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1.
Environ Sci Technol ; 58(16): 7020-7031, 2024 Apr 23.
Article in English | MEDLINE | ID: mdl-38608167

ABSTRACT

Adjusting the electronic state of noble metal catalysts on a nanoscale is crucial for optimizing the performance of nanocatalysts in many important environmental catalytic reactions, particularly in volatile organic compound (VOC) combustion. This study reports a novel strategy for optimizing Pt catalysts by modifying their electronic structure to enhance the electron density of Pt. The research illustrates the optimal 0.2Pt-0.3W/Fe2O3 heterostructure with atomic-thick WO3 layers as a bulking block to electronically modify supported Pt nanoparticles. Methods such as electron microscopy, X-ray photoelectron spectroscopy, and in situ Fourier transform infrared spectroscopy confirm Pt's electron-enriched state resulting from electron transfer from atomic-thick WO3. Testing for benzene oxidation revealed enhanced low-temperature activity with moderate tungsten incorporation. Kinetic and mechanistic analyses provide insights into how the enriched electron density benefits the activation of oxygen and the adsorption of benzene on Pt sites, thereby facilitating the oxidation reaction. This pioneering work on modifying the electronic structure of supported Pt nanocatalysts establishes an innovative catalyst design approach. The electronic structure-performance-dependent relationships presented in this study assist in the rational design of efficient VOC abatement catalysts, contributing to clean energy and environmental solutions.

2.
Int J Gasteroenterol (N Y) ; 8(1): 5-10, 2024 Jun.
Article in English | MEDLINE | ID: mdl-38487339

ABSTRACT

An estimated 694,550 United States service members were actively deployed to the Persian Gulf from 1990-1991. Many veterans who were deployed developed Persian Gulf War Syndrome along with chronic gastrointestinal symptoms after returning from the Persian Gulf. Our objective in this study was to determine the phenotypic expression of gastrointestinal symptom complexes in previously healthy veterans who had been stationed in the Persian Gulf. One hundred and four consecutive veterans (88 males, 16 females) who had previously been deployed in 1990-91 were evaluated for their bowel habits and gastrointestinal symptoms. A workup was completed to find identifiable causes of their symptoms and all veterans were asked to do a modified version of the Bowel Disease Questionnaire symptom survey. None of the veterans reported gastrointestinal symptoms before deployment. During deployment to the Persian Gulf: 22 veterans (21%) developed irritable bowel syndrome; 17 (16%) developed dyspepsia; 50 (48%) developed diarrhea; 11 (11%) developed bloating; and 4 (4%) developed constipation. The results of the current study suggest that the development of irritable bowel syndrome, dyspepsia, diarrhea, bloating, and constipation is frequently seen in deployed Gulf War Veterans and the gastrointestinal symptoms commonly persist upon returning home. These novel findings are very important for currently deployed veterans who are serving in the Middle East and are at a high risk of developing gastrointestinal disorders.

3.
Biomed Chromatogr ; 38(5): e5835, 2024 May.
Article in English | MEDLINE | ID: mdl-38304995

ABSTRACT

The saponin-enriched extract from Celosiae Semen is a promising resource owing to its lipid-lowering activity. However, triterpenoid saponins are difficult to extract owing to their high molecular weight and strong water solubility. The aim of this paper was to explore an eco-friendly and effective technology of extraction and enrichment of total triterpenoid saponins to obtain high lipid-lowering fractions. Initially, Box-Behnken design experiments were employed to optimize the heat reflux extraction process on the basic of mono-factor experiments. Afterwards, the crude extract was further purified using D-101 resin, and the purification parameters were investigated based on adsorption/desorption experiments and biological activity assay. Under optimal conditions, the purity of the finally obtained total triterpenoid saponins was increased by 7.28-fold. The lipid-lowering activities of the six main triterpenoid saponins were evaluated in HepG2 cells induced by palmitic acid. The results of Oil Red O staining showed that the compounds all exhibited potential lipid-lowering activity. The structure-activity relationship analysis suggested that the oligosaccharide chain at C-28 played an essential role in their lipid-lowering activity and the substituent group at C-23 site also showed important effects. The optimal extraction and purification methods may facilitate the utilization of Celosiae Semen for the industrial production as a functional food and drug.


Subject(s)
Hypolipidemic Agents , Plant Extracts , Saponins , Triterpenes , Saponins/isolation & purification , Saponins/pharmacology , Saponins/chemistry , Humans , Triterpenes/isolation & purification , Triterpenes/chemistry , Triterpenes/pharmacology , Hep G2 Cells , Hypolipidemic Agents/chemistry , Hypolipidemic Agents/pharmacology , Hypolipidemic Agents/isolation & purification , Plant Extracts/chemistry , Plant Extracts/pharmacology , Plant Extracts/isolation & purification , Chromatography, High Pressure Liquid/methods , Structure-Activity Relationship
4.
Sci Total Environ ; 912: 169670, 2024 Feb 20.
Article in English | MEDLINE | ID: mdl-38160830

ABSTRACT

Fulvic acid (FA) is a representative photosensitive dissolved organic matter (DOM) compound that occurs naturally in paddy soils. In this study, the effect of a FA + nitrate treatment (0, 4 and 8 mg/L FA + 20 mmol/L nitrate) on denitrification and As(III) immobilization in flooded paddy soils was assessed under dark and intermittently illuminated conditions (12 h light+12 h dark). The FA input stimulated denitrification in illuminated soils (~100 % of nitrate removal within 6 days) compared to dark conditions (~92 % nitrate removal after 6 days). Meanwhile, As(III) (initial concentration of 0.1 mmol/L) was nearly completely immobilized (~100 %) under illuminated conditions after 4 days for the FA + nitrate treatment compared to 90- 93 % retention in the dark. Denitrification and As immobilization were positively related to the FA dosage in the illuminated assays. The stronger denitrification in illuminated soils was ascribed to denitrifiers harvesting photoelectrons from photosensitive substrates/semiconducting minerals. FA addition also increased the activities of denitrifying enzymes (e.g., NAR, NIR and NOR) and the denitrification electron transport system by nearly 0.6-0.7 and 1.5-1.8 times that of the nitrate-alone treatment under illuminated and dark conditions, thereby fostering stronger denitrification. Upon irradiation, As(III) immobilization was not only stimulated by the interactions with the denitrification pathway whereby As(III) acts as an electron donor for denitrifiers, but was also modulated by Fe(III)/oxidative reactive species-derived photooxidation of As(III). Moreover, the FA + nitrate treatment promoted the enrichment of metal-oxidizing bacteria (e.g., Stenotrophomonas and Acidovorax) that are responsible for nitrate-dependent As(III)/Fe(II) oxidation. The results of this study enhance our understanding of interactions among the biogeochemical cycles of As, Fe, N and C, which are intricately linked by a biophotoelectrochemical pathway in flooded paddy soils.


Subject(s)
Benzopyrans , Denitrification , Nitrates , Nitrates/metabolism , Ferric Compounds , Soil/chemistry , Oxidation-Reduction
5.
Langmuir ; 39(43): 15343-15354, 2023 Oct 31.
Article in English | MEDLINE | ID: mdl-37857276

ABSTRACT

Volatile organic compounds such as benzene are hazardous air pollutants that require effective elimination. Noble metal-based catalysts exhibit high benzene combustion activity, but their prohibitive cost necessitates strategies to enhance utilization efficiency. This study investigates a Pt-Cu alloy catalyst for improved benzene combustion by preferentially exposing Pt active sites through Cu alloying. Aberration-corrected scanning transmission electron microscopy and X-ray spectroscopy characterize the nanoscale distribution and enrichment of Pt on the alloy surface. Kinetic measurements demonstrate substantially enhanced activity compared with Pt catalysts, attributed to increased Pt metallic site exposure rather than alteration of the reaction mechanism. In situ Fourier transform infrared (FTIR) spectroscopy reveals a higher abundance of terrace-like Pt sites in the alloy, beneficial for benzene adsorption. Partial pressure dependence analyses indicate competitive adsorption of benzene and O2, following Langmuir-Hinshelwood kinetics. These findings provide conceptual insights into tuning surface composition in bimetallic catalysts to optimize noble metal efficiency, with broad applicability for sustainable catalytic process advancement.

6.
Materials (Basel) ; 16(9)2023 May 04.
Article in English | MEDLINE | ID: mdl-37176413

ABSTRACT

CO2, as a cheap and abundant renewable C1 resource, can be used to synthesize high value-added chemicals. In this paper, a series of bifunctional metallic niobium complexes were synthesized and their structures were characterized by IR, NMR and elemental analysis. All of these complexes have been proved to be efficient catalysts for the coupling reaction of CO2 and epoxides to obtain cyclic carbonates under solvent- and co-catalyst-free conditions. By using CO2 and propylene oxide as a model reaction, the optimal reaction conditions were systematically screened as: 100 °C, 1 MPa, 2 h, ratio of catalyst to alkylene oxide 1:100. Under the optimal reaction conditions, the bifunctional niobium catalysts can efficiently catalyze the coupling reaction with high yield and excellent selectivity (maximum yield of >99% at high pressure and 96.8% at atmospheric pressure). Moreover, this series of catalysts can also catalyze the coupling reaction at atmospheric pressure and most of them showed high conversion of epoxide. The catalysts have good substrate suitability and are also applicable to a variety of epoxides including diepoxides and good catalytic performances were achieved for producing the corresponding cyclic carbonates in most cases. Furthermore, the catalysts can be easily recovered by simple filtration and reused for at least five times without obvious loss of catalytic activity and selectivity. Kinetic studies were carried out preliminarily for the bifunctional niobium complexes with different halogen ions (3a(Cl-), 3b(Br-), 3c(I-)) and the formation activation energies (Ea) of cyclic carbonates were obtained. The order of apparent activation energy Ea is 3a (96.2 kJ/mol) > 3b (68.2 kJ/mol) > 3c (37.4 kJ/mol). Finally, a possible reaction mechanism is proposed.

7.
Materials (Basel) ; 16(4)2023 Feb 16.
Article in English | MEDLINE | ID: mdl-36837280

ABSTRACT

A series of bifunctional Schiff base metal catalysts (Zn-NPClR, Zn-NPXH, and M-NPClH) with two quaternary ammonium groups were prepared for carbon dioxide (CO2) and epoxide coupling reactions. The effects of the reaction variables on the catalytic activity were systematically investigated, and the optimal reaction conditions (120 °C, 1 MPa CO2, 3 h) were screened. The performances of different metal-centered catalysts were evaluated, and Co-NPClH showed excellent activity. This kind of bifunctional catalyst has a wide range of substrate applicability, excellent stability, and can be reused for more than five runs. A relatively high TOF could reach up to 1416 h-1 with Zn-NPClH as catalyst by adjusting reaction factors. In addition, the kinetic study of the coupling reaction catalyzed by three catalysts (Zn, Co, and Ni) was carried out to obtain the activation energy (Ea) for the formation of cyclic carbonates. Finally, a possible mechanism for this cyclization reaction was proposed.

8.
Insights Imaging ; 14(1): 12, 2023 Jan 16.
Article in English | MEDLINE | ID: mdl-36645541

ABSTRACT

OBJECTIVES: This study aimed to evaluate the feasibility of reduced full-of-view synthetic high-b value diffusion-weighted images (rFOV-syDWIs) in the clinical application of cervical cancer based on image quality and diagnostic efficacy. METHODS: We retrospectively evaluated the data of 35 patients with cervical cancer and 35 healthy volunteers from May to November 2021. All patients and volunteers underwent rFOV-DWI scans, including a 13b-protocol: b = 0, 25, 50, 75, 100, 150, 200, 400, 600, 800, 1000, 1200, and 1500 s/mm2 and a 5b-protocol: b = 0, 100, 400, 800,1500 s/mm2. rFOV-syDWIs with b values of 1200 (rFOV-syDWIb=1200) and 1500 (rFOV-syDWIb=1500) were generated from two different multiple-b-value image datasets using a mono-exponential fitting algorithm. According to homoscedasticity and normality assessed by the Levene's test and Shapiro-Wilk test, the inter-modality differences of quantitative measurements were, respectively, examined by Wilcoxon signed-rank test or paired t test and the inter-group differences of ADC values were examined by independent t test or Mann-Whitney U test. RESULTS: A higher inter-reader agreement between SNRs and CNRs was found in 13b-protocol and 5b-protocol rFOV-syDWIb=1200/1500 compared to 13b-protocol rFOV-sDWIb=1200/1500 (p < 0.05). AUC of 5b-protocol syADCmean,b=1200/1500 and syADCminimum,b=1200/1500 was equal or higher than that of 13b-protocol sADCmean,b=1200/1500 and sADCminimum,b=1200/1500. CONCLUSIONS: rFOV-syDWIs provide better lesion clarity and higher image quality than rFOV-sDWIs. 5b-protocol rFOV-syDWIs shorten scan time, and synthetic ADCs offer reliable diagnosis value as scanned 13b-protocol DWIs.

9.
Gastroenterology ; 164(4): 630-641.e34, 2023 04.
Article in English | MEDLINE | ID: mdl-36623778

ABSTRACT

BACKGROUND & AIMS: The etiology of abdominal pain in postinfectious, diarrhea-predominant irritable bowel syndrome (PI-IBS-D) is unknown, and few treatment options exist. Catechol-O-methyltransferase (COMT), an enzyme that inactivates and degrades biologically active catecholamines, plays an important role in numerous physiologic processes, including modulation of pain perception. Our objective was to determine the mechanism(s) of how decreased colonic COMT in PI-IBS-D patients contributes to the chronic abdominal pain phenotype after enteric infections. METHODS: Colon neurons, epithelial cells, and macrophages were procured with laser capture microdissection from PI-IBS-D patients to evaluate cell-specific colonic COMT, microRNA-155 (miR-155), and tumor necrosis factor (TNF) α expression levels compared to recovered patients (infection cleared: did not develop PI-IBS-D) and control individuals. COMT-/-, colon-specific COMT-/-, and miR-155-/- mice and human colonoids were used to model phenotypic expression of COMT in PI-IBS-D patients and to investigate signaling pathways linking abdominal pain. Citrobacter rodentium and trinitrobenzene sulfonic acid animal models were used to model postinflammatory changes seen in PI-IBS-D patients. RESULTS: Colonic COMT levels were significantly decreased and correlated with increased visual analog scale abdominal pain ratings in PI-IBS-D patients compared to recovered patients and control individuals. Colonic miR-155 and TNF-α were increased in PI-IBS-D patients with diminished colonic COMT. COMT-/- mice had significantly increased expression of miR-155 and TNF-α in both colon tissues and dorsal root ganglia. Introduction of cV1q antibody (anti-TNF-α) into mice reversed visceral hypersensitivity after C rodentium and trinitrobenzene sulfonic acid. CONCLUSIONS: Decreased colonic COMT in PI-IBS-D patients drives abdominal pain phenotypes via the COMT/miR-155/TNF-α axis. These important findings will allow new treatment paradigms and more targeted and personalized medicine approaches for gastrointestinal disorders after enteric infections.


Subject(s)
Irritable Bowel Syndrome , MicroRNAs , Humans , Mice , Animals , Irritable Bowel Syndrome/metabolism , Tumor Necrosis Factor-alpha/metabolism , Catechol O-Methyltransferase/genetics , Catechol O-Methyltransferase/metabolism , Nociception , Tumor Necrosis Factor Inhibitors , Colon/metabolism , Abdominal Pain/genetics , Abdominal Pain/metabolism , MicroRNAs/genetics , MicroRNAs/metabolism , Trinitrobenzenes/metabolism , Sulfonic Acids/metabolism
10.
J Investig Med ; 71(1): 7-10, 2023 01.
Article in English | MEDLINE | ID: mdl-35798472

ABSTRACT

Over 25% of veterans with Gulf War illness developed chronic gastrointestinal (GI) symptoms of unknown etiology after they returned from deployment to the Persian Gulf. To determine the prevalence of delayed gastric emptying and its association with autonomic dysfunction in returning Gulf War (GW) veterans with chronic GI symptoms, we prospectively studied 35 veterans who were deployed to the Persian Gulf and developed chronic nausea, vomiting, postprandial abdominal pain, and bloating during their tour of duty and 15 asymptomatic controls. All veterans underwent 5 standardized cardiovascular tests to assess autonomic function. Each test was scored from 0 (normal) to 5 (severe disease) and the mean was calculated. A composite score >1.5 was considered abnormal, with 5 representing severe autonomic dysfunction. A standardized gastric emptying test with a solid phase was performed in each veteran. A gastric retention of >50% at 100 minutes was considered abnormal. The composite autonomic score was 3.7 in veterans with GI symptoms (vs 1.3 in controls) (p<0.01). The mean solid phase retention at 100 minutes was 72.6% in the symptomatic veterans versus 24.6% in controls (p<0.001). Our results suggest that autonomic dysfunction and delayed gastric emptying are common in returning GW veterans with GI symptoms. Autonomic dysfunction was positively correlated with the severity of delayed gastric emptying and may account for the GI symptoms of nausea, vomiting, postprandial abdominal pain, and bloating. These new findings are important for an increasing number of veterans who are serving in the Persian Gulf and are at a high risk of developing GI disorders while deployed.


Subject(s)
Autonomic Nervous System Diseases , Gastrointestinal Diseases , Gastroparesis , Veterans , Humans , Abdominal Pain/epidemiology , Gastrointestinal Diseases/epidemiology , Gastroparesis/epidemiology , Gulf War , Nausea/epidemiology , Veterans/statistics & numerical data , Vomiting/epidemiology , Autonomic Nervous System Diseases/epidemiology , Chronic Disease , Prospective Studies , Case-Control Studies
11.
Molecules ; 27(17)2022 Aug 25.
Article in English | MEDLINE | ID: mdl-36080196

ABSTRACT

Transient receptor potential vanilloid 1 (TRPV1) is a non-selective cation channel, predominantly expressed in a subset of peripheral sensory neurons for pain signaling. Topical application of agonist capsaicin for desensitizing TRPV1 currents has been approved for relief of chronic pain. However, the potent TRPV1 capsaicin is not ingestible and even topical capsaicin causes common side effects such as skin irritation, swelling, erythema and pruritus, suggesting that a mild TRPV1 agonist might be helpful for reducing side effects while reliving pain. In this study, we reported on a partial and selective TRPV1 agonist 4-(5-chloropyridin-2-yl)-N-(1H-indazol-6-yl)piperazine-1-carboxamide named CPIPC that was modified based on targeting the residue Arg557, important for conversion between the channel antagonism and agonism. Whole-cell patch clamp recordings indicated a concentration-dependent activation of TRPV1 currents by CPIPC with an EC50 of 1.56 ± 0.13 µM. The maximum efficacy of CPIPC (30 µM) was about 60% of saturated capsaicin (10 µM). Repetitive additions of CPIPC caused TRPV1 current desensitization in both TRPV1-expressing HEK293 cells and dorsal root ganglion (DRG) sensory neurons. Oral administration of CPIPC dose-dependently alleviated inflammatory pain in mice. Further site-directed mutagenesis combined with molecular docking revealed that residue Arg557 is critical for TRPV1 activation by CPIPC. Taken together, we identified a novel partial and selective TRPV1 agonist CPIPC that exhibits antinociceptive activity in mice.


Subject(s)
Capsaicin , TRPV Cation Channels , Animals , Capsaicin/pharmacology , Capsaicin/therapeutic use , Ganglia, Spinal , HEK293 Cells , Humans , Mice , Molecular Docking Simulation , Pain/drug therapy , Sensory Receptor Cells , TRPV Cation Channels/agonists
12.
Exp Ther Med ; 24(4): 627, 2022 Oct.
Article in English | MEDLINE | ID: mdl-36160896

ABSTRACT

Long non-coding RNAs (lncRNAs) have been confirmed to be connected with tumor proliferation, apoptosis, metastasis and recurrence. Previous studies have indicated that lncRNA calcium voltage-gated channel subunit α1 G (CACNA1G)-antisense 1 (AS1) can function as a pro-oncogene in several types of cancer. However, the specific role and mechanism of CACNA1G-AS1 have not been fully elucidated in human diffuse large B cell lymphoma (DLBCL). In the present study, CACNA1G-AS1 expression was verified in DLBCL tissues and cells by reverse transcription-quantitative PCR, and the relationship between CACNA1G-AS1 and microRNA (miR)-3160-5p was confirmed using luciferase reporter assays. After CACNA1G-AS1-knockdown and miR-3160-5p-overexpression, MTT, colony formation and flow cytometry assays were conducted to assess the changes in the cytotoxicity and apoptosis of OCI-Ly10 and SUDHL-4 cells. In addition, in vivo experiments were performed to determine the impact of CACNA1G-AS1-knockdown on tumor growth and apoptosis. It was revealed that CACNA1G-AS1 was highly expressed in DLBCL tissues and cells and that expression of CACNA1G-AS1 was associated with the clinical stage of DLBCL. Functionally, CACNA1G-AS1-knockdown was demonstrated to increase cytotoxicity and expedite apoptosis in DLBCL cells in vitro and in vivo. In addition, CACNA1G-AS1 could downregulate miR-3160-5p by targeting binding in DLBCL cells. Overexpression of miR-3160-5p had the same effects on the cytotoxicity and apoptosis of DLBCL cells as CACNA1G-AS1-knockdown. Overall, the present study revealed that CACNA1G-AS1-knockdown and miR-3160-5p-overexpression could prevent DLBCL carcinogenesis, which might provide novel therapeutic targets for DLBCL.

13.
J Med Chem ; 65(17): 11658-11678, 2022 09 08.
Article in English | MEDLINE | ID: mdl-36008373

ABSTRACT

Transient receptor potential vanilloid 1 (TRPV1) is a promising target for developing antinociceptive agents. Here, we report the synthesis of N-indazole-4-aryl piperazine carboxamide analogues as TRPV1 modulators. The structure-activity relationship (SAR) reveals that substituting indazole at the 5-/6-position leads to TRPV1 agonism, whereas the 4- and 7-positions of indazole obtain mild antagonism and loss of activity, respectively. The whole-cell clamp patch assay shows that 28 is a potent and selective TRPV1 agonist and it relieves inflammatory and thermal pain by desensitizing the native TRPV1 current in the dorsal root ganglion (DRG) in mice. Additionally, site-directed mutagenesis combined with molecular docking shows an important hydrogen interaction between Arg557 and the indazole of 28. Taken together, our findings provide insight into TRPV1 agonism-antagonism conversion based on the interaction between indazole and Arg557, which provides a strategy to obtain new TRPV1 agonists by structural modification of antagonists. Compound 28 may be used as a lead compound for further optimization.


Subject(s)
Indazoles , TRPV Cation Channels , Analgesics/pharmacology , Animals , Capsaicin , Ganglia, Spinal , Indazoles/pharmacology , Mice , Molecular Docking Simulation
14.
Neurogastroenterol Motil ; 34(9): e14443, 2022 09.
Article in English | MEDLINE | ID: mdl-35950237

ABSTRACT

Epigenetics is a process that alters gene activity or phenotype without any changes in the underlying DNA sequence or genotype. These biological changes may have deleterious effects and can lead to various human diseases. Ongoing research is continuing to illuminate the role of epigenetics in a variety of pathophysiologic processes. Several categories of epigenetic mechanisms have been studied including chromatin remodeling, DNA methylation, histone modification, and non-coding RNA mechanisms. These epigenetic changes can have a long-term effect on gene expression without any underlying changes in the DNA sequences. The underlying pathophysiology of disorders of brain-gut interaction and stress-induced visceral pain are not fully understood and the role of epigenetic mechanisms in these disorders are starting to be better understood. Current work is underway to determine how epigenetics plays a role in the neurobiology of patients with chronic visceral pain and heightened visceral nociception. More recently, both animal models and human studies have shown how epigenetic regulation modulates stress-induced visceral pain. While much more work is needed to fully delineate the mechanistic role of epigenetics in the neurobiology of chronic visceral nociception, the current study by Louwies et al., in Neurogastroenterology and Motility provides additional evidence supporting the involvement of epigenetic alterations in the central nucleus of the amygdala in stress-induced visceral hypersensitivity in rodents.


Subject(s)
Visceral Pain , Amygdala , Animals , DNA Methylation , Epigenesis, Genetic , Humans , Nociception
16.
Chem Commun (Camb) ; 58(23): 3791-3794, 2022 Mar 18.
Article in English | MEDLINE | ID: mdl-35230378

ABSTRACT

A series of specific and potent fluorescent ligands were developed for labelling and visualizing Kv7.2/7.3 based molecular rotation restriction. Probes 21b and 24a were found to be safe and convenient tools to detect and visualize Kv7.2/7.3 in live cells and mouse brain tissue.


Subject(s)
Brain , Fluorescent Dyes , Animals , Brain/diagnostic imaging , Ligands , Mice
17.
Org Lett ; 24(8): 1610-1615, 2022 03 04.
Article in English | MEDLINE | ID: mdl-35179033

ABSTRACT

Five unprecedented chromone derivatives involving a 6/6/5/5/5/6 hexacyclic scaffold (1, 2), 6/6/5/6/6/6/6 heptacyclic scaffold (3), and 6/6/6/5/5/6 hexacyclic scaffold (4, 5) were obtained from the fungus Aspergillus deflectus NCC0415. Their structures were identified using comprehensive spectroscopic analysis, single-crystal X-ray diffraction, and electronic circular dichroism calculations. Except for 3, the other compounds, especially the 6/6/6/5/5/6 hexacyclic derivatives (4 and 5), exhibited potent inosine-5'-monophosphate dehydrogenase (IMPDH) inhibitory activities.


Subject(s)
Aspergillus
18.
Sci Total Environ ; 807(Pt 3): 151040, 2022 Feb 10.
Article in English | MEDLINE | ID: mdl-34673055

ABSTRACT

The extensive use of antibiotics for treating humans, animals, and plants has resulted in the contamination of aquatic environments, posing a potential threat to public health and aquatic life; hence, this topic is of great concern worldwide. Lakes are considered to be antibiotic-rich reservoirs because many of the antibiotics discharged from rivers enter lakes. Chaohu Lake is one of the top five freshwater lakes in China. This study aims to provide a current evaluation of the antibiotics present in the surface water of the Chaohu Lake basin. To this end, the occurrences of 18 antibiotics categorized into 5 different groups were investigated in the study area, and the impact of inflowing rivers on their distribution was assessed. The results showed that the concentrations of 14 antibiotics in water samples ranged from 0 to 892 ng/L, and that antibiotics were detected at most sampling sites. Among them, the Nanfeihe and Shiwulihe rivers, which are close to the city, contributed the most to antibiotic pollution, indicating the widespread occurrence of antibiotics in the study area. A risk assessment based on the risk quotient method indicated that ofloxacin, ciprofloxacin, sulfamethoxazole, erythromycin, and norfloxacin in the lake water posed a high ecological risk to algae, while sulfamethazine posed a high risk to plants (RQ >1).


Subject(s)
Anti-Bacterial Agents , Lakes , China , Humans , Risk Assessment , Water
19.
Materials (Basel) ; 16(1)2022 Dec 21.
Article in English | MEDLINE | ID: mdl-36614390

ABSTRACT

Ammonium, imidazole, or pyridinium functionalized ß-cyclodextrins (ß-CDs) were used as efficient one-component bifunctional catalysts for the coupling reaction of carbon dioxide (CO2) and epoxide without the addition of solvent and metal. The influence of different catalysts and reaction parameters on the catalytic performance were examined in detail. Under optimal conditions, Im-CD1-I catalysts functionalized with imidazole groups were able to convert various epoxides into target products with high selectivity and good conversion rates. The one-component bifunctional catalysts can also be recovered easily by filtration and reused at least for five times with only slight decrease in catalytic performance. Finally, a possible process for hydroxyl group-assisted ring-opening of epoxide and functionalized group- induced activation of CO2 was presented.

20.
Article in Chinese | WPRIM (Western Pacific) | ID: wpr-923363

ABSTRACT

Objective@# To investigate the effects of over expression and low expression of antisense transcripts of circular RNA cerebellar degeneration associated protein 1 (CDR1as) in Balb/C mouse bone marrow mesenchymal stem cells (BMSCs) on factors related to osteogenesis and angiogenesis.@*Methods@#BMSCs were cultured and identified in vitro. The lentiviral (LV) vector containing the overexpressed and silenced circRNA CDR1as genes and the control lentivirus were respectively transfected into mouse BMSCs, and stable cell lines were screened. The cells were divided into the circRNACDR1as over expression group and the over expression control group, and the CircRNACDR1as low expression group and the low expression control group. The components were stained with Alizarin Red S and alkaline phosphatase after 14 and 21 days of osteoinduction; qRT-PCR was used to detect the target genes circRNA CDR1as, osteogenic differentiation markers alkaline phosphatase (ALP), runt- related transcription factor 2 (RUNX2), osteocalcin (OCN), osteopontin (OPN), osterix(Osx), collagen I (COL-1), and the mRNA expression levels of vascular endothelial grown factor (VEGF) and angiogenin-1 (Ang-1). @*Results@# The results of alizarin red staining and alkaline phosphatase staining showed that the extracellular matrix calcium precipitation and ALP staining area of the over expression experimental group was greater than its control group, and those of the low expression experimental group was less than its control group. As the number of days of osteogenic induction increased, the calcium precipitation and ALP staining in each group also increased. RT-PCR results showed that the mRNA expression levels of circRNA CDR1as, ALP, RUNX2, OCN, OPN, OSX, COL-1, VEGF and Ang-1 in the over expression experimental group BMSCs were significantly increased (P<0.001). In the low expression experimental group, the mRNA expression levels of circRNA CDR1as, ALP, RUNX2, OCN, OPN, OSX, COL-1, VEGF and Ang-1 in BMSCs were significantly reduced (P<0.001). @*Conclusion@# Over expression of the circRNA CDR1as gene promotes the osteogenic differentiation and angiogenesis of BMSCs. Low expression of the circRNA CDR1as gene inhibits the osteogenic differentiation and angiogenesis of BMSCs.

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