant issue for mung bean plants, causing substantial reductions in yield and quality. In this study, several defence inducers, including salicylic acid (SA), nicotinic acid (NA), indole butyric acid (IBA), chitosan, and benzothiadiazole (BTH), were applied as foliar sprays to assess their effectiveness in enhancing resistance to pod rot in field conditions. The results indicated that benzothiadiazole -treated plants experienced a marked reduction in disease severity of 18.667% compared to untreated plants (control) with 36.177%. This indicated that benzothiadiazole has antifungal properties, decreases disease severity, and stimulates defence mechanisms in Mung bean against pod rot.

Fine-mapping the CYP2A6 regional association with nicotine metabolism among African American smokers.

The nicotine metabolite ratio (NMR; 3'hydroxycotinine/cotinine) is a stable biomarker for CYP2A6 enzyme activity and nicotine clearance, with demonstrated clinical utility in personalizing smoking cessation treatment. Common genetic variation in the CYP2A6 region is strongly associated with NMR in smokers. Here, we investigated this regional association in more detail. We evaluated the association of CYP2A6 single-nucleotide polymorphisms (SNPs) and * alleles with NMR among African American smokers (N = 953) from two clinical trials of smoking cessation. Stepwise conditional analysis and Bayesian fine-mapping were undertaken. Putative causal variants were incorporated into an existing African ancestry-specific genetic risk score (GRS) for NMR, and the performance of the updated GRS was evaluated in both African American (n = 953) and European ancestry smokers (n = 933) from these clinical trials. Five independent associations with NMR in the CYP2A6 region were identified using stepwise conditional analysis, including the deletion variant CYP2A6*4 (beta = -0.90, p = 1.55 × 10-11). Six putative causal variants were identified using Bayesian fine-mapping (posterior probability, PP = 0.67), with the top causal configuration including CYP2A6*4, rs116670633, CYP2A6*9, rs28399451, rs8192720, and rs10853742 (PP = 0.09). Incorporating these putative causal variants into an existing ancestry-specific GRS resulted in comparable prediction of NMR within African American smokers, and improved trans-ancestry portability of the GRS to European smokers. Our findings suggest that both * alleles and SNPs underlie the association of the CYP2A6 region with NMR among African American smokers, identify a shortlist of variants that may causally influence nicotine clearance, and suggest that portability of GRSs across populations can be improved through inclusion of putative causal variants.

Decoration of recycled battery graphite functionalized with gold nanoparticles/poly(nicotinic acid) for detection of bifenazate pesticide in tea and food samples

Bifenazate (BF), is a type of carbamate acaricide effective at controlling mite parasites on crops and ornamental plants. In this work, a recycled dry zinc-carbon battery graphite electrode decorated with gold nano particles/poly nicotinic acid, AuNPs/poly(NA)-BGE, was applied as the working electrode for the electrochemical measurement of bifenazate (BF). The working electrode (BGE) was functionalized by 10 electropolymerization voltammetric cycles of poly nicotinic acid poly (NA) following by 30 s of amperometric deposition of gold nanoparticles (AuNPs) to produce the final AuNPs/poly(NA)-BGE electrode in a two-step procedure. “Electrochemical and morphological characterization of the sensor at its different production steps was performed using electrochemical impedance spectroscopy (EIS), cyclic voltammetry (CV), scanning electron microscopy (SEM), atomic force microscopy (AFM), energy dispersive X-ray spectroscopy (EDX) techniques and Transmission electron microscopy (TEM).” The highest peak current response was attained using pH 6.0 in 0.1 M phosphate buffer. The sensor exhibited a linearity range from (1 × 10−4–1 × 10−8 M) that is equivalent to 30.035–3.00 × 10−3 µg/mL with limits of detection LOD and quantification 3.3 × 10−11 M (9.91 × 10−6 µg/mL) and 1.00 × 10−10 M (3.00 × 10−5 µg/mL), respectively. Finally, with a recovery range of (96.3 %–102.6 %) and an RSD of (0.17 %–0.64 %), BF in Kenyan green and black tea, strawberry, tomato, cucumber and its commercial formulation Duramite® 24 %SC was successfully quantified which indicates the promising applicability of the presented sensor in different matrixes.

Unraveling phytoremediation mechanisms of the common reed (Phragmites australis) suspension cells towards ciprofloxacin: Xenobiotic transformation and metabolic reprogramming

Phytoremediation is an effective solution to treat pollution with antibiotic compounds in aquatic environments; however, the underlying mechanisms for plants to cope with antibiotic pollutants are obscure. Here we used cell suspension culture to investigate the distribution and transformation of ciprofloxacin (CIP) in common reed (Phragmites australis) plants, as well as the accompanying phenotypic and metabolic responses of plants. By means of radioactive isotope labelling, we found that in total 68 % of CIP was transformed via intracellular Phase I transformation (reduction and methylation), Phase Ⅱ conjugation (glycosylation), and Phase Ⅲ compartmentalization (cell-bound residue formation mainly in cell walls, 23 %). The reduction and glycosylation products were secreted by the cells. To mitigate stress induced by CIP and its transformation products, the cells activated the defense system by up-regulating both intra- and extra-cellular antioxidant metabolites (e.g., catechin, l-cystine, and dehydroascorbic acid), anti-C/N metabolism disorder metabolites (e.g., succinic acid), secreting signaling (e.g., nicotinic acid), and anti-stress (e.g., allantoin) metabolites. Notably, the metabolic reprogramming could be involved in the CIP transformation process (e.g., glycosylation). Our findings reveal the strategy of wetland plants to cope with the stress from CIP by transforming the xenobiotic compound and reprogramming metabolism, and provide novel insights into the fate of antibiotics and plant defense mechanisms during phytoremediation.

Alterations in the Blood Kynurenine Pathway Following Long-Term PM2.5 and PM10 Exposure: A Cross-Sectional Study.

Human exposure to PM2.5 and PM10 has been linked to respiratory and cardiovascular diseases through inflammation activation. The kynurenine pathway is associated with inflammation, and it is necessary to investigate the effects of long-term PM2.5 and PM10 exposure on this pathway. This study aimed to conduct a cross-sectional analysis of long-term PM2.5 and PM10 exposure's impact on the kynurenine pathway using proton NMR spectroscopy (1H-NMR). The participants were divided into a low-PM-exposure group (LG; n = 98), and a high-PM-exposure group (HG; n = 92). The metabolites of tryptophan were determined in blood by 1H-NMR. Serotonin, cinnabarinic acid, xanthurenic acid, 5-hydroxytryptophan, indoleacetic acid, tryptamine, melatonin, L-tryptophan, 5-hydroxy-L-tryptophol, indoxyl, 2-aminobenzoic acid, 5-HTOL, hydroxykynurenine, L-3-hydroxykynurenine, N-formyl kynurenine, 3-hydroxy anthranilic acid, kynurenic acid, and picolinic acid significantly increased (p < 0.05) in the HG group. Conversely, NAD and quinolinic acid significantly decreased in the HG group compared to the LG group. The enzyme activities of indoleamine 2,3-dioxygenase and formamidase significantly decreased, while kynureninase and kynurenine monooxygenase significantly increased. The kynurenine pathway is linked to inflammation and non-communicable diseases. Disruption of the kynurenine pathway from particulate matter might promote diseases. Reducing exposure to the particulate matter is crucial for preventing adverse health effects.