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1.
Environ Sci Technol ; 57(48): 19912-19920, 2023 Dec 05.
Artigo em Inglês | MEDLINE | ID: mdl-37962431

RESUMO

Chloroform (CF) and dichloromethane (DCM) contaminate groundwater sites around the world but can be cleaned up through bioremediation. Although several strains of Dehalobacter restrictus can reduce CF to DCM and multiple Peptococcaceae can ferment DCM, these processes cannot typically happen simultaneously due to CF sensitivity in the known DCM-degraders or electron donor competition. Here, we present a mixed microbial culture that can simultaneously metabolize CF and DCM and create an additional enrichment culture fed only DCM. Through genus-specific quantitative polymerase chain reaction, we find that Dehalobacter grows while either CF alone or DCM alone is converted, indicating its involvement in both metabolic steps. Additionally, the culture was maintained for over 1400 days without the addition of an exogenous electron donor, and through electron balance calculations, we show that DCM metabolism would produce sufficient reducing equivalents (likely hydrogen) for CF respiration. Together, these results suggest intraspecies electron transfer could occur to continually reduce CF in the culture. Minimizing the addition of electron donor reduces the cost of bioremediation, and "self-feeding" could prolong bioremediation activity long after donor addition ends. Overall, understanding this mechanism informs strategies for culture maintenance and scale-up and benefits contaminated sites where the culture is employed for remediation worldwide.


Assuntos
Clorofórmio , Cloreto de Metileno , Clorofórmio/metabolismo , Cloreto de Metileno/metabolismo , Biodegradação Ambiental , Halogenação , Peptococcaceae/metabolismo
2.
Spectrochim Acta A Mol Biomol Spectrosc ; 303: 123139, 2023 Dec 15.
Artigo em Inglês | MEDLINE | ID: mdl-37463552

RESUMO

A simple near-infrared (NIR) spectroscopic scheme enabling direct measurement of organic phase extracted from human bile with no spectral interference from the extraction solvent was demonstrated for identification of gallbladder (GB) cancer. This scheme is used to recognize the different lipid contents in bile samples from GB cancer patients using NIR spectroscopy for disease identification. To this end, the extraction solvent should provide an absorption-free NIR region to observe peaks of related metabolite. For this purpose, deuterated chloroform (CDCl3) is uniquely suited as an extraction medium because it has few absorption peaks in the 4380-4100 cm-1 range, where intense peaks for lipids and cholesterol are located. This exploratory study used 37 bile samples (obtained from five normal subjects and nine GB polyp, 11 gallstone, six hepatocellular carcinoma (HCC), and six GB cancer patients). The transmission NIR spectra of the organic phases extracted using CDCl3 in a commercial glass vial were directly measured. The peak intensities of the GB cancer samples were lower than those of the other samples, and the differences were statistically significant, with a confidence interval greater than 99.0%. The lower lipid and cholesterol contents in the organic phases of the GB cancer samples were effectively identified in the corresponding NIR spectra. Therefore, the proposed NIR scheme is simpler and faster than the previous infrared (IR) measurement approach that requires solvent drying to highlight the buried metabolite peaks under a solvent absorption band.


Assuntos
Carcinoma Hepatocelular , Neoplasias da Vesícula Biliar , Neoplasias Hepáticas , Humanos , Bile/química , Bile/metabolismo , Neoplasias da Vesícula Biliar/diagnóstico , Neoplasias da Vesícula Biliar/metabolismo , Clorofórmio/metabolismo , Neoplasias Hepáticas/diagnóstico , Neoplasias Hepáticas/metabolismo , Colesterol/análise , Solventes
3.
Reprod Sci ; 30(11): 3359-3371, 2023 11.
Artigo em Inglês | MEDLINE | ID: mdl-37286756

RESUMO

Infertility affects 15% of global population. This study was designed to search out the most effective dose of chloroform fraction of hydro-ethanolic extract of Hygrophila auriculata seed to ameliorate cyproterone acetate (CPA)-treated male subfertility. The rats were made subfertile by CPA at the dose of 2.5 mg/100gm body weight for 45 days. The male subfertility represented by low sperm concentration, less motile, less viable, and less hypo osmotic tail swelled spermatozoa in CPA-treated group. Serum LH, FSH, and testosterone levels were significantly decreased in CPA-treated group in respect to control. Androgenic key enzyme Δ5,3ß-HSD, 17ß-HSD activities and gene expression pattern were also decreased significantly in respect to control. These antispermatogenic and antiandrogenic activities of CPA were significantly recovered after the treatment of Hygrophila auriculata at the dose of 2.5 mg, 5mg, and 10 mg/100gm body weight. CPA also generate oxidative free radical that indicated by altered catalase, superoxide dismutase, and peroxidase activities and protein expression pattern along with conjugated diene and thiobarbituric acid reactive substance levels in testis. Expression pattern of Bax and Bcl2 genes were deviated from control after CPA treatment. Significant diminution of body weight, organo-somatic indices, and SGOT, SGPT activities were observed in CPA-treated group. All these biomarkers significantly recovered towards control after the treatment of Hygrophila auriculata at different doses. More significant recovery was observed in 5 mg and 10 mg of chloroform fraction-treated group and 5 mg dose, i.e., the minimum therapeutic dose to recover the CPA-induced subfertility.


Assuntos
Acanthaceae , Infertilidade Masculina , Humanos , Masculino , Ratos , Animais , Acetato de Ciproterona/efeitos adversos , Acetato de Ciproterona/metabolismo , Testosterona , Clorofórmio/efeitos adversos , Clorofórmio/metabolismo , Sementes , Testículo/metabolismo , Infertilidade Masculina/metabolismo , Peso Corporal , Estresse Oxidativo
4.
Braz J Microbiol ; 54(2): 1103-1113, 2023 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-36807883

RESUMO

During storage, infected potato tubers by Fusarium species leads to significant losses. Searching natural-based alternatives to chemical fungicides for the control of tuber dry rot pathogens is becoming essential. Nine Aspergillus spp. (A. niger, A. terreus, A. flavus, and Aspergillus sp.) isolates, recovered from soil and compost samples, were explored and evaluated for their ability to suppress Fusarium sambucinum the main causal agent of potato tuber dry rot disease in Tunisia. All conidial suspensions of Aspergillus spp. tested and their cell-free culture filtrates had significantly inhibited the in vitro pathogen growth by 18.5 to 35.9% and by 9 to 69% compared to control, respectively. A. niger CH12 cell-free filtrate was the most active against F. sambucinum at the three concentration tested (10, 15, and 20% v v-1). Chloroform and ethyl acetate extracts from four Aspergillus spp., tested at 5% v v-1, had limited F. sambucinum mycelial growth by 34-60% and 38-66%, respectively, compared to control, with A. niger CH12 ethyl extract being the most active. Tested on potato tubers inoculated with F. sambucinum, all tested Aspergillus spp. isolates, their cell-free filtrates and organic extracts had significantly decreased the external diameter of dry rot lesion compared to pathogen-inoculated and untreated control tubers. For the rot penetration, all Aspergillus spp. isolates, their organic extracts and only filtrates from A. niger CH12 and MC2 isolates had significantly limited dry rot severity compared to pathogen-inoculated and untreated control. The highest reductions in the external diameter of dry rot lesion (76.6 and 64.1%) and the average rot penetration (77.1 and 65.1%) were achieved using chloroform and ethyl acetate extracts from A. niger CH12, respectively. These results clearly demonstrated the presence of bioactive compounds in Aspergillus spp. that can be extracted and explored as an eco-friendly alternative for the control of the target pathogen.


Assuntos
Compostagem , Fusarium , Solanum tuberosum , Solo , Solanum tuberosum/microbiologia , Clorofórmio/metabolismo , Aspergillus
5.
Chem Biodivers ; 20(3): e202200755, 2023 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-36722706

RESUMO

Fraxinus xanthoxyloides is a perennial shrub belonging to family Oleaceae, traditionally used for malaria, jaundice, pneumonia, inflammation, and rheumatism. Our study is aimed to assess the total phenolics (TPC), flavonoids (TFC), terpenoids contents (TTC) and antioxidant profiling of F. xanthoxyloides methanol bark extract (FXBM) and its fractions, hexane, chloroform, ethyl acetate and aqueous, along with high-performance liquid chromatography with diode-array detection (HPLC-DAD). Further, the antioxidant and pulmonary protective potential was explored against carbon tetrachloride (CCl4 )-induced CCl4-induced pulmonary tissue damage in rats. The highest TPC, TFC and TTC were found in FXBM (133.29±4.19 mg/g), ethyl acetate fraction (279.55±10.35 mg/g), and chloroform fraction (0.79±0.06 mg/g), respectively. The most potent antioxidant capacity was depicted by FXBM (29.21±2.40 µg/mg) and ethyl acetate fraction (91.16±5.51 µg/mg). The HPLC-DAD analysis revealed the predominance of gallic, chlorogenic, vanillic and ferulic acid in FXBM. The administration of CCl4 induced oxidative stress, suppressed antioxidant enzymes' activities including catalase, peroxidase, superoxide dismutase, glutathione peroxidase, glutathione-S-transferase, and glutathione reductase. Further, it increased thiobarbituric acid reactive substances (TBARS) and H2 O2 levels, induced DNA injuries and reduced the total protein and glutathione content in lung tissues. The treatment of rats with FXBM restored these biochemical parameters to the normal level. Moreover, the histopathological studies of lung tissues demonstrated that FXBM protected rats' lung tissues from oxidative damage restoring normal lung functions. Thus, F. xanthoxyloides bark extract is recommended as adjuvant therapy as protective agent for patients with lung disorders.


Assuntos
Antioxidantes , Fraxinus , Lesão Pulmonar , Extratos Vegetais , Animais , Ratos , Antioxidantes/química , Clorofórmio/metabolismo , Clorofórmio/toxicidade , Fraxinus/química , Fraxinus/metabolismo , Glutationa/metabolismo , Peroxidação de Lipídeos , Fígado/metabolismo , Pulmão/metabolismo , Estresse Oxidativo , Casca de Planta/química , Casca de Planta/metabolismo , Extratos Vegetais/química , Extratos Vegetais/farmacologia , Extratos Vegetais/uso terapêutico , Ratos Sprague-Dawley , Lesão Pulmonar/induzido quimicamente , Lesão Pulmonar/tratamento farmacológico
6.
Biomed Pharmacother ; 154: 113633, 2022 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-36063647

RESUMO

There are 27 million cases of Salmonella Typhimurium (STM) reported worldwide annually, which have resulted in 217,000 deaths to date. Thus, there is an urgent requirement to develop novel antibacterial agents to target the multidrug-resistant strains of STM. We evaluated the inhibitory effect of the chloroform extracts of Atractylodes chinensis (Ac-CE) on the virulence of STM in vitro and develop it as a potential antibacterial agent. First, we determined the in vitro effects of Ac-CE on STM biofilm formation, and swimming, swarming, and adhesion to mucin. Further, we evaluated the effect of Ac-CE on the adhesion and invasion of STM at the gene level. Lastly, we evaluated the inhibitory effect of Ac-CE on STM infectivity at the cellular level. Ac-CE could attenuate both the adhesion and invasion abilities of STM in vitro. At the gene level, it could inhibit the expression of flagella, pilus, biofilm, SPI-1, and SPI-2 genes, which are related to the adhesion and invasion ability of STM in cells. Ac-CE significantly downregulated the expression of inflammatory cytokines and the TLR4/MyD88/NF-κB pathway in an STM infection cell model. It also significantly recovered the expression of intestinal barrier-related genes and proteins in intestinal cells that are damaged during STM infection. Ac-CE is effective as an antivirulence agent in alleviating STM infection. Although the main components of Ac-CE were analyzed.We have not demonstrated the antivirulence effect of the active ingredients in Ac-CE. And the antivirulence effect of Ac-CE and its active ingredients warrant further in vivo studies.


Assuntos
Atractylodes , Salmonella typhimurium , Antibacterianos/metabolismo , Antibacterianos/farmacologia , Atractylodes/metabolismo , Clorofórmio/metabolismo , Clorofórmio/farmacologia , NF-kappa B/metabolismo , Virulência
7.
J Sci Food Agric ; 102(15): 7030-7038, 2022 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-35689485

RESUMO

BACKGROUND: Caragana ambigua has been the part of the dietary routines of the regional people in south-west Pakistan and has traditionally been used for the treatment of diabetes there. There is an increased production of reactive oxygen species in diabetics, leading to gastrointestinal disorders. Natural antioxidants exhibit gastroprotective effects owing to their free-radical scavenging action. C. ambigua possesses appreciable phenolic and flavonoid content; thus, it has the potential to protect against gastrointestinal disorders (e.g. gastric ulcer). RESULTS: This study reports the anti-ulcer potential of C. ambigua. Four different fractions (chloroform, ethyl acetate, butanol, and aqueous) of plant were compared against omeprazole. Ulcer index, ulcer inhibition percentage, gastric pH and volume, total acidity, gastric protein, gastric wall mucus, and histopathology of gastric walls of rats were assessed. All fractions exhibited a reduction in ulcer index and promotion of percentage of ulcer inhibition compared with the ulcer control group. Furthermore, the fractions revealed a significant (P < 0.001) diminution in gastric volume and total acidity with an increase in pH. Among the fractions investigated, the chloroform fraction unveiled the most promising anti-ulcer activity, which is comparable to omeprazole. Liquid chromatography-tandem mass spectrometry screening of fractions revealed the presence of formononetin and biochanin A (isoflavones reported to have anti-ulcer properties) in the chloroform fraction. CONCLUSION: This study establishes that C. ambigua possesses significant potential in reducing gastric ulcer progression. Formononetin and biochanin A are chiefly responsible for the stated bioactivity due to the fact that these compounds were solely present in the chloroform fraction. © 2022 The Authors. Journal of The Science of Food and Agriculture published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry.


Assuntos
Antiulcerosos , Caragana , Úlcera Gástrica , Ratos , Animais , Úlcera Gástrica/induzido quimicamente , Etanol/metabolismo , Antiulcerosos/farmacologia , Clorofórmio/efeitos adversos , Clorofórmio/metabolismo , Cromatografia Líquida , Espectrometria de Massas em Tandem , Extratos Vegetais/química , Mucosa Gástrica/metabolismo , Genisteína/metabolismo , Antioxidantes/química , Omeprazol/efeitos adversos
8.
Oxid Med Cell Longev ; 2022: 8802178, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-36624877

RESUMO

Plants are a significant source for the development of new phytomedicines due to their great clinical benefits, efficiency, cost-effectiveness, fewer side effects, and more affordable therapies. Numerous plants used in traditional treatments, such as Cotinus coggygria Scop., have been effective in the treatment of diabetes mellitus (DM). Therefore, the study is aimed at assessing the phytochemical, antioxidant, and antidiabetic properties of C. coggygria. The hypoglycemic and hypolipidemic activity was evaluated in Swiss male Albino mice by administering an oral dose of 150-250 mg/kg of C. coggygria extracts in alloxan-induced diabetic mice for 15 days. The antioxidant activity and phytochemical composition of the extracts were assessed by using α, α diphenyl-ß-picrylhydrazyl (DPPH) and hydrogen peroxide scavenging assays and through standard chemical procedures. The effects of extracts on blood glucose, body weight, lipid profile, and biochemical parameters like total cholesterol (TC), triglyceride (TG), low-density lipids (LDL), high-density lipids (HDL), plasma insulin, liver glycogen, aspartate aminotransferase (AST), alanine aminotransferase (ALT), alkaline phosphatase (ALP), urea, and creatinine were determined according to standard procedures. The activities of antioxidant enzymes such as superoxide-dismutase (SOD), peroxidase (POD), and catalase (CAT) were also analyzed spectrophotometrically. The hypoglycemic and hypolipidemic effects with chloroform extracts of 250 mg/kg were found significant in the treatment of diabetes in alloxanised mice compared to the diabetic group. The haematological parameters such as TC, TG, HDL, LDL, creatinine, urea, AST, ALT, and ALP were significantly improved (p < 0.01) by the chloroform extract of 250 mg/kg compared to the diabetic group. Treatment for 15 days showed significant elevation (p < 0.01) of antioxidant enzymes. Fourier-transform infrared spectroscopic (FTIR) and gas chromatography-mass spectrometry (GC-MS), column chromatography (CC), and nuclear magnetic resonance (NMR) analyses tentatively identified different phytoconstitutents and metabolites in C. coggygria leaves, which have been reported to possess antihyperglycemic properties. In conclusion, the chloroform extract of 250 mg/kg of C. coggygria possesses significant hypoglycemic and hypolipidemic potential which may prove the claimed use of the plant in amelioration of diabetes and associated complications in folkloric medicine. Additional studies are required for the purification, characterization, and structural elucidation of bioactive compounds.


Assuntos
Anacardiaceae , Diabetes Mellitus Experimental , Camundongos , Animais , Antioxidantes/farmacologia , Antioxidantes/uso terapêutico , Antioxidantes/química , Aloxano/efeitos adversos , Diabetes Mellitus Experimental/metabolismo , Clorofórmio/metabolismo , Clorofórmio/farmacologia , Clorofórmio/uso terapêutico , Creatinina/metabolismo , Extratos Vegetais/farmacologia , Extratos Vegetais/uso terapêutico , Extratos Vegetais/química , Hipolipemiantes/farmacologia , Hipolipemiantes/uso terapêutico , Hipoglicemiantes/farmacologia , Hipoglicemiantes/uso terapêutico , Triglicerídeos , Glicemia/metabolismo , Anacardiaceae/metabolismo , Fígado/metabolismo
9.
Appl Environ Microbiol ; 88(4): e0197021, 2022 02 22.
Artigo em Inglês | MEDLINE | ID: mdl-34936839

RESUMO

Chloroform (CF) and dichloromethane (DCM) are among the more commonly identified chlorinated aliphatic compounds found in contaminated soil and groundwater. Complete dechlorination of CF has been reported under anaerobic conditions by microbes that respire CF to DCM and others that biodegrade DCM. The objectives of this study were to ascertain if a commercially available bioaugmentation enrichment culture (KB-1 Plus CF) uses an oxidative or fermentative pathway for biodegradation of DCM and to determine if the products from DCM biodegradation can support organohalide respiration of CF to DCM in the absence of an exogenous electron donor. In various treatments with the KB-1 Plus CF culture to which 14C-CF was added, the predominant product was 14CO2, indicating that oxidation is the predominant pathway for DCM. Recovery of 14C-DCM when biodegradation was still in progress confirmed that CF first undergoes reductive dechlorination to DCM. 14C-labeled organic acids, including acetate and propionate, were also recovered, suggesting that synthesis of organic acids provides a sink for the electron equivalents from oxidation of DCM. When the biomass was washed to remove organic acids from prior additions of exogenous electron donor and only CF and DCM were added, the culture completely dechlorinated CF. The total amount of DCM added was not sufficient to provide the electron equivalents needed to reduce CF to DCM. Thus, the additional reducing power came via the DCM generated from CF reduction. Nevertheless, the rate of CF consumption was considerably lower compared to that of treatments that received an exogenous electron donor. IMPORTANCE Chloroform (CF) and dichloromethane (DCM) are among the more commonly identified chlorinated aliphatic compounds found in contaminated soil and groundwater. One way to address this problem is to add microbes to the subsurface that can biodegrade these compounds. While microbes are known that can accomplish this task, less is known about the pathways used under anaerobic conditions. Some use an oxidative pathway, resulting mainly in carbon dioxide. Others use a fermentative pathway, resulting in formation of organic acids. In this study, a commercially available bioaugmentation enrichment culture (KB-1 Plus CF) was evaluated using carbon-14 labeled chloroform. The main product formed was carbon dioxide, indicating the use of an oxidative pathway. The reducing power gained from oxidation was shown to support reductive dechlorination of CF to DCM. The results demonstrate the potential to achieve full dechlorination of CF and DCM to nonhazardous products that are difficult to identify in the field.


Assuntos
Clorofórmio , Cloreto de Metileno , Anaerobiose , Biodegradação Ambiental , Radioisótopos de Carbono , Clorofórmio/metabolismo , Cloreto de Metileno/metabolismo , Peptococcaceae
10.
J Sep Sci ; 43(11): 2125-2132, 2020 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-32073721

RESUMO

Methanol-chloroform based protein precipitation is an essential step in many liquid chromatography-tandem mass spectrometry-based cellular proteomics applications. However, re-solubilization of the total protein precipitate is difficult using regular in-solution digestion protocol. Sodium deoxycholate is reported as an efficient surfactant for re-solubilization of membrane fractions. In this study, we demonstrated an application combining methanol-chloroform based protein precipitations and deoxycholic acid assisted re-solubilization of pellets to evaluate the improvement of protein identifications in mass spectrometry-based bottom-up proteomics. We evaluated the modified method using an equal amount of Raw 264.7 mouse macrophage cell lysate. Detailed in-solution trypsin digestion studies were presented on methanol-chloroform precipitated samples with or without deoxycholic acid treatments and compared with popular sample digestion methods. A mass spectrometric analysis confirmed an 82% increase in protein identification in deoxycholic acid-treated samples compared to other established methods. Furthermore, liquid chromatography-tandem mass spectrometry analysis of an equal amount of proteins from methanol-chloroform precipitated, and methanol-chloroform/deoxycholic acid-treated macrophage cell lysate showed a 14% increase and 27% unique protein identifications. We believe this improved digestion method could be a complementary or alternative method for mammalian cell sample preparations where sodium dodecyl sulfate based lysis buffer is frequently used.


Assuntos
Clorofórmio/metabolismo , Metanol/metabolismo , Proteômica , Tripsina/análise , Tripsina/metabolismo , Animais , Bicarbonatos/química , Bicarbonatos/metabolismo , Clorofórmio/química , Cromatografia Líquida , Metanol/química , Camundongos , Células RAW 264.7 , Soluções , Espectrometria de Massas em Tandem
11.
PLoS One ; 14(11): e0224932, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31710629

RESUMO

A new telemetric system for the electrochemical monitoring of dissolved oxygen is showed. The device, connected with two amperometric sensors, has been successfully applied to the wireless detection of the extracellular oxygen in the central complex of freely-walking Gromphadorhina portentosa. The unit was composed of a potentiostat, a two-channel sensor conditioning circuit, a microprocessor module, and a wireless serial transceiver. The amperometric signals were digitalized and sent to a notebook using a 2.4 GHz transceiver while a serial-to-USB converter was connected to a second transceiver for completing the communication bridge. The software, running on the laptop, allowed to save and graph the oxygen signals. The electronics showed excellent stability and the acquired data was linear in a range comprised between 0 and -165 nA, covering the entire range of oxygen concentrations. A series of experiments were performed to explore the dynamics of dissolved oxygen by exposing the animals to different gases (nitrogen, oxygen and carbon dioxide), to low temperature and anesthetic agents (chloroform and triethylamine). The resulting data are in agreement with previous O2 changes recorded in the brain of awake rats and mice. The proposed system, based on simple and inexpensive components, can constitute a new experimental model for the exploration of central complex neurochemistry and it can also work with oxidizing sensors and amperometric biosensors.


Assuntos
Técnicas Biossensoriais/instrumentação , Baratas/fisiologia , Oxigênio/análise , Tecnologia de Sensoriamento Remoto/instrumentação , Animais , Dióxido de Carbono/metabolismo , Clorofórmio/metabolismo , Baratas/metabolismo , Desenho de Equipamento , Etilaminas/metabolismo , Masculino , Nitrogênio/metabolismo , Software , Caminhada , Tecnologia sem Fio
12.
Biotechnol Bioeng ; 116(6): 1439-1448, 2019 06.
Artigo em Inglês | MEDLINE | ID: mdl-30712264

RESUMO

Chloroform (CF) can undergo reductive dechlorination to dichloromethane, chloromethane, and methane. However, competition for hydrogen (H2 ), the electron-donor substrate, may cause poor dechlorination when multiple electron acceptors are present. Common acceptors in anaerobic environments are nitrate (NO3- ), sulfate (SO42- ), and bicarbonate (HCO3- ). We evaluated CF dechlorination in the presence of HCO3- at 1.56 e- Eq/m2 -day, then NO3- at 0.04-0.15 e- Eq/m2 -day, and finally NO3- (0.04 e- Eq/m2 -day) along with SO42- at 0.33 e- Eq/m2 -day in an H2 -based membrane biofilm reactor (MBfR). When the biofilm was initiated with CF-dechlorination conditions (no NO3- or SO42- ), it yielded a CF flux of 0.14 e- Eq/m2 -day and acetate production via homoacetogenesis up to 0.26 e- eq/m2 -day. Subsequent addition of NO3- at 0.05 e- Eq/m2 -day maintained full CF dechlorination and homoacetogenesis, but NO3- input at 0.15 e- Eq/m2 -day caused CF to remain in the reactor's effluent and led to negligible acetate production. The addition of SO42- did not affect CF reduction, but SO42- reduction significantly altered the microbial community by introducing sulfate-reducing Desulfovibrio and more sulfur-oxidizing Arcobacter. Dechloromonas appeared to carry out CF dechlorination and denitrification, whereas Acetobacterium (homoacetogen) may have been involved with hydrolytic dechlorination. Modifications to the electron acceptors fed to the MBfR caused the microbial community to undergo changes in structure that reflected changes in the removal fluxes.


Assuntos
Biofilmes , Reatores Biológicos/microbiologia , Chloroflexi/fisiologia , Clorofórmio/metabolismo , Poluentes Químicos da Água/metabolismo , Bicarbonatos/metabolismo , Clorofórmio/isolamento & purificação , Elétrons , Membranas Artificiais , Nitratos/metabolismo , Sulfatos/metabolismo , Poluentes Químicos da Água/isolamento & purificação , Purificação da Água/métodos
13.
Sci Total Environ ; 656: 1063-1070, 2019 Mar 15.
Artigo em Inglês | MEDLINE | ID: mdl-30625638

RESUMO

Microcystis aeruginosa (M. aeruginosa) commonly blooms in summer while Cyclotella meneghiniana (C. meneghiniana) outbreaks in fall in water reservoirs of Southeast China. Pre-oxidation has been demonstrated to enhance the algae removal from chemical coagulation processes. However, excessive dosage of pre-oxidant can increase the disinfection by-products formation potential (DBPsFP). Additionally, the DBPs formation mechanisms from algae during the pre-oxidation-coagulation-chlorination processes have not well elucidated. In this study, the objectives were to investigate the trichloromethane (TCM) formation, the changes of water quality indexes, and the morphology changes of algal cells from M. aeruginosa or C. meneghiniana contaminated water during potassium permanganate (KMnO4) or chlorine (Cl2) pre-oxidation-coagulation-chlorination disinfection. The results showed that the TCM yield for two algal species decreased with the dosage increase of KMnO4 pre-oxidation, but increased with the dosage increase of pre-chlorination. Therefore, the 2.0 mg/L KMnO4 or 0.5 mg/L Cl2 was proposed as the optimal dosage for preventing both M. aeruginosa blooms in summer and for C. meneghiniana outbreaks in fall. M. aeruginosa exhibited a slightly higher TCM yield than C. meneghiniana in these treatment processes. Based on the release of potassium (K) ion and SEM analysis, KMnO4 had less damage on cell integrity than Cl2 at the dosage ≤2.0 mg/L. In addition, C. meneghiniana was easier to be disrupted by both pre-oxidants than M. aeruginosa, combining with subsequent coagulation led to different value of dissolved organic carbon (DOC), UV-visible absorbance (UV254) and turbidity.


Assuntos
Cloro/química , Clorofórmio/metabolismo , Diatomáceas/metabolismo , Microcystis/metabolismo , Permanganato de Potássio/química , Purificação da Água/métodos , Diatomáceas/citologia , Diatomáceas/efeitos dos fármacos , Relação Dose-Resposta a Droga , Floculação , Halogenação , Microcystis/citologia , Microcystis/efeitos dos fármacos , Oxidantes/química , Oxirredução , Qualidade da Água
14.
Spectrochim Acta A Mol Biomol Spectrosc ; 209: 186-195, 2019 Feb 15.
Artigo em Inglês | MEDLINE | ID: mdl-30388588

RESUMO

Camphor is known to be held in the substrate pocket of cytochrome P450cam enzyme via H-bond with a tyrosine residue of the enzyme in a unique orientation. This structural exclusivity results in regio- and stereo-specific hydroxylation of camphor by the enzyme. We have carried out a combined IR spectroscopic and quantum chemical investigation to shed light on the factors influencing the conformational exclusivity of 1R-(+)-camphor in the substrate pocket of Cytochrome P450cam, and to determine whether the selectivity is an inherent property of the substrate itself, or is imposed by the enzyme. For this purpose, complexes of camphor have been studied with three H-bond donors namely phenol, methanol and chloroform. Each of the three donors was found to form stable complexes with two distinct conformers; the one mimicking the conformation in enzyme substrate pocket was found to be more stable of the two, for all three donors. Experimentally, both conformers of the H-bonded complexes were identified separately for phenol and methanol in an argon matrix at 8 K, but not for chloroform due to very small energy barrier for interconversion of the two conformers. In room temperature solution phase spectra of camphor with all three donors, the differences in spectral attributes between the two isomeric H-bonded complexes were lost due to thermal motions.


Assuntos
Cânfora 5-Mono-Oxigenase/química , Cânfora/química , Clorofórmio/química , Metanol/química , Fenol/química , Teoria Quântica , Espectrofotometria Infravermelho/métodos , Sítios de Ligação , Cânfora/metabolismo , Cânfora 5-Mono-Oxigenase/metabolismo , Clorofórmio/metabolismo , Cristalografia por Raios X , Humanos , Ligação de Hidrogênio , Cinética , Metanol/metabolismo , Modelos Moleculares , Fenol/metabolismo , Ligação Proteica , Conformação Proteica , Especificidade por Substrato
15.
Mol Pharm ; 15(9): 3920-3930, 2018 09 04.
Artigo em Inglês | MEDLINE | ID: mdl-30067911

RESUMO

It has been proposed that general anesthesia results from direct multisite interactions with multiple and diverse ion channels in the brain. An understanding of the mechanisms by which general anesthetics modulate ion channels is essential to clarify their underlying behavior and their role in reversible immobilization and amnesia. Despite the fact that volatile general anesthetics are drugs that primarily induce insensitivity to pain, they have been reported to sensitize and active the vanilloid-1 receptor, TRPV1, which is known to mediate the response of the nervous system to certain harmful stimuli and which plays a crucial role in the pain pathway. Currently, the mechanism of action of anesthetics is unknown and the precise molecular sites of interaction have not been identified. Here, using ∼2.5 µs of classical molecular dynamics simulations and metadynamics, we explore these enigmas. Binding sites are identified and the strength of the association is further characterized using alchemical free-energy calculations. Anesthetic binding/unbinding proceeds primarily through a membrane-embedded pathway, and subsequently, a complex scenario is established involving multiple binding sites featuring single or multiple occupancy states of two small volatile drugs. One of the five anesthetic binding sites reported was previously identified experimentally, and another one, importantly, is identical to that of capsaicin, one of the chemical stimuli that activate TRPV1. However, in contrast to capsaicin, isoflurane and chloroform binding free-energies render modest to no association compared to capsaicin, suggesting a different activation mechanism. Uncovering chloroform and isoflurane modulatory sites will further our understanding of the TRPV1 molecular machinery and open the possibility of developing site-specific drugs.


Assuntos
Anestésicos Gerais/metabolismo , Canais de Cátion TRPV/química , Canais de Cátion TRPV/metabolismo , Animais , Sítios de Ligação , Capsaicina/metabolismo , Clorofórmio/metabolismo , Humanos , Isoflurano/metabolismo , Simulação de Dinâmica Molecular , Ligação Proteica , Domínios Proteicos
16.
Methods Enzymol ; 603: 115-128, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-29673521

RESUMO

Changes in electron spin content can be detected by X-band continuous-wave electron spin resonance (ESR, EPR) in Drosophila fruit flies without requiring the use of spin traps. The spin changes are related to cellular respiration and behave differently in anesthesia-resistant fly strains. We describe the method used in these measurements and its possible applications to the problem of the mechanism of general anesthesia.


Assuntos
Anestesia Geral/métodos , Anestésicos Gerais/química , Clorofórmio/química , Drosophila melanogaster/genética , Espectroscopia de Ressonância de Spin Eletrônica/métodos , Anestésicos Gerais/metabolismo , Animais , Clorofórmio/metabolismo , Drosophila melanogaster/metabolismo , Proteínas de Insetos/química , Proteínas de Insetos/metabolismo , Melaninas/química , Melaninas/metabolismo , Movimento , Mutação , Neurônios/citologia , Neurônios/metabolismo , Oxigênio/química , Oxigênio/metabolismo , Marcadores de Spin
17.
Chemosphere ; 198: 556-564, 2018 May.
Artigo em Inglês | MEDLINE | ID: mdl-29422245

RESUMO

S,S-ethylenediamine-N,N-disuccinic acid (EDDS) enhanced reductive dissolution of α-FeOOH by Shewanella putrefaciens CN32 (CN32), resulting in formation of surface-bound Fe(II) species (FeIIEDDS) to improve reductive dechlorination of carbon tetrachloride (CT). The pseudo-first-order rate constants for bio-reduction extents of α-FeOOH by CN32 in the presence of 1.36 mM EDDS was 0.023 ±â€¯0.0003 d-1 which was higher than without EDDS. The enhancement mechanism of bio-reduction was attributed to the strong complexation ability of EDDS to formed FeIIIEDDS, which could be better utilized by CN32. The dechlorination kinetic of CT by FeIIEDDS (2.016 h-1) in the presence of 1.36 mM EDDS was 24 times faster than without EDDS. Chloroform were detected as main products for the degradation of CT. The chemical analyses and morphological observation showed that combination between EDDS and Fe2+ produced FeIIEDDS complex, which had a reductive potential of -0.375 V and significantly enhanced CT dechlorination. The results showed that EDDS played an important role in enhancing the bio-reduction of α-FeOOH to accelerate reductive dechlorination of CT.


Assuntos
Tetracloreto de Carbono/metabolismo , Etilenodiaminas/metabolismo , Compostos de Ferro/metabolismo , Minerais/metabolismo , Shewanella putrefaciens/metabolismo , Succinatos/metabolismo , Quelantes/metabolismo , Clorofórmio/metabolismo , Halogenação/fisiologia , Ferro/química , Cinética , Oxirredução
18.
Phytochem Anal ; 29(2): 137-143, 2018 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-28881407

RESUMO

INTRODUCTION: 3-O-Acetyl-11-keto-ß-boswellic acid (AKBA), one of the pentacyclic triterpenoids, is the main biologically active constituent in the resin of Boswellia sacra and has received significant pharmacological interest in recent years. OBJECTIVE: It was aimed to develop a robust method to quantify the AKBA content in methanolic extracts of different parts of B. sacra plants and in various fractions of its resin exudates through near-infrared spectroscopy (NIRS) coupled with partial least squares regression (PLSR). MATERIAL AND METHODS: The near-infrared (NIR) spectra were used to measure the AKBA standards and B. sacra samples at a wavelength range between 700 and 2500 nm in absorption mode. A PLSR model was built from the obtained spectral data using 70% of the AKBA working standard solutions (training set), ranging from 0.1 ppm to 100 ppm. The final PLSR showed a R2 value of 99% with a root mean square error of cross-validation (RMSECV) value of 0.39% and a R2 value of 99%. RESULTS: The results showed that a 50% CHCl3 /n-hexane sub-fraction has the highest concentration of AKBA (14.8%), followed by 55% CHCl3 /n-hexane (13.6%), and 40% CHCl3 /n-hexane (6.1%). CONCLUSION: As the results achieved with the proposed NIRS methodology are in close agreement to the results of AKBA analysis using HPLC, we suggest that our proposed NIRS method is a fast alternative and non-destructive method for the analysis of AKBA in different samples of B. sacra. Copyright © 2017 John Wiley & Sons, Ltd.


Assuntos
Boswellia/química , Espectroscopia de Luz Próxima ao Infravermelho/métodos , Triterpenos/análise , Clorofórmio/metabolismo , Cromatografia Líquida de Alta Pressão , Hexanos/química , Análise dos Mínimos Quadrados , Modelos Químicos , Estruturas Vegetais/química , Solventes/química , Triterpenos/farmacologia
19.
J Contam Hydrol ; 203: 93-103, 2017 08.
Artigo em Inglês | MEDLINE | ID: mdl-28716488

RESUMO

The simultaneous anaerobic transformation of tetrachloroethene (PCE) and carbon tetrachloride (CT) was evaluated in a continuous flow column. The column was packed with quartz sand and bioaugmented with the Evanite culture (EV) that is capable of transforming PCE to ethene. Azizian and Semprini (2016) reported that PCE and CT could be simultaneously transformed in the column, with PCE (0.1mM) transformed mainly to ethene and CT (0.015mM) to chloroform (CF) (20%) and an unknown transformation product, likely carbon dioxide (CO2). The fermentation of propionate, formed from lactate fermentation, was inhibited after the transformation of CT, likely from the exposure to CF. Reported here is the second phase of that study where a second bioaugmentation of the EV culture was made to reintroduce a lactate and propionate fermenting population to the column. Effective lactate and propionate fermentation were restored with a H2 concentration of ~25nM maintained in the column effluent. PCE (0.1mM) was effectively transformed to ethene (~98%) and vinyl chloride (VC) (~2%). Unlabeled CT (0.015 to 0.03mM) was completely transformed with a transient build-up of CF and chloromethane (CM), which were subsequently removed below their detection limits. A series of transient tests were initiated through the addition of carbon-13 labeled CT (13CT), with concentrations gradually increased from 0.03 to 0.10mM. GC-MS analysis of the column effluent showed that 13C labeled CO2 (13CO2) was formed, ranging from 82 to 93% of the 13CT transformed, with the transient increases in 13CO2 associated with the increased concentration of 13CT. A modified COD analysis indicated a lesser amount of 13CT (18%) was transformed to soluble products, while 13CO2 represented 82% the 13CT transformed. In a final transient test, the influent lactate concentration was decreased from 1.1 to 0.67mM. The transformation of both CT and PCE changed dramatically. Only 59% of the 13CT was transformed, primarily to CF. 13CO2 concentrations gradually decreased to background levels, indicating CO2 was no longer a transformation product. PCE transformation resulted in the following percentage of products formed: cDCE (60%), VC (36%), and ethene (4%). Incomplete propionate fermentation was also observed, consistent with the build-up of CF and the decrease in H2 concentrations to approximately 2nM. The results clearly demonstrate that high concentrations of CT were transformed to CO2, and effective PCE dehalogenation to ethene was maintained when excess lactate was fed and propionate was effectively fermented. However, when the lactate concentration was reduced, both PCE and CT transformation and propionate fermentation were negatively impacted.


Assuntos
Dióxido de Carbono/metabolismo , Tetracloreto de Carbono/metabolismo , Etilenos/metabolismo , Tetracloroetileno/metabolismo , Anaerobiose , Biodegradação Ambiental , Reatores Biológicos/microbiologia , Dióxido de Carbono/química , Isótopos de Carbono/análise , Tetracloreto de Carbono/química , Clorofórmio/química , Clorofórmio/metabolismo , Etilenos/química , Halogenação , Tetracloroetileno/química , Cloreto de Vinil/química , Cloreto de Vinil/metabolismo , Poluentes Químicos da Água/química , Poluentes Químicos da Água/metabolismo
20.
Chem Asian J ; 12(16): 1997-2007, 2017 Aug 17.
Artigo em Inglês | MEDLINE | ID: mdl-28569439

RESUMO

It is well established that the majority of chlorinated organic substances found in the terrestrial environment are produced naturally. The presence of these compounds in soils is not limited to a single ecosystem. Natural chlorination is also a widespread phenomenon in grasslands and agricultural soils typical for unforested areas. These chlorinated compounds are formed from chlorination of natural organic matter consisting of very complex chemical structures, such as lignin. Chlorination of several lignin model compounds results in the intermediate formation of trichloroacetyl-containing compounds, which are also found in soils. These decay, in general, through a haloform-type reaction mechanism to CHCl3 . Upon release into the atmosphere, CHCl3 will produce chlorine radicals through photolysis, which will, in turn, lead to natural depletion of ozone. There is evidence that fungal chloroperoxidases able to produce HOCl are involved in the chlorination of natural organic matter. The objective of this review is to clarify the role and source of the various chloroperoxidases involved in the natural formation of CHCl3 .


Assuntos
Cloreto Peroxidase/metabolismo , Compostos Clorados/síntese química , Clorofórmio/síntese química , Meio Ambiente , Cloreto Peroxidase/química , Compostos Clorados/química , Compostos Clorados/metabolismo , Clorofórmio/química , Clorofórmio/metabolismo , Fungos/química , Fungos/enzimologia , Fotólise , Solo/química
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