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1.
Rapid Commun Mass Spectrom ; 38(16): e9847, 2024 Aug 30.
Article in English | MEDLINE | ID: mdl-38890224

ABSTRACT

RATIONALE: The sources and chemical compositions of organic aerosol (OA) exert a significant influence on both regional and global atmospheric conditions, thereby having far-reaching implications on environmental chemistry. However, existing mass spectrometry (MS) methods have limitations in characterizing the detailed composition of OA due to selective ionization as well as fractionation during cold-water extraction and solid-phase extraction (SPE). METHODS: A comprehensive MS study was conducted using aerosol samples collected on dusty, clean, and polluted days. To supplement the data obtained from electrospray ionization (ESI), a strategy for analyzing OAs collected using the quartz fiber filter directly utilizing laser desorption ionization (LDI) was employed. Additionally, the ESI method was conducted to explore suitable approaches for determining various OA compositions from samples collected on dusty, clean, and polluted days. RESULTS: In situ LDI has the advantages of significantly reducing the sample volume, simplifying sample preparation, and overcoming the problem of overestimating sulfur-containing compounds usually encountered in ESI. It is suitable for the characterization of highly unsaturated and hydrophobic aerosols, such as brown carbon-type compounds with low volatility and high stability, which is supplementary to ESI. CONCLUSIONS: Compared with other ionization methods, in situ LDI helps provide a complementary description of the molecular compositions of OAs, especially for analyzing OAs in polluted day samples. This method may contribute to a more comprehensive MS analysis of the elusive compositions and sources of OA in the atmosphere.

2.
Environ Sci Technol ; 58(25): 10991-11002, 2024 Jun 25.
Article in English | MEDLINE | ID: mdl-38829627

ABSTRACT

Peatland wildfires contribute significantly to the atmospheric release of light-absorbing organic carbon, often referred to as brown carbon. In this study, we examine the presence of nitrogen-containing organic compounds (NOCs) within marine aerosols across the Western Pacific Ocean, which are influenced by peatland fires from Southeast Asia. Employing ultrahigh-resolution Fourier transform ion cyclotron resonance mass spectrometry (FT-ICR MS) in electrospray ionization (ESI) positive mode, we discovered that NOCs are predominantly composed of reduced nitrogenous bases, including CHN+ and CHON+ groups. Notably, the count of NOC formulas experiences a marked increase within plumes from peatland wildfires compared to those found in typical marine air masses. These NOCs, often identified as N-heterocyclic alkaloids, serve as potential light-absorbing chromophores. Furthermore, many NOCs demonstrate pyrolytic stability, engage in a variety of substitution reactions, and display enhanced hydrophilic properties, attributed to chemical processes such as methoxylation, hydroxylation, methylation, and hydrogenation that occur during emission and subsequent atmospheric aging. During the daytime atmospheric transport, aging of aromatic N-heterocyclic compounds, particularly in aliphatic amines prone to oxidation and reactions with amine, was observed. The findings underscore the critical role of peatland wildfires in augmenting nitrogen-containing organics in marine aerosols, underscoring the need for in-depth research into their effects on marine ecosystems and regional climatic conditions.


Subject(s)
Aerosols , Nitrogen/analysis , Organic Chemicals/analysis , Wildfires , Pacific Ocean
3.
Environ Res ; 257: 119251, 2024 Sep 15.
Article in English | MEDLINE | ID: mdl-38815714

ABSTRACT

The bioavailable diverse dissolved organic matter (DOM) present in glacial meltwater significantly contributes to downstream carbon cycling in mountainous regions. However, the comprehension of molecular-level characteristics of riverine DOM, from tributary to downstream and their fate in glacier-fed desert rivers remains limited. Herein, we employed spectroscopic and high-resolution mass spectrometry techniques to study both optical and molecular-level characteristics of DOM in the Tarim River catchment, northwest China. The results revealed that the DOC values in the downstream were higher than those in the tributaries, yet they remained comparable to those found in other glacier-fed streams worldwide. Five distinct components were identified using EEM-PARAFAC analysis in both tributary and downstream samples. The dominance of three protein-like components in tributary samples, contrasting with a higher presence of humic-like components in downstream samples, which implied that the dilution and alterations of the glacier DOM signature and overprinting with terrestrial-derived DOM. Molecular composition revealed that thousands of compounds with higher molecular weight and increased aromaticity were transformed, generated and introduced from terrestrial inputs during downstream transportation. The twofold rise in polycyclic aromatic and polyphenolic compounds observed downstream compared to tributaries indicated a greater influx of terrestrial organic matter introduced into the downstream during water transportation. The study suggests that the glacier-sourced DOM experienced minimal photodegradations, with limited influence from human activities, while also being shaped by terrestrial inputs during its transit in the alpine-arid region. This unique scenario offers valuable insights into comprehending the fate of DOM originating from glacial meltwater in arid mountainous regions.


Subject(s)
Ice Cover , Rivers , China , Rivers/chemistry , Ice Cover/chemistry , Environmental Monitoring/methods , Organic Chemicals/analysis , Water Pollutants, Chemical/analysis , Humic Substances/analysis , Mass Spectrometry , Desert Climate
4.
J Environ Manage ; 354: 120296, 2024 Mar.
Article in English | MEDLINE | ID: mdl-38341910

ABSTRACT

It is crucial for understanding the variations of carbon and nutrient pools within the ecosystems during long-term vegetation restoration to accurately assess the effects of different ecological restoration patterns. However, the long-term spatio-temporal variations of carbon and nutrient pools under different vegetation types remain unclear. The sites for long-term natural and planted forests (i.e., Natural secondary forest, Pinus tabulaeformis planted forest, Platycladus orientalis planted forest, and Robinia pseudoacacia planted forest) on the northeastern Loess Plateau, China were selected, to measure and analyze the differences and interannual variations of vegetation attributes at four synusiae and soil properties at 0-100 cm over the period of 12 years (2006-2017). The principal component analysis (PCA) and Mantel test were also conducted to explore the relationships among vegetation attributes, soil properties, and carbon and nutrient pools. The results showed that: compared with the planted forests, the natural secondary forest had lower arborous biomass (84.21 ± 1.53 t hm-2) and higher understory biomass and plant heights. Compared to planted forests, the secondary forest had higher soil carbon and nitrogen contents (13.74 ± 3.50 g kg-1 and 1.16 ± 0.34 g kg-1). The soil carbon pool in the secondary forest was 22.0% higher than planted forests, while the vegetation carbon pool in the P. tabulaeformis was 75.5% higher than other forests. Principal component analysis (PCA) and Mantel test revealed that vegetation attributes and soil properties had significant correlations with carbon and nutrient pools, especially at the arborous synusia (p < 0.01). The findings indicated that in the ecologically fragile Loess Plateau region, the selection of appropriate vegetation restoration types should be guided by varying ecological restoration goals and benefits, aiming to expected ecological outcomes. This insight offers a strategic implication for forest management that is tailored to improve carbon and nutrient pools in areas with similar environmental conditions.


Subject(s)
Carbon , Ecosystem , Carbon/analysis , Forests , Soil , China
5.
J Ethnopharmacol ; 324: 117745, 2024 Apr 24.
Article in English | MEDLINE | ID: mdl-38228231

ABSTRACT

ETHNOPHARMACOLOGICAL RELEVANCE: Jin-Gui-Shen-Qi Wan (JGSQW) is a traditional Chinese medicine formula that has been traditionally used to alleviate urinary system ailments such as frequent urination and polyuria. Clinical studies have indicated that when combined with hypoglycaemic drugs, JGSQW exhibits a synergistic effect and can improve diabetic nephropathy (DN), yet its underlying mechanism and targets remain unclear. AIM OF THE STUDY: This study aims to investigate the therapeutic efficacy of JGSQW and its underlying mechanisms using a DN db/db mouse model. MATERIALS AND METHODS: Ultrahigh-performance liquid chromatography coupled with mass spectrometry was utilized to analyse the primary active compounds, blood levels, and pharmacokinetics of JGSQW. Additionally, the therapeutic effects of JGSQW and metformin on blood glucose levels, lipid levels, renal function, and renal pathology in diabetic nephropathy mice were investigated using a db/db mouse model. Proteomic analysis was carried out to identify the primary target of JGSQW in treating DN. The mechanism of action was verified by western blotting, immunohistochemistry, and immunofluorescence. Then, molecular docking and molecular dynamics, transfection, drug affinity responsive target stability (DARTS) assay and cell thermal migration assay (CETSA) further validated the targeted binding effect. RESULTS: JGSQW combined with metformin significantly improved the blood glucose levels, blood lipids, renal function, and renal pathology of DN mice. JGSQW mainly exerted its therapeutic effect on DN by targeting major histocompatibility complex class II (MHC class II) molecules. Immunohistochemistry results showed that JGSQW inhibited the expression of collagen I, fibronectin, and alpha smooth muscle actin (α-SMA) expression. Immunofluorescence and Western blot results showed that JGSQW inhibited the expression of H2-Ab1 and H2-Aa, which are MHC class II molecules, thereby suppressing CD4+ T-cell infiltration and improving diabetic kidney fibrosis. The binding ability of paeoniflorin to H2-Aa was predicted and verified by molecular, DARTS, and CETSA assays. Treatment with 80 µM paeoniflorin effectively alleviated high glucose-induced injury in the MPC-5 injury model. H2-Aa was overexpressed at this model concentration, and Western blotting further confirmed that paeoniflorin reduced glomerular podocyte fibrosis by regulating H2-Aa. CONCLUSIONS: JGSQW combined with metformin may have a synergistic effect to alleviates renal fibrosis in diabetic nephropathy by downregulating immune complex MHC class II molecules and attenuating the antigen presentation effect of MHC class II on CD4.


Subject(s)
Diabetes Mellitus , Diabetic Nephropathies , Glucosides , Metformin , Monoterpenes , Mice , Animals , Diabetic Nephropathies/pathology , Blood Glucose , Molecular Docking Simulation , Proteomics , Signal Transduction , Fibrosis , Histocompatibility Antigens Class II/pharmacology , Histocompatibility Antigens Class II/therapeutic use , Metformin/pharmacology , Metformin/therapeutic use
6.
Water Res ; 249: 120881, 2024 Feb 01.
Article in English | MEDLINE | ID: mdl-38016225

ABSTRACT

Pharmaceuticals and personal care products (PPCPs) are emerging contaminants that have raised urgent environmental issues. The dissolved organic matter (DOM) plays a pivotal role on PPCPs' migration and transformation. To obtain a comprehensive understanding of the occurrence and distribution of PPCPs, a seasonal sampling focused on the riverine system in coastal zone, Tianjin, Bohai Rim was conducted. The distribution and transformation of thirty-three PPCPs and their interaction with DOM were investigated, and their sources and ecological risks were further evaluated. The total concentration of PPCPs ranges from 0.01 to 197.20 µg/L, and such value is affected by regional temperature, DOM and land use types. PPCPs migration at soil-water interface is controlled by temperature, sunlight, water flow and DOM. PPCPs have a high affinity to the protein-like DOM, while the humus-like DOM plays a negative influence and facilitates PPCPs' degradation. It is also found that protein-like DOM can represent point source pollution, while humus-like substances indicate non-point source (NPS) emission. Specific PPCPs can be used as markers to trace the source of domestic discharge. Additionally, daily use PPCPs such as ketoprofen, caffeine and iopromide are estimated to be the main risk substances, and their ecological risk varies on space, season and river hydraulic condition.


Subject(s)
Cosmetics , Water Pollutants, Chemical , Seasons , Dissolved Organic Matter , Environmental Monitoring , Water Pollutants, Chemical/analysis , Cosmetics/analysis , China , Water , Soil , Rivers , Pharmaceutical Preparations
7.
Chin Med ; 18(1): 130, 2023 Oct 12.
Article in English | MEDLINE | ID: mdl-37828620

ABSTRACT

BACKGROUND: Jin-Gui-Shen-Qi Wan (JGSQ) has been used in China for thousands of years to treat various ailments, including frequent urination, blurred vision, and soreness in the waist and knees. It has traditional therapeutic advantages in improving eye diseases. AIM OF THE STUDY: Clinical studies have confirmed the therapeutic efficacy of JGSQ in improving diabetes and vision; however, its efficacy and pharmacological effects in treating diabetic retinopathy (DR) remain unclear. Therefore, the aim of this study was to investigate the specific pharmacological effects and potential mechanisms of JGSQ in improving DR through a db/db model. MATERIALS AND METHODS: db/db mice were given three different doses of orally administered JGSQ and metformin for 8 weeks, and then PAS staining of the retinal vascular network patch, transmission electron microscopy, H&E staining, and TUNEL staining were performed to determine the potential role of JGSQ in improving DR-induced neuronal cell apoptosis. Furthermore, network pharmacology analysis and molecular docking were carried out to identify the main potential targets of JGSQ, and the efficacy of JGSQ in improving DR was evaluated through western blotting and immunofluorescence staining, revealing its mechanism of action. RESULTS: According to the results from H&E, TUNEL, and PAS staining of the retinal vascular network patch and transmission electron microscopy, JGSQ does not have an advantage in improving the abnormal morphology of vascular endothelial cells, but it has a significant effect on protecting retinal ganglion cells from apoptosis. Through network pharmacology and molecular docking, AKT, GAPDH, TNF, TP53, and IL-6 were identified as the main core targets of JGSQ. Subsequently, through western blot and immunofluorescence staining, it was found that JGSQ can inhibit HIF-1α, promote p-AKT expression, and inhibit TP53 expression. At the same time, inhibiting the release of inflammatory factors protects retinal ganglion cells and improves apoptosis in DR. CONCLUSION: These results indicated that in the db/db DR mouse model, JGSQ can inhibit the expression of inflammatory cytokines and protect retinal ganglion cells from apoptosis, possibly by modulating the Akt/HIF-1α pathway.

8.
Sci Total Environ ; 903: 166842, 2023 Dec 10.
Article in English | MEDLINE | ID: mdl-37689212

ABSTRACT

Natural dissolved organic matter (DOM) is one of the Earth's dynamic carbon pools and a key intermediate in the global carbon cycle. Photochemical processes potentially affect DOM composition and activity in surface water. Suspended particulate matter (SPM) is the integral component of slow-moving rivers, and holds the potential for photochemical reactivity. To further investigate the influence of SPM on DOM photochemical transformation, this study conducted experiments comparing samples with and without SPM irradiated under simulated sunlight. Surface water samples from slow-moving urban rivers were collected. DOM optical characteristics and molecular features obtained by Fourier transform ion cyclotron resonance mass spectrometry (FT-ICR MS) were investigated. Photolabile DOM was enriched in unsaturated and highly aromatic terrestrial substances. Photoproduced DOM had low aromaticity and was dominated by saturated aliphatics, protein-like substances, and carbohydrates. Study results indicated that the presence of SPM had a nonnegligible impact on the molecular traits of DOM, such as composition, molecular diversity, photolability, and bioavailability during photochemical reactions. In the environment affected by SPM, molecules containing heteroatoms exhibit higher photosensitivity. SPM promotes the photochemical transformation of a wider range of chemical types of photolabile DOM, particularly nitrogen-containing compounds. This study provides an essential insight into the more precise simulation of photochemical reactions of DOM influenced by SPM occurring in natural rivers, contributing to our understanding of the global carbon cycle from new theoretical perspectives.

9.
MedComm (2020) ; 4(5): e359, 2023 Oct.
Article in English | MEDLINE | ID: mdl-37692109

ABSTRACT

Purines and purinergic receptors are widely distributed throughout the human body. Purine molecules within cells play crucial roles in regulating energy metabolism and other cellular processes, while extracellular purines transmit signals through specific purinergic receptors. The ubiquitous purinergic signaling maintains normal neural excitability, digestion and absorption, respiratory movement, and other complex physiological activities, and participates in cell proliferation, differentiation, migration, and death. Pathological dysregulation of purinergic signaling can result in the development of various diseases, including neurodegeneration, inflammatory reactions, and malignant tumors. The dysregulation or dysfunction of purines and purinergic receptors has been demonstrated to be closely associated with tumor progression. Compared with other subtypes of purinergic receptors, the P2X7 receptor (P2X7R) exhibits distinct characteristics (i.e., a low affinity for ATP, dual functionality upon activation, the mediation of ion channels, and nonselective pores formation) and is considered a promising target for antitumor therapy, particularly in patients with poor response to immunotherapy This review summarizes the physiological and pathological significance of purinergic signaling and purinergic receptors, analyzes their complex relationship with tumors, and proposes potential antitumor immunotherapy strategies from tumor P2X7R inhibition, tumor P2X7R overactivation, and host P2X7R activation. This review provides a reference for clinical immunotherapy and mechanism investigation.

10.
Se Pu ; 41(8): 662-672, 2023 Aug.
Article in Chinese | MEDLINE | ID: mdl-37534553

ABSTRACT

Dissolved organic matter (DOM) is a highly complex and heterogeneous mixture that exists in various environments, including rivers, oceans, soils, and atmospheric aerosols. DOM plays a crucial role in biogeochemical cycles and significantly influences the environment by regulating water quality, changing the climate, and transporting pollutants. Therefore, clarifying the detailed molecular composition of DOM is essential to obtain a better understanding of its physical and chemical properties, thereby enabling further elucidation of its biogeochemical behavior. In this study, Fourier transform ion cyclotron resonance mass spectrometry (FT-ICR MS) combined with quadrupole detection (QPD) was used to conduct the online ultra performance liquid chromatography (UPLC)-MS analysis of DOM in water, aerosol, and soil samples collected in Tianjin, China. The samples were extracted with pure water and filtered through a glass fiber membrane (0.45 µm). The DOM in the samples was then enriched by solid-phase extraction (SPE) and redissolved in water-acetonitrile (1∶1, v/v) at mass concentration of 200 mg/L for the LC-MS experiments. The mobile phases used for UPLC were water containing 0.1% (v/v) formic acid (A) and acetonitrile containing 0.1% (v/v) formic acid (B). The gradient elution procedure was as follows: 0-5 min, 0B; 5-11 min, 0B-95%B; 11-25 min, 95%B; 25-28 min, 95%B-0B; 28-30 min, 0B. The flow rate was 0.1 mL/min, and the injection volume was 10 µL. The UV wavelength was set at 274 nm. MS detection was performed in negative electrospray ionization (ESI(-)) mode with a capillary voltage of 5.0 kV, and the MS data were collected in broadband (m/z 150-1000) and QPD modes. The transient data size was set to 2M, the free induction decay signal length was 0.74 s, and the ion accumulation time was 0.030 s. Four chromatographic peaks were observed in the chromatograms. The first peak was identified as salt adduct compounds containing sodium formate. The three other peaks contained complex components, such as oxygen-rich, unsaturated tannin-like compounds, as well as low-oxygen, highly saturated lignin-like and protein/amino-like compounds. UPLC-FT-ICR MS was suitable for assigning the detailed elemental compositions of the DOM samples. UPLC effectively improved the ionization efficiency of difficult-to-ionize compounds and enhanced the detection accuracy of MS. Indeed, MS peaks with a mass difference of as small as 3.4 mDa were well identified. A total of 12027, 15593, and 8029 peaks in the mass spectra of the water, aerosol, and soil samples, respectively, were assigned to known elemental formulae. Peaks Ⅱ and Ⅲ were hydrophilic components mainly including CHNO and CHO compounds. Compared with peak Ⅱ, peak Ⅲ exhibited a significant increase in CHNOS and CHOS, indicating that UPLC exerted a certain separation effect on these compounds. Furthermore, the aerosol samples contained a higher concentration of sulfur-containing compounds than the water and soil samples, primarily because of the abundance of organic sulfates present in atmospheric and cloud water. Data processing and graphic visualization revealed that the unique components in the water samples mainly appeared in the area of 0.1

11.
Phytomedicine ; 115: 154828, 2023 Jul.
Article in English | MEDLINE | ID: mdl-37116386

ABSTRACT

BACKGROUND: Retinitis pigmentosa (RP) refers to a group of progressive photoreceptor degenerative diseases. The activation of microglia has been reported to play an important role in the photoreceptor degeneration in RP retinal. Bujing Yishi tablets (BJYS), a Chinese herbal medicine, has been used to treat retinal diseases in China with desirable effect in improving visual function. However, the mechanisms underlying the efficacy of BJYS treatment in RP are not yet fully understood. PURPOSE: Based on the preliminary experiments, this study aimed to investigate the therapeutic mechanism involved in treating N-Methyl-N-Nitrosourea (MNU)-induced retinal degeneration of RP with BJYS. METHODS: To explore the efficacy of BJYS, a rat experimental RP model was established through intraperitoneal injection of MNU (50 mg/kg). Two experiment was carried out. After the treatment, we conducted H&E, TUNEL, retinal cytokine levels and IBA-1 expression in microglia to confirm the impact on RP model. The specific mechanism of action of BJYS tablet was assessed by western blot, real-time polymerase chain reaction (RT-PCR), and immunofluorescence to determine the mRNA and protein expression levels involved in clarifying the effectiveness of BJYS exerted through P2X7R/CX3CL1/CX3CR1 pathway. RESULTS: Significant alleviation of retinal morphological structure and photoreceptor degeneration by BJYS treatment was observed in the retinal of MNU-induced RP rats, BJYS prevented the reduction of ONL thickness and decreased the level of apoptotic cells in ONL. It also inhibited microglia overactivation and reduced retinal levels of IL-1ß, IL-6, TNF-α. In addition, BJYS decreased the protein expression and mRNA expression of P2X7, CX3CL1 and CX3CR1 and reduced the phosphorylation of p38 MAPK. CONCLUSION: In summary, this study suggested that BJYS treatment could alleviate photoreceptors degeneration of RP by inhibiting microglia overactivation and inflammation through the P2X7R/CX3CL1/CX3CR1 pathway. These effects suggest that BJYS tablets may serve as a promising oral therapeutic agent for RP.


Subject(s)
Retinal Degeneration , Retinitis Pigmentosa , Rats , Animals , Retinitis Pigmentosa/drug therapy , Retinitis Pigmentosa/metabolism , Photoreceptor Cells/metabolism , Retina , Retinal Degeneration/chemically induced , Cell Death , Nitrosourea Compounds/adverse effects , Nitrosourea Compounds/metabolism , Apoptosis , Disease Models, Animal , Chemokine CX3CL1/adverse effects , Chemokine CX3CL1/metabolism , CX3C Chemokine Receptor 1/metabolism
13.
Molecules ; 28(3)2023 Jan 28.
Article in English | MEDLINE | ID: mdl-36770938

ABSTRACT

Sauce-flavor Baijiu is one of the most complex and typical types of traditional Chinese liquor, whose trace components have an important impact on its taste and quality. Fourier transform ion cyclotron resonance mass spectrometry (FT-ICR MS) is one of the most favorable analytical tools to reveal trace molecular components in complex samples. This study analyzed the chemical diversity of several representative sauce-flavor Baijiu using the combination of electrospray ionization (ESI) and FT-ICR MS. The results showed that ESI+ and ESI- exhibited different chemical features characteristic of trace components. Overall, sauce-flavor Baijiu was dominated by CHO class compounds, and the main specific compound types were aliphatic, highly unsaturated with low oxygen, and peptide-like compounds. The mass spectral parameters resolved by FT-ICR MS of several well-known brands were relatively similar, whereas the greatest variability was observed from an internally supplied brand. This study provides a new perspective on the mass spectrometry characteristics of trace components of sauce-flavor Baijiu and offers a theoretical foundation for further optimization of the gradients in Baijiu.

14.
Environ Int ; 172: 107796, 2023 02.
Article in English | MEDLINE | ID: mdl-36773562

ABSTRACT

Organic nitrogen (ON) is an important participant in the Earth's N cycle. Previous studies have shown that penguin feces add an abundance of nutrients including N to the soil, significantly changing the eco-environment in ice-free areas in Antarctica. To explore the molecular transformation of ON in penguin guano-affected soil, we collected guano-free weathered soil, modern guano-affected soil from penguin colonies, ancient guano-affected soil from abandoned penguin colonies, and penguin feces from the Ross Sea region, Antarctica, and Fourier transform ion cyclotron mass spectrometry (FT-ICR MS) was used to investigate the chemical composition of water-extractable ON. By comparing the molecular compositions of ON among different samples, we found that the number of ON compounds (>4,000) in weathered soil is minimal, while carboxylic-rich alicyclic-like molecules (CRAM-like) are dominant. Penguin feces adds ON into the soil with > 10,000 CHON, CHONS and CHN compounds, including CRAM-like, lipid-like, aliphatic/ peptide-like molecules and amines in the guano-affected soil. After the input of penguin feces, macromolecules continue to degrade, and other ON compounds tend to be oxidized into relatively stable CRAM-like molecules, this is an important transformation process of ON in guano-affected soils. We conclude the roles of various forms of ON in the N cycle are complex and diverse. Combined with previous studies, ON eventually turns into inorganic N and is lost from the soil. The lost N ultimately returns to the ocean and the food web, thus completing the N cycle. Our study preliminarily reveals the molecular transformation of ON in penguin guano-affected soil and is important for understanding the N cycle in Antarctica.


Subject(s)
Spheniscidae , Humans , Animals , Nitrogen , Antarctic Regions , Soil/chemistry , Amines
15.
Water Res ; 233: 119732, 2023 Apr 15.
Article in English | MEDLINE | ID: mdl-36801578

ABSTRACT

Cold seeps with methane-rich fluids leaking out of the seafloor usually support massive biomass of chemosynthetic organisms and associated fauna. A substantial amount of methane is converted to dissolved inorganic carbon by microbial metabolism, and this process also releases dissolved organic matter (DOM) into pore water. Here, pore water samples from "Haima cold seeps" sediments and the non-seep reference sediments in the northern South China Sea were analyzed for optical properties and molecular compositions of pore water DOM. Our results showed that the relative abundance of protein-like DOM, H/Cwa and molecular lability boundary percentage (MLBL%) in the seep sediments were significantly higher than those in the reference sediments, indicating that more labile DOM related to unsaturated aliphatic compounds is produced in the seep sediments. Spearman's correlation of the fluoresce and molecular data suggested that the humic-like components (C1 and C2) mainly constituted the refractory compounds (CRAM, highly unsaturated and aromatics compounds). In contrast, the protein-like component (C3) had high H/C ratios featuring high degree of DOM lability. The amount of S-containing formulas (CHOS and CHONS) was greatly elevated in the seep sediments, likely caused by abiotic and biotic sulfurization of DOM in the sulfidic environment. Although the abiotic sulfurization was proposed to have a stabilizing effect on organic matter, our results implied that the biotic sulfurization in the cold seep sediments would increase DOM lability. Overall, the labile DOM accumulated in the seep sediments is closely linked to methane oxidation, which not only support heterotrophic communities and but also likely have an impact on carbon and sulfur cycling in the sediments and the ocean.


Subject(s)
Dissolved Organic Matter , Geologic Sediments , Water , Methane/metabolism , China , Sulfur , Carbon
16.
Sci Total Environ ; 857(Pt 1): 159337, 2023 Jan 20.
Article in English | MEDLINE | ID: mdl-36228802

ABSTRACT

Dissolved organic matter (DOM) plays a significant role in the reduction of snow albedo and the acceleration of snowmelt, but its accumulation in snow remains poorly understood. This study investigated the accumulation of DOM in seasonal snow including its accumulation rate, molecular characteristics, and biological and chemical processing. Sixteen snow samples of both fresh and aged snow were collected at one-day interval in Changchun, a typical industrial city in NE China. The snow DOM contents increased linearly with accumulation time at a rate of 30.3 µg L-1 d-1. The optical properties, including fluorescence intensity and optical absorption coefficient, of snowmelt increased exponentially with time owing to the rapid accumulation of terrestrial humic-like fluorophores through snow-soil exchange and deposition of soil-derived substances. Fourier transform-ion cyclotron resonance-mass spectrometry highlighted the properties of DOM at a molecular level, indicating that compounds derived from underlying soil and vascular plants make the largest contribution to DOM. Microbe-derived compounds contribute 35.5 % to the DOM pool. Degrees of saturation and oxidation increase slightly after accumulation, with the impacts of photo- and bio-chemistry on DOM molecules being non-negligible. This study provides a new perspective concerning the accumulation and fate of organic contaminants in snow ecosystems.


Subject(s)
Ecosystem , Snow , Dissolved Organic Matter , Seasons , Soil/chemistry , China , Spectrometry, Fluorescence , Humic Substances/analysis
17.
Rapid Commun Mass Spectrom ; 37(1): e9397, 2023 Jan 15.
Article in English | MEDLINE | ID: mdl-36098176

ABSTRACT

RATIONALE: The development of appropriate analytical screening techniques for pharmaceuticals and personal care products (PPCPs) is the basis for studying the distribution and environmental impact of emerging contaminants (ECs). Mass spectrometry-based screening methods vary with the complexity of the target compounds. It is challenging to balance both positive and negative ion quantification with a low detection limit. To establish a set of experimental methods including extraction, chromatography-separation and mass spectrometry screening is one of the most important topics in PPCP research. This paper describes a universal and efficient qualification and quantification protocol for the simultaneous detection of 34 PPCPs in different environmental samples in a single analytical data acquisition run. METHODS: Thirty-four representative PPCPs, which are widely distributed in the environment with high ecological toxicity and complex chemical structures, were selected as representative target ECs. The extraction of the target PPCPs was achieved using only one solid-phase extraction cartridge without the need to adjust the pH of samples. The enriched samples were detected by LC-MS/MS in both positive and negative ion modes simultaneously. The protocol was evaluated based on the accuracy, precision, detection limits and matrix effects. RESULTS: This method achieved simultaneous detection of PPCPs in both positive and negative ion modes, with a single analytical cycle of 12 min. The observed SPE recoveries were between 40% and 115%. The instrumental detection limits (IDL) varied from 0.01 to 1 pg, and the method detection limits (MDL) were between 0.002 and 3.323 ng/l in different matrices. Most of the PPCPs were subjected to matrix suppression below 30%. The method was successfully applied for quantitative analysis of the PPCPs in different environmental samples, including river samples, wastewater treatment plant (WWTP) samples and soil samples. CONCLUSIONS: This protocol developed a rapid and efficient detection method to simultaneous qualitative and quantitative 34 representative PPCPs in the environment. The IDL ranged from 0.01 to 1 pg and the MDL ranged from 0.002 to 3.323 ng/l in different matrices. The detection limit was one order of magnitude lower compared to previous studies. The protocol also provided a wide application range for different environmental matrices, which permitted the migration and transformation of PPCPs to be explored.


Subject(s)
Cosmetics , Water Pollutants, Chemical , Chromatography, Liquid/methods , Tandem Mass Spectrometry/methods , Water Pollutants, Chemical/analysis , Cosmetics/analysis , Solid Phase Extraction/methods , Pharmaceutical Preparations , Environmental Monitoring/methods
18.
Anal Sci Adv ; 4(1-2): 13-14, 2023 Feb.
Article in English | MEDLINE | ID: mdl-38715580
19.
Rapid Commun Mass Spectrom ; 36(19): e9364, 2022 Oct 15.
Article in English | MEDLINE | ID: mdl-35902538

ABSTRACT

RATIONALE: Fourier transform ion cyclotron resonance mass spectrometry (FT-ICR MS) combined with different ionization techniques provides a powerful means to characterize dissolved organic matter (DOM) at the molecular level. Solid-phase extraction (SPE) is currently the most widely utilized method for extracting the DOM, but one-step elution using methanol does not provide a comprehensive picture of DOM. The development of efficient extraction and enrichment methods as well as characterization techniques from water samples remains a priority for DOM research, which is investigated in this study. METHODS: The DOM was extracted from lake water by SPE using one-step elution (methanol or dichloromethane) and multistep elution (water, methanol, acetone, and dichloromethane). A combination of electrospray ionization (ESI), atmospheric pressure photoionization (APPI), and matrix-free laser desorption ionization (LDI) was utilized for FT-ICR MS analysis in both positive (+) and negative (-) ion modes. RESULTS: The total recovery of the multistep elution was 23.5% higher as compared to the investigated one-step elution procedure (85% vs. 61.6%); however, a comparison of the observed molecular species and the range of diversity under different ionization techniques along with the statistical analyses showed that proper selection of solvent and ionization method was required to explore specific compounds from the sample. CONCLUSIONS: For DOM species containing different heteroatoms, a combination of ESI, APPI, and LDI can offer a comprehensive profile of DOM in aquatic ecosystems. The specific molecular formulae of each ionization technique are characterized as follows: ESI- mode exhibited strong selectivity for lignin-like and tannins-like species with high oxygen content, as well as organosulfates. ESI+ favored lipid species and peptide/protein compounds. Unsaturated and condensed aromatic hydrocarbons with low oxygen were preferably ionized by both APPI and LDI.


Subject(s)
Cyclotrons , Dissolved Organic Matter , Atmospheric Pressure , Ecosystem , Fourier Analysis , Lasers , Mass Spectrometry/methods , Methanol , Methylene Chloride , Oxygen , Solid Phase Extraction/methods , Spectrometry, Mass, Electrospray Ionization/methods , Water
20.
Front Pharmacol ; 13: 906301, 2022.
Article in English | MEDLINE | ID: mdl-35721116

ABSTRACT

In many studies, the extensive and significant anticancer activity of chelerythrine (CHE) was identified, which is the primary natural active compound in four traditional botanical drugs and can be applied as a promising treatment in various solid tumors. So this review aimed to summarize the anticancer capacities and the antitumor mechanism of CHE. The literature searches revolving around CHE have been carried out on PubMed, Web of Science, ScienceDirect, and MEDLINE databases. Increasing evidence indicates that CHE, as a benzophenanthridine alkaloid, exhibits its excellent anticancer activity as CHE can intervene in tumor progression and inhibit tumor growth in multiple ways, such as induction of cancer cell apoptosis, cell cycle arrest, prevention of tumor invasion and metastasis, autophagy-mediated cell death, bind selectively to telomeric G-quadruplex and strongly inhibit the telomerase activity through G-quadruplex stabilization, reactive oxygen species (ROS), mitogen-activated protein kinase (MAPK), and PKC. The role of CHE against diverse types of cancers has been investigated in many studies and has been identified as the main antitumor drug candidate in drug discovery programs. The current complex data suggest the potential value in clinical application and the future direction of CHE as a therapeutic drug in cancer. Furthermore, the limitations and the present problems are also highlighted in this review. Despite the unclearly delineated molecular targets of CHE, extensive research in this area provided continuously fresh data exploitable in the clinic while addressing the present requirement for further studies such as toxicological studies, combination medication, and the development of novel chemical methods or biomaterials to extend the effects of CHE or the development of its derivatives and analogs, contributing to the effective transformation of this underestimated anticancer drug into clinical practice. We believe that this review can provide support for the clinical application of a new anticancer drug in the future.

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