Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 11.081
Filtrar
2.
Water Sci Technol ; 81(6): 1191-1208, 2020 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-32597406

RESUMO

The increasing use of dyestuff in industrial applications brings with it environmental problems. These dyes, which are an eco-toxic hazard, are common water pollutants, even at very low concentrations in water resources. Therefore, they must be removed in an economical way. In this study, low-cost biosorbents such as pine cone char, walnut shell char, and hazelnut shell char were prepared by pyrolysis process at different carbonization temperatures in the range of 400-700 °C. Biochars with the highest surface area were used to remove alizarin yellow GG from aqueous solution and the adsorption capacities of these materials were compared to commercially available activated carbon. Biomasses and prepared biochars were characterized using Fourier transform infrared spectroscopy, thermogravimetric/differential thermogravimetry analysis, Brunauer-Emmett-Teller (BET), scanning electron microscopy/energy dispersive X-ray spectroscopy, partial and elemental analysis techniques. Operational parameters such as contact time, temperature, pH, adsorbent dosage, and initial dye concentration were considered as variables for the batch adsorption experiments. Among the biochars used, the highest adsorption efficiency (82%) was obtained in pine cone char (BET surface area 259.74 m2/g) at pH = 3, T = 45 °C, adsorbent dosage of 8 g/L, and initial dye concentration of 20 ppm. The adsorption mechanism has been investigated by applying different kinetic and isotherm models with the aid of time-dependent adsorption data. The adsorption process was best described by Langmuir isotherm and pseudo-second order kinetic model.


Assuntos
Carvão Vegetal , Poluentes Químicos da Água , Adsorção , Compostos Azo , Concentração de Íons de Hidrogênio , Cinética , Pirólise , Salicilatos , Espectroscopia de Infravermelho com Transformada de Fourier
4.
Pestic Biochem Physiol ; 166: 104562, 2020 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-32448417

RESUMO

The buff-tailed bumblebee, Bombus terrestris audax is an important pollinator within both landscape ecosystems and agricultural crops. During their lifetime bumblebees are regularly challenged by various environmental stressors including insecticides. Historically the honey bee (Apis mellifera spp.) has been used as an 'indicator' species for 'standard' ecotoxicological testing, but it has been suggested that it is not always a good proxy for other eusocial or solitary bees. To investigate this, the susceptibility of B. terrestris to selected pesticides within the neonicotinoid, pyrethroid and organophosphate classes was examined using acute insecticide bioassays. Acute oral and topical LD50 values for B. terrestris against these insecticides were broadly consistent with published results for A. mellifera. For the neonicotinoids, imidacloprid was highly toxic, but thiacloprid and acetamiprid were practically non-toxic. For pyrethroids, deltamethrin was highly toxic, but tau-fluvalinate only slightly toxic. For the organophosphates, chlorpyrifos was highly toxic, but coumaphos practically non-toxic. Bioassays using insecticides with common synergists enhanced the sensitivity of B. terrestris to several insecticides, suggesting detoxification enzymes may provide a level of protection against these compounds. The sensitivity of B. terrestris to compounds within three different insecticide classes is similar to that reported for honey bees, with marked variation in sensitivity to different insecticides within the same insecticide class observed in both species. This finding highlights the need to consider each compound within an insecticide class in isolation rather than extrapolating between different insecticides in the same class or sharing the same mode of action.


Assuntos
Inseticidas , Animais , Abelhas , Combinação de Medicamentos , Ecossistema , Glicerol , Salicilatos
5.
Sci Rep ; 10(1): 4746, 2020 03 16.
Artigo em Inglês | MEDLINE | ID: mdl-32179788

RESUMO

Ginkgolic acids (GA) are alkylphenol constituents of the leaves and fruits of Ginkgo biloba. GA has shown pleiotropic effects in vitro, including: antitumor effects through inhibition of lipogenesis; decreased expression of invasion associated proteins through AMPK activation; and potential rescue of amyloid-ß (Aß) induced synaptic impairment. GA was also reported to have activity against Escherichia coli and Staphylococcus aureus. Several mechanisms for this activity have been suggested including: SUMOylation inhibition; blocking formation of the E1-SUMO intermediate; inhibition of fatty acid synthase; non-specific SIRT inhibition; and activation of protein phosphatase type-2C. Here we report that GA inhibits Herpes simplex virus type 1 (HSV-1) by inhibition of both fusion and viral protein synthesis. Additionally, we report that GA inhibits human cytomegalovirus (HCMV) genome replication and Zika virus (ZIKV) infection of normal human astrocytes (NHA). We show a broad spectrum of fusion inhibition by GA of all three classes of fusion proteins including HIV, Ebola virus (EBOV), influenza A virus (IAV) and Epstein Barr virus (EBV). In addition, we show inhibition of a non-enveloped adenovirus. Our experiments suggest that GA inhibits virion entry by blocking the initial fusion event. Data showing inhibition of HSV-1 and CMV replication, when GA is administered post-infection, suggest a possible secondary mechanism targeting protein and DNA synthesis. Thus, in light of the strong effect of GA on viral infection, even after the infection begins, it may potentially be used to treat acute infections (e.g. Coronavirus, EBOV, ZIKV, IAV and measles), and also topically for the successful treatment of active lesions (e.g. HSV-1, HSV-2 and varicella-zoster virus (VZV)).


Assuntos
Antivirais/farmacologia , Infecções por Vírus de DNA/metabolismo , Vírus de DNA/efeitos dos fármacos , Infecções por Vírus de RNA/metabolismo , Vírus de RNA/efeitos dos fármacos , Salicilatos/farmacologia , Proteínas do Envelope Viral/antagonistas & inibidores , Proteínas Virais de Fusão/antagonistas & inibidores , Animais , Astrócitos/metabolismo , Chlorocebus aethiops , Replicação do DNA/efeitos dos fármacos , Infecções por Vírus de DNA/virologia , Vírus de DNA/genética , DNA Viral/genética , Células HEK293 , Humanos , Infecções por Vírus de RNA/virologia , Vírus de RNA/genética , Células Vero , Proteínas do Envelope Viral/biossíntese , Proteínas Virais de Fusão/biossíntese , Vírion/efeitos dos fármacos , Internalização do Vírus/efeitos dos fármacos , Replicação Viral/efeitos dos fármacos
6.
Clin Nurse Spec ; 34(2): 45-47, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32068631

RESUMO

Recently, there seems to be more creative advertising regarding bismuth subsalicylate (BSS) for lots of gastrointestinal issues. I have found during medication reconciliation that some patients overuse and believe use of BSS products is without risks. From an advertising perspective, there seem to be many happy persons consuming BSS with no mention of restrictions or safety recommendations. What are the risks associated with its use? How effective is BSS? What about drug interactions?


Assuntos
Bismuto/uso terapêutico , Compostos Organometálicos/uso terapêutico , Salicilatos/uso terapêutico , Bismuto/efeitos adversos , Medicina de Família e Comunidade , Humanos , Enfermeiras Clínicas , Compostos Organometálicos/efeitos adversos , Salicilatos/efeitos adversos
7.
J Chromatogr A ; 1618: 460876, 2020 May 10.
Artigo em Inglês | MEDLINE | ID: mdl-31980262

RESUMO

For this work, a novel air-assisted liquid-liquid microextraction based on solidification of floating deep eutectic solvent (AA-LLME-SFDES), coupled with a high performance liquid chromatography (HPLC) method was developed for the detection of benzophenone and salicylate ultraviolet filters in water samples. Three types of fatty acid-based hydrophobic deep eutectic solvents (DESs) with low viscosity, low-density, and melting point close to room temperature were prepared and employed as extraction solvents. This air-assisted liquid-liquid microextraction was carried out in a glass centrifuge tube. Subsequently, the glass tube was introduced into ice-water bath and held for 3 min, during which the upper DES phase was solidified. The water phase was easily extracted using a syringe equipped with a long needle, and later, the glass tube was removed from ice-water bath. The solidified DES phase was immediately melted at room temperature and used for HPLC analysis. The response surface methodology was employed to optimize some influencing parameters such as the volume of the extraction solvent, the pH value of sample solution, the number of extraction cycles, and the addition of salt. A quadratic model, namely a central composite design, was used to replace the conventional single factor analysis. It was found that under optimal conditions, the limits of determination and quantification were 0.045-0.54 µg L-1 and 0.15-2.0 µg L-1, respectively. The relative standard deviations for inter-day (n = 5) and intra-day (n = 5) precision were ≤ 4.2%, whereas the enrichment factors for the ultraviolet filters were obtained from 41 to 50. Furthermore, this novel method was successfully employed for the detection of benzophenone and salicylate ultraviolet filters from real water samples. The recoveries ranged from 87.5% to 105.8%, whereas the RSDs were lower than 3.6%.


Assuntos
Benzofenonas/análise , Técnicas de Química Analítica/métodos , Cromatografia Líquida de Alta Pressão , Microextração em Fase Líquida , Salicilatos/análise , Solventes/química , Ácidos Graxos/análise , Interações Hidrofóbicas e Hidrofílicas , Limite de Detecção , Raios Ultravioleta , Água/química , Poluentes Químicos da Água/análise
8.
JAMA ; 323(3): 256-267, 2020 01 21.
Artigo em Inglês | MEDLINE | ID: mdl-31961417

RESUMO

Importance: A prior pilot study demonstrated the systemic absorption of 4 sunscreen active ingredients; additional studies are needed to determine the systemic absorption of additional active ingredients and how quickly systemic exposure exceeds 0.5 ng/mL as recommended by the US Food and Drug Administration (FDA). Objective: To assess the systemic absorption and pharmacokinetics of the 6 active ingredients (avobenzone, oxybenzone, octocrylene, homosalate, octisalate, and octinoxate) in 4 sunscreen products under single- and maximal-use conditions. Design, Setting, and Participants: Randomized clinical trial at a clinical pharmacology unit (West Bend, Wisconsin) was conducted in 48 healthy participants. The study was conducted between January and February 2019. Interventions: Participants were randomized to 1 of 4 sunscreen products, formulated as lotion (n = 12), aerosol spray (n = 12), nonaerosol spray (n = 12), and pump spray (n = 12). Sunscreen product was applied at 2 mg/cm2 to 75% of body surface area at 0 hours on day 1 and 4 times on day 2 through day 4 at 2-hour intervals, and 34 blood samples were collected over 21 days from each participant. Main Outcomes and Measures: The primary outcome was the maximum plasma concentration of avobenzone over days 1 through 21. Secondary outcomes were the maximum plasma concentrations of oxybenzone, octocrylene, homosalate, octisalate, and octinoxate over days 1 through 21. Results: Among 48 randomized participants (mean [SD] age, 38.7 [13.2] years; 24 women [50%]; 23 white [48%], 23 African American [48%], 1 Asian [2%], and 1 of unknown race/ethnicity [2%]), 44 (92%) completed the trial. Geometric mean maximum plasma concentrations of all 6 active ingredients were greater than 0.5 ng/mL, and this threshold was surpassed on day 1 after a single application for all active ingredients. For avobenzone, the overall maximum plasma concentrations were 7.1 ng/mL (coefficient of variation [CV], 73.9%) for lotion, 3.5 ng/mL (CV, 70.9%) for aerosol spray, 3.5 ng/mL (CV, 73.0%) for nonaerosol spray, and 3.3 ng/mL (CV, 47.8%) for pump spray. For oxybenzone, the concentrations were 258.1 ng/mL (CV, 53.0%) for lotion and 180.1 ng/mL (CV, 57.3%) for aerosol spray. For octocrylene, the concentrations were 7.8 ng/mL (CV, 87.1%) for lotion, 6.6 ng/mL (CV, 78.1%) for aerosol spray, and 6.6 ng/mL (CV, 103.9%) for nonaerosol spray. For homosalate, concentrations were 23.1 ng/mL (CV, 68.0%) for aerosol spray, 17.9 ng/mL (CV, 61.7%) for nonaerosol spray, and 13.9 ng/mL (CV, 70.2%) for pump spray. For octisalate, concentrations were 5.1 ng/mL (CV, 81.6%) for aerosol spray, 5.8 ng/mL (CV, 77.4%) for nonaerosol spray, and 4.6 ng/mL (CV, 97.6%) for pump spray. For octinoxate, concentrations were 7.9 ng/mL (CV, 86.5%) for nonaerosol spray and 5.2 ng/mL (CV, 68.2%) for pump spray. The most common adverse event was rash, which developed in 14 participants. Conclusions and Relevance: In this study conducted in a clinical pharmacology unit and examining sunscreen application among healthy participants, all 6 of the tested active ingredients administered in 4 different sunscreen formulations were systemically absorbed and had plasma concentrations that surpassed the FDA threshold for potentially waiving some of the additional safety studies for sunscreens. These findings do not indicate that individuals should refrain from the use of sunscreen. Trial Registration: ClinicalTrials.gov Identifier: NCT03582215.


Assuntos
Propiofenonas/sangue , Absorção Cutânea , Protetores Solares/farmacocinética , Acrilatos/sangue , Acrilatos/farmacocinética , Adulto , Benzofenonas/sangue , Benzofenonas/farmacocinética , Cinamatos/sangue , Cinamatos/farmacocinética , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Propiofenonas/farmacocinética , Salicilatos/sangue , Salicilatos/farmacocinética , Protetores Solares/efeitos adversos
9.
Pest Manag Sci ; 76(2): 589-596, 2020 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-31297926

RESUMO

BACKGROUND: Thrips Anaphothrips obscurus are one of the cosmopolitan major pests feeding on cereals and other grasses. In order to develop alternatives of chemical insecticides for thrips control, based on fumigant activity screening and evaluation of 22 essential oil (EO) compounds against the thrips, the binary interactions of methyl salicylate and carvacrol (MS-C) with high fumigant toxicity were studied systematically by bioassay and field trials. RESULTS: The bioassay results showed that six in 22 EO compounds had high fumigant toxicity against both the second-instar nymphs and adults of A. obscurus, including methyl salicylate, carvacrol, thymol, trans-cinnamaldehyde, diallyl trisulfide, and L-perillaldehyde. Furthermore, the combination of methyl salicylate mixed with carvacrol at a volume ratio of 5:5 exhibited the most significant synergism against A. obscurus, with a poison ratio value of 1.32 and a co-toxicity coefficient of 151.15. The optimal formulation of microemulsion (ME) was composed of 5% methyl salicylate, 5% carvacrol, 46% adjuvant and 44% deionized water. The result of dynamic light scattering and stability showed that MS-C 10% ME was a transparent, single-phase and homogeneous liquid system. Field trials indicated that the ME displayed a significant control efficacy of about 89.17% on thrips in peppers, and 82.59% in broad bean on the seventh day post application with a dosage of 600.0 g A.I hm-2 , respectively. CONCLUSION: The binary combination of MS-C possesses strikingly synergistic action against thrips A. obscurus, and the MS-C 10% ME has the potential to be developed as a botanical pesticide product for thrips control. © 2019 Society of Chemical Industry.


Assuntos
Tisanópteros , Animais , Cimenos , Inseticidas , Óleos Voláteis , Salicilatos
10.
J Chromatogr A ; 1613: 460673, 2020 Feb 22.
Artigo em Inglês | MEDLINE | ID: mdl-31708220

RESUMO

The uptake, translocation and transformation of three UV-blockers commonly employed in sunscreens, namely avobenzone, octocrylene and octisalate from water by Lemna gibba and Cyperus alternifolius was investigated. Reversed phase high performance liquid chromatography coupled to drift-tube ion-mobility quadrupole time-of-flight mass spectrometry was used for analyzing the extracts from the selected plants after incubation with the UV-blockers for one week. For avobenzone several transformation products resulting from hydroxylation, demethylation and oxidation of the parent molecule could be identified by measuring accurate mass, performing MS/MS experiments and by determining their drift-tube collision cross sections employing nitrogen as drift gas. In addition, the plants were subjected to two commercially available sunscreens, providing similar results to those obtained for the standard solutions of the UV-blockers. Finally, a kinetic study on the uptake and transformation of avobenzone, octocrylene and octisalate was conducted over a period of 216 h, revealing that the UV-filters were mostly present in their parent form and only to a smaller part converted into transformation products.


Assuntos
Araceae/metabolismo , Cromatografia Líquida de Alta Pressão , Cyperus/metabolismo , Protetores Solares/farmacocinética , Espectrometria de Massas em Tandem , Acrilatos/farmacocinética , Biotransformação , Espectrometria de Mobilidade Iônica , Propiofenonas/farmacocinética , Salicilatos/farmacocinética
11.
Chem Biodivers ; 17(1): e1900465, 2020 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-31701649

RESUMO

We performed comparative profiling of four specialized metabolites in the lichen Evernia prunastri, collected at three different geographic locations, California and Maine, USA, and Yoshkar Ola, Mari El, Russia. Among the compounds produced at high concentrations that were identified in all three specimens, evernic acid, usnic acid, lecanoric acid and chloroatranorin, evernic acid was the most abundant. Two depsidones, salazinic acid and physodic acid, were detected in the Yoshkar-Ola collection only. The crystalline structure of evernic acid (2-hydroxy-4-[(2-hydroxy-4-methoxy-6-methylbenzoyl)oxy]-6-methylbenzoate) (hmb) revealed two crystallographically and conformationally distinct hmb anions, along with two monovalent sodium atoms. One hmb moiety contained an exotetradentate binding mode to sodium, whereas the other exhibited an exohexadentate binding mode to sodium. Embedded edge-sharing {Na2 O8 }n sodium-oxygen chains connected the hmb anions into the full three-dimensional crystal structure of the title compound. The crystal used for single-crystal X-ray diffraction exhibited non-merohedral twinning. The data suggest the importance of the acetyl-polymalonyl pathway products to processes of maintaining integrity of the lichen holobiont community.


Assuntos
Benzofuranos/análise , Hidroxibenzoatos/análise , Líquens/química , Salicilatos/análise , Benzofuranos/metabolismo , Hidroxibenzoatos/metabolismo , Líquens/metabolismo , Modelos Moleculares , Salicilatos/metabolismo
12.
Clin Toxicol (Phila) ; 58(1): 16-19, 2020 01.
Artigo em Inglês | MEDLINE | ID: mdl-30900477

RESUMO

Introduction: Salicylate toxicity is a common cause of morbidity and hospitalization. Animal and human studies suggest that salicylates cause a dose-dependent inhibition of the activation of factors 2, 7, 9, and 10. However, limited reports of coagulopathy or major bleeding from salicylate toxicity exist.Methods: This is a retrospective study examining subjects from January 1, 2001 to December 31, 2011 in whom at least one serum salicylate concentration was measured above 30 mg/dL. Cases were patients with elevated salicylate concentration and coagulopathy (INR > 1.5). Major bleeding cases were those with elevated salicylate concentration who developed hemorrhagic death; or bleeding from an intracranial, intraspinal, intraocular, retroperitoneal, pericardial, intramuscular site; or hemoglobin decrease of >2 g/dL, or transfusion of at least 2 units of packed RBCs during hospitalization.Results: Twelve percent of all cases of elevated salicylate concentration developed coagulopathy, 6% developed major bleeding, and 3% died. In a multivariate model, duration of elevated salicylate concentration and renal impairment were associated with coagulopathy and no variable was associated with major bleeding. Patients were more likely to develop major bleeding if they had coagulopathy, but not all cases of major bleeding had coagulopathy.Discussion: Coagulopathy and major bleeding during salicylate toxicity has been underrecognized. Renal impairment and duration of salicylate elevation contribute to the risk of coagulopathy, but no factors predict major bleeding. Patients with coagulopathy have a high risk of bleeding but some bleeding occurs without coagulopathy, suggesting that other factors, such as platelet dysfunction, may play a role.Conclusion: Coagulopathy and major bleeding develop in a clinically relevant percentage of cases of salicylate toxicity.


Assuntos
Transtornos da Coagulação Sanguínea/induzido quimicamente , Hemorragia/induzido quimicamente , Salicilatos/toxicidade , Adolescente , Adulto , Fatores Etários , Idoso , Idoso de 80 Anos ou mais , Criança , Pré-Escolar , Humanos , Coeficiente Internacional Normatizado , Masculino , Pessoa de Meia-Idade , Estudos Retrospectivos , Fatores de Risco , Salicilatos/sangue , Adulto Jovem
13.
Anal Chim Acta ; 1096: 53-60, 2020 Feb 01.
Artigo em Inglês | MEDLINE | ID: mdl-31883591

RESUMO

Multivariate curve resolution has been applied to both simulated and experimental data sets where high or even complete overlapping occurs between component profiles in one data mode. It is shown that rotational ambiguity exists in the bilinear decomposition of the augmented data matrices built with second-order data for pure analyte standards and test samples containing uncalibrated interferents. However, even in the presence of rotational ambiguity, initialization based on the so-called purest variables in one of the data modes may allow one to develop analytical protocols with reasonable statistical indicators for the prediction of the analyte of interest. In one of the explored experimental systems, the analyte ciprofloxacin was determined in the presence of the interferent salicylate, measuring time decay-luminescence matrix data. The average prediction error was 0.02 mg L-1 in the test set, corresponding to a relative error of ca. 8%. In the second system, capillary electrophoresis with UV detection was employed to determine ciprofloxacin in aqueous samples in the presence of other fluoroquinolones, achieving analyte recoveries in the range 101-113%. Although further theoretical work may still be needed, the present analysis of the feasible component profiles after bilinear decomposition provides some clues to interpret the phenomenon.


Assuntos
Antibacterianos/análise , Ciprofloxacino/análise , Eletroforese Capilar/métodos , Fluoroquinolonas/análise , Medições Luminescentes/métodos , Água/análise , Calibragem , Simulação por Computador , Análise dos Mínimos Quadrados , Modelos Químicos , Análise Multivariada , Salicilatos/análise
14.
Food Chem ; 306: 125634, 2020 Feb 15.
Artigo em Inglês | MEDLINE | ID: mdl-31614291

RESUMO

The effects of postharvest treatments with γ-aminobutyric acid (GABA), methyl jasmonate (MeJA) or methyl salicylate (MeSA) on antioxidant systems and sensory quality of blood oranges during cold storage were evaluated (150 days at 3 °C plus 2 days at 20 °C, shelf life). Fruit firmness, titratable acidity (TA), total antioxidant activity (TAA) and ascorbic acid (AA) decreased during cold storage, all these changes being delayed in treated fruit, with the greatest differences observed with the 50 µmol L-1 MeJA and 100 µmol L-1 MeSA treatments. Total phenolic content (TPC), total anthocyanin content (TAC) and the major individual anthocyanins, cyanidin 3-glucoside and cyanidin 3-(6″-malonylglucoside), were found at higher concentration in treated fruit than in control during the whole cold storage period. Overall, 100 µmol L-1 MeSA was the most effective for maintaining fruit quality and maintained higher anthocyanin concentration due to higher phenylalanine ammonia-lyase (PAL) and lower polyphenol oxidase (PPO) activities.


Assuntos
Acetatos/farmacologia , Citrus sinensis/metabolismo , Ciclopentanos/farmacologia , Conservação de Alimentos , Oxilipinas/farmacologia , Salicilatos/farmacologia , Ácido gama-Aminobutírico/farmacologia , Antocianinas/metabolismo , Catecol Oxidase/metabolismo , Citrus sinensis/química , Citrus sinensis/efeitos dos fármacos , Temperatura Baixa , Frutas/química , Frutas/metabolismo , Glucosídeos/metabolismo , Valor Nutritivo , Fenilalanina Amônia-Liase/metabolismo
15.
Molecules ; 25(1)2019 Dec 22.
Artigo em Inglês | MEDLINE | ID: mdl-31877863

RESUMO

Choline salicylate (CS) as a derivative of acetylsalicylic acid is commonly used in different drug forms. In medicine, it is applied topically to inflammation of the oral cavity mucosa and in laryngology. However, this substance in the form of an ionic liquid has not been investigated enough. There are no literature studies on stability tests constituting a stage of pre-formulation research. HPLC (Nucleosil C18, 4.6 × 150 mm, 5 µm; methanol-water-acetic acid 60:40:1, 230 nm or 270 nm) and UV (276 nm) methods for the determination of CS in 2% (g/mL) aqueous solutions were developed. Under stress conditions, CS susceptibility to hydrolytic degradation in aqueous medium, hydrochloric acid, sodium hydroxide, and hydrogen peroxide, and the effect of light on the stability of CS solutions were studied with HPLC analysis. The degradation degree of CS and the purity of the solutions were also tested. Choline salicylate has been qualified as practically stable in neutral and acid media, stable in an alkaline medium, very stable in an oxidizing environment, and photolabile in solution. The HPLC-MS/MS method was used to identify 2,3- and 2,5-dihydroxybenzoic acids as degradation products of CS under the tested conditions.


Assuntos
Colina/análogos & derivados , Gentisatos/análise , Hidroxibenzoatos/análise , Salicilatos/química , Colina/química , Cromatografia Líquida de Alta Pressão , Combinação de Medicamentos , Estabilidade de Medicamentos , Hidrólise , Estrutura Molecular , Fotólise , Espectrometria de Massas em Tandem
16.
World J Microbiol Biotechnol ; 35(12): 186, 2019 Nov 14.
Artigo em Inglês | MEDLINE | ID: mdl-31728655

RESUMO

The pollution of aquatic environments by drugs is a problem for which scarce research has been conducted in regards of their removal. Amycolatopsis sp. Poz 14 presents the ability to biotransformation naphthalene at high efficiency, therefore, in this work this bacterium was proposed as an assimilator of naproxen and carbamazepine. Growth curves at different concentrations of naproxen and carbamazepine showed that Amycolatopsis sp. Poz 14 is able to utilize these drugs at a concentration of 50 mg L-1 as a source of carbon and energy. At higher concentrations, the bacterial growth was inhibited. The transformation kinetics of naproxen showed the total elimination of the compound in 18 days, but carbamazepine was only eliminated in 19.9%. The supplementation with cometabolites such as yeast extract and naphthalene (structure similar to naproxen) at 50 mg L-1, showed that the yeast extract shortened the naproxen elimination to 6 days and reached a higher global consumption rate compared to the naphthalene cometabolite. The biotransformation of carbamazepine was not improved by the addition of cometabolites. The partial sequencing of the genome of Amycolatopsis sp. Poz 14 detected genes encoding putative enzymes for the degradation of cyclic aromatic compounds and the activities of aromatic monooxygenase, catechol 1,2-dioxygenase and gentisate 1,2-dioxygenase exhibited their involving in the naproxen biodegradation. The HPLC-MS analysis detected the 5-methoxysalicylic acid at the end of the biotransformation kinetics. This work demonstrates that Amycolatopsis sp. Poz 14 utilizes naproxen and transforms it to 5-methoxysalicylic acid which is the initial compound for the catechol and gentisic acid metabolic pathway.


Assuntos
Actinomycetales/enzimologia , Actinomycetales/metabolismo , Redes e Vias Metabólicas , Naproxeno/metabolismo , Actinomycetales/efeitos dos fármacos , Actinomycetales/crescimento & desenvolvimento , Biodegradação Ambiental , Biotransformação , Carbamazepina/metabolismo , Carbamazepina/farmacologia , Carbono/metabolismo , Catecol 1,2-Dioxigenase , Catecóis , Dioxigenases , Poluição Ambiental , Gentisatos , Éteres de Hidroxibenzoatos/metabolismo , Cinética , Oxigenases de Função Mista , Naftalenos/metabolismo , Naproxeno/farmacologia , Salicilatos/metabolismo
17.
Environ Sci Pollut Res Int ; 26(36): 36754-36763, 2019 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-31741276

RESUMO

Stereocaulon sorediiferum is expected to be a Cu-hyperaccumulator lichen and has fluorescent substances. To clarify the relationship between the fluorescence (FL) of the lichen and its Cu concentration, we collected S. sorediiferum samples at Cu-contaminated and uncontaminated sites in Japan, determined the concentration of Cu, K, Mg, Al, Ca, Mn, Fe, Zn, chlorophyll a,b, and total carotenoids in them, analyzed lichen secondary metabolites and fluorescent substances extracted from them, and measured the FL of them and their extracts. We found that the FL intensity of S. sorediiferum samples is significantly negatively correlated with their Cu concentration. The application of its FL for Cu monitoring may allow a new nondestructive quantitative method for assessing Cu contamination. The spectroscopic and chromatographic analysis shows that the fluorescent substances negatively correlated with Cu concentration are not major lichen secondary metabolites (lobaric acid and atranorin) and remain after immersion in acetone. The correlation analysis and the comparison with the causal relationship between Cu concentration and the chlorophyll a/b ratio suggest that the reason for the decrease in FL intensity with increasing Cu concentration is a structural change of the fluorescent substances by accumulated Cu. These findings lead to a better understanding of the relationship between the FL of S. sorediiferum and its Cu concentration and provide new insights into fluorescent lichen substances.


Assuntos
Poluentes Atmosféricos/toxicidade , Ascomicetos/efeitos dos fármacos , Cobre/toxicidade , Fluorescência , Poluentes Atmosféricos/metabolismo , Ascomicetos/metabolismo , Clorofila , Clorofila A , Cobre/análise , Cobre/metabolismo , Depsídeos , Hidroxibenzoatos , Japão , Lactonas , Líquens/química , Líquens/efeitos dos fármacos , Salicilatos
18.
Artigo em Inglês | MEDLINE | ID: mdl-31670058

RESUMO

Human studies investigating the efficacy of emergency decontamination protocols for chemical incidents require the use of non-hazardous chemical simulants. Methyl salicylate (MeS) has almost exclusively been used for this purpose. Whilst MeS is a simulant of the chemical warfare agent (CWA) sulphur mustard, it is not an ideal simulant for many other chemical threats with greater persistence and lower volatility. Benzyl salicylate (BeS) has been investigated here as a low toxicity simulant for lower volatility, persistent chemical threat agents and toxic industrial chemicals (TICs). To evaluate the suitability of BeS as a simulant for human decontamination studies a gas chromatography-triple quadrupole mass spectrometry method was designed, optimised and validated, for the analysis of human skin and hair. Quantification was achieved using isotope-dilution, EI and collision-induced dissociation and multiple reaction monitoring for both qualifier and quantifier ion transitions. The mass transitions were m/z 285 → 91 and m/z 210 → 181, respectively for the quantifier and qualifier ions of BeS, and m/z 289 → 91 and m/z 214 → 185 for the quantifier and qualifier ions for the BeS-d4 internal standard, respectively. The method exhibited excellent coefficients of determination (R2 = 0.9992-0.9999) with LOD and LOQ values at 0.023 ng/ml and 0.23 ng/ml. Across three Quality Controls (QCs), 11.5 ng/ml, 115 ng/ml and 1150 ng/ml) average accuracy (intra-day 95.6-100.3%, inter-day 98.5-104.91%) and precision (intra-day RSD (%) 2-13.7%, inter-day RSD (%) 3.3-8.8%) were determined. The validated method was applied in a proof of principle volunteer study for the determination of total BeS recovered from skin and hair. The average total BeS recovery after 70 min was 37.9% from skin and there was a significant increase between baseline and post-intervention levels for hair. These data demonstrate that BeS is an appropriate simulant for persistent chemicals and that the analytical method employed here is suitable for BeS analysis in human studies.


Assuntos
Substâncias para a Guerra Química/análise , Cromatografia Gasosa-Espectrometria de Massas/métodos , Salicilatos/análise , Espectrometria de Massas em Tandem/métodos , Adulto , Descontaminação/métodos , Feminino , Cabelo , Humanos , Marcação por Isótopo/métodos , Masculino , Pessoa de Meia-Idade , Reprodutibilidade dos Testes , Pele
19.
Appl Microbiol Biotechnol ; 103(23-24): 9619-9631, 2019 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-31686146

RESUMO

Type I polyketide synthases (PKSs) are large multi-domain proteins converting simple acyl-CoA thioesters such as acetyl-CoA and malonyl-CoA to a large diversity of biotechnologically interesting molecules. Such multi-step reaction cascades are of particular interest for applications in engineered microbial cell factories, as the introduction of a single protein with many enzymatic activities does not require balancing of several individual enzymatic activities. However, functional introduction of type I PKSs into heterologous hosts is very challenging as the large polypeptide chains often do not fold properly. In addition, PKS usually require post-translational activation by dedicated 4'-phosphopantetheinyl transferases (PPTases). Here, we introduce an engineered Corynebacterium glutamicum strain as a novel microbial cell factory for type I PKS-derived products. Suitability of C. glutamicum for polyketide synthesis could be demonstrated by the functional introduction of the 6-methylsalicylic acid synthase ChlB1 from Streptomyces antibioticus. Challenges related to protein folding could be overcome by translation fusion of ChlB1Sa to the C-terminus of the maltose-binding protein MalE from Escherichia coli. Surprisingly, ChlB1Sa was also active in the absence of a heterologous PPTase, which finally led to the discovery that the endogenous PPTase PptACg of C. glutamicum can also activate ChlB1Sa. The best strain, engineered to provide increased levels of acetyl-CoA and malonyl-CoA, accumulated up to 41 mg/L (0.27 mM) 6-methylsalicylic acid within 48 h of cultivation. Further experiments showed that PptACg of C. glutamicum can also activate nonribosomal peptide synthetases (NRPSs), rendering C. glutamicum a promising microbial cell factory for the production of several fine chemicals and medicinal drugs.


Assuntos
Corynebacterium glutamicum/genética , Corynebacterium glutamicum/metabolismo , Policetídeo Sintases/metabolismo , Policetídeos/metabolismo , Salicilatos/metabolismo , Escherichia coli/metabolismo , Microbiologia Industrial , Engenharia Metabólica/métodos , Streptomyces antibioticus/enzimologia
20.
Biomater Sci ; 7(12): 5482-5491, 2019 Nov 19.
Artigo em Inglês | MEDLINE | ID: mdl-31663590

RESUMO

Fenton reaction-based reactive oxygen species (ROS) generation provides a new idea for the design of ROS-mediated anticancer agents. Finding ways to increase iron uptake and to elevate the level of H2O2 in cells simultaneously is thus crucial to this strategy. Meanwhile, salicylic acid (SA) or its analogue, as the major metabolite of aspirin, has been reported to be closely associated with an intracellular redox-active product. In this work, a PEG-modified nanoscale coordination polymer (PFNC) via the self-assembly of 5-sulfosalicylic acid (SSA) with Fe3+ ions has been designed for the first time. The results show that the SSA dissociated from the PFNC can lead to the decrease of GSH and the accumulation of H2O2 in cancer cells, and thus elevate cellular ROS via the Fenton reaction. Owing to such intracellular oxidative stress, PFNC-induced ferroptotic cell death was further confirmed. In vitro cytotoxicity studies show that PFNCs display higher cytotoxicity on cancer cells than on normal cells. In vivo experiments further demonstrate that PFNCs not only possess high tumor accumulation, but also significantly inhibit the tumor growth without obvious damage toward the major organs. Based on the results, we expect that this work will provide an inspiration for understanding the role of SA, even aspirin, in the prevention of cancer.


Assuntos
Aspirina/química , Aspirina/farmacologia , Benzenossulfonatos/química , Quimioprevenção/métodos , Ferro/química , Polietilenoglicóis/química , Salicilatos/química , Antineoplásicos/química , Antineoplásicos/farmacologia , Humanos , Peróxido de Hidrogênio/química , Células MCF-7 , Estresse Oxidativo/efeitos dos fármacos , Espécies Reativas de Oxigênio/metabolismo
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA