RESUMEN
INTRODUCTION: Liver cirrhosis is a common ailment that is widely prevalent in our country and across the world. There are several manifestations of this disease. Metabolic bone disease also has an association with cirrhosis. The present study was designed to study the correlation between bone mineral density (BMD) and the severity of liver cirrhosis. MATERIALS AND METHODS: This was a case-control study. A total of 35 diagnosed cases of liver cirrhosis and 35 age and sex-matched controls were included in the study. BMD was measured by dual-energy X-ray absorptiometry (DEXA) at the hip joint and lumbar spine. Child-Turcotte-Pugh (CTP) score was used for assessing the severity of liver cirrhosis. RESULTS: Out of the 35 cases of cirrhosis, 25 had either osteopenia or osteoporosis. The mean T-score at the hip joint in cases was -1.47 ± 1.62 and in controls, it was -0.56 ± 1.67 (p < 0.001). The mean T-score detected in the lumbar spine was -1.33 ± 1.66 and in controls -0.41 ± 1.67 (p < 0.001). There was a significant inverse correlation between CTP scores and BMD. CONCLUSION: The present study revealed that abnormal BMD is highly prevalent in patients with liver cirrhosis. There is also a significant relationship between the severity of cirrhosis and BMD.
Asunto(s)
Enfermedades Óseas Metabólicas , Osteoporosis , Humanos , Densidad Ósea , Estudios de Casos y Controles , Osteoporosis/diagnóstico por imagen , Osteoporosis/epidemiología , Osteoporosis/etiología , Enfermedades Óseas Metabólicas/diagnóstico por imagen , Enfermedades Óseas Metabólicas/epidemiología , Enfermedades Óseas Metabólicas/etiología , Cirrosis Hepática/complicaciones , Vértebras Lumbares/diagnóstico por imagenRESUMEN
Intrinsically disordered proteins play important roles in cell signalling, transcription, translation and cell cycle regulation. Although they lack stable tertiary structure, many intrinsically disordered proteins undergo disorder-to-order transitions upon binding to partners. Similarly, several folded proteins use regulated order-to-disorder transitions to mediate biological function. In principle, the function of intrinsically disordered proteins may be controlled by post-translational modifications that lead to structural changes such as folding, although this has not been observed. Here we show that multisite phosphorylation induces folding of the intrinsically disordered 4E-BP2, the major neural isoform of the family of three mammalian proteins that bind eIF4E and suppress cap-dependent translation initiation. In its non-phosphorylated state, 4E-BP2 interacts tightly with eIF4E using both a canonical YXXXXLΦ motif (starting at Y54) that undergoes a disorder-to-helix transition upon binding and a dynamic secondary binding site. We demonstrate that phosphorylation at T37 and T46 induces folding of residues P18-R62 of 4E-BP2 into a four-stranded ß-domain that sequesters the helical YXXXXLΦ motif into a partly buried ß-strand, blocking its accessibility to eIF4E. The folded state of pT37pT46 4E-BP2 is weakly stable, decreasing affinity by 100-fold and leading to an order-to-disorder transition upon binding to eIF4E, whereas fully phosphorylated 4E-BP2 is more stable, decreasing affinity by a factor of approximately 4,000. These results highlight stabilization of a phosphorylation-induced fold as the essential mechanism for phospho-regulation of the 4E-BP:eIF4E interaction and exemplify a new mode of biological regulation mediated by intrinsically disordered proteins.
Asunto(s)
Factor 4E Eucariótico de Iniciación/química , Factor 4E Eucariótico de Iniciación/metabolismo , Factores Eucarióticos de Iniciación/química , Factores Eucarióticos de Iniciación/metabolismo , Proteínas Intrínsecamente Desordenadas/química , Proteínas Intrínsecamente Desordenadas/metabolismo , Pliegue de Proteína , Sitios de Unión , Humanos , Modelos Moleculares , Resonancia Magnética Nuclear Biomolecular , Fosforilación , Unión Proteica , Estructura Secundaria de Proteína , Transducción de SeñalRESUMEN
Impaired awareness of glycation biology in cancer initiation and progression is one of the fundamental reasons for its meticulous investigation of the molecules involved in signalling pathway. Glycation of biological macromolecules results in the progression of advanced glycation end-products (AGEs) that proliferates the process of carcinogenesis by activation of transcription factors and release of cytokines. The receptor for advanced glycation end-products (RAGEs) with the binding of its different ligands like; AGEs, HMGB1 and S100 activate the signalling arrays. The activation of downstream signalling pathway ultimately leads to the pathophysiological conditions of diabetes, ageing, neurological disorders and cancers as well as a result of the activation of transcription factors which is discussed in the main body text of this review. However, there might be a likelihood of the positive effect of the HMGB1 and S100 proteins in cancer. Still, some untouched mechanisms might be responsible for the establishment of the function of AGE-RAGE or AGE-sRAGE axis activation that leads to the friend-foe association with the cancers. The levels of RAGE and s-RAGE may be a useful biomarker of ligand-RAGE pathway activation and cancer. Thus, the possibility of providing a potential complement to carcinogenesis is very high which might be an interesting target for therapeutic interventions. This article is an insightful assessment on AGE, RAGE and s-RAGE for its possible role in cancer onset and progression. The novel therapeutic targets for cancer prevention or inhibition are also explained in brief in relation to AGE and RAGE.
Asunto(s)
Carcinogénesis/metabolismo , Productos Finales de Glicación Avanzada/metabolismo , Receptor para Productos Finales de Glicación Avanzada/sangre , Receptor para Productos Finales de Glicación Avanzada/metabolismo , Animales , Biomarcadores de Tumor/metabolismo , Daño del ADN , Glicosilación , Humanos , Inflamación/metabolismo , Ligandos , Estrés Oxidativo , Transducción de SeñalRESUMEN
The combine effect of oxidative and glycative stress predisposed to glycoxidation, and their outcomes that play critical role in lung cancer have been examined in different ways. The therapeutic approaches for lung cancer are still unsatisfactory. We observe some unclear and decisive pathways which might play an important role in targeting lung cancer. The roadmap of signaling pathway includes p38 MAPK, NF-ÆB, TNF-α and AGE-RAGE binding affinity play role in the cell growth, proliferation, apoptosis inhibition and metastasis. The goal of this review is to achieve a new signaling map inside the lung cancer which is mediated by glycoxidative products mainly reactive dicarbonyls and advanced glycation end products (AGEs). Additionally, AGE-RAGE binding critically regulates the suppression and promotion of lung cancer via inhibition and activation of different signaling pathways. Hence, this review suggests the role of oxidation, glycation, and glycoxidation in lung cancer.
Asunto(s)
Productos Finales de Glicación Avanzada/metabolismo , Neoplasias Pulmonares/metabolismo , Estrés Oxidativo , Receptor para Productos Finales de Glicación Avanzada/metabolismo , Apoptosis , Proliferación Celular , Glicosilación , Humanos , Neoplasias Pulmonares/patología , Neoplasias Pulmonares/fisiopatología , Oxidación-Reducción , Receptor para Productos Finales de Glicación Avanzada/fisiología , Transducción de SeñalRESUMEN
Glycation of biological macromolecules, due to hyperglycemia, promotes the formation of advanced glycation end products (AGEs). It is accelerated in diabetic patients and is responsible for the pathophysiology and progression of diabetes. Previous reports have shown that amount of AGEs formation and glycation-induced structural damage is higher in hemoglobin (Hb) than other proteins present in blood. In our previous study, we have shown structural changes in Hb by D-ribose which may result into the generation of immunogenic neo-epitopes. Thus, we hypothesized that D-ribose induced structural perturbations in Hb, could result in the formation of neo-epitopes which may provoke an auto-immune response and may also be involved in the immuno-pathogenesis of diabetes type-2 associated complications. Therefore, in the current study, we analyzed the prevalence of autoantibodies in diabetic patient's sera against D-ribose glycated-Hb by direct binding and competitive ELISA. Direct binding ELISA confirmed that autoantibodies in diabetic patients exhibit significantly high binding with D-ribose glycated-Hb as compared to its native form. The antigen binding specificity of these antibodies was also screened by competitive inhibition ELISA. We also used D-glucose glycated-Hb as a positive control to detect the presence of auto-antibodies by direct binding and inhibiton ELISA. We found that D-glucose glycated-Hb binds with T2DM samples but the affinity to binding is lower than D-ribose glycated-Hb. The overall findings of this study suggest the prevalence of circulating autoantibodies against D-ribose glycated-Hb in diabetic patients and thus, the level of these autoantibodies may be used as biomarker for progression of diabetes.
Asunto(s)
Autoanticuerpos/inmunología , Diabetes Mellitus/inmunología , Hemoglobina Glucada/química , Hemoglobina Glucada/inmunología , Ribosa/inmunología , Adulto , Reacciones Antígeno-Anticuerpo , Diabetes Mellitus/epidemiología , Ensayo de Inmunoadsorción Enzimática , Femenino , Glicosilación , Humanos , MasculinoRESUMEN
INTRODUCTION: Preeclampsia is one of the leading causes of maternal and neonatal morbidity and mortality. However there is growing evidence that there are differences during the post partum period between subjects with prior preeclampsia and prior uncomplicated pregnancy and women with a history of preeclampsia are more likely to develop cardiovascular disease later in life. The aim of our study was to assess the cardio- metabolic risk profile in women with previous history of pre-eclampsia and to their counterparts who had normal pregnancy. METHODS & MATERIAL: In a hospital based case-control study, 50 women aged 20-45 years who had history of preeclampsia and equal numbers of age matched women who had normal pregnancy were included. Apart from routine anthropometric and biochemical parameters, they were assessed for insulin resistance, Hs CRP (High sensitive C reactive protein) and flow mediated vasodilatation (FMD). RESULTS: Significant difference was noted with regard to BMI and waist circumference, systolic and diastolic blood pressures, and HOMA-IR which were higher and HDL and FMD were lower in women the previous preeclampsia than women with normal pregnancy. The prevalence of various cardio-metabolic risk factors increased in with increase in duration from index pregnancy. CONCLUSION: Women with previous history of preeclampsia had adverse cardio-metabolic profile than those who had normal pregnancy. They had higher insulin resistance and endothelial dysfunction. They also have high prevalence of chronic metabolic disorders with increased duration since index pregnancy.
Asunto(s)
Preeclampsia/epidemiología , Adulto , Presión Sanguínea , Índice de Masa Corporal , Estudios de Casos y Controles , HDL-Colesterol/sangre , Femenino , Humanos , Resistencia a la Insulina , Persona de Mediana Edad , Embarazo , Factores de Riesgo , Vasodilatación , Circunferencia de la Cintura , Adulto JovenRESUMEN
Wilson's disease is known for its protean manifestations due to abnormal copper metabolism. Although liver, brain and eyes are the well established sites for the latter but it can be speculated for other organs too. We report a case of Wilson's disease with tricuspid regurgitation possibly due to abnormal deposition of copper in heart.
Asunto(s)
Degeneración Hepatolenticular/diagnóstico , Adolescente , Humanos , Masculino , Terminología como AsuntoRESUMEN
A novel, unique, highly effective, and recyclable heterogeneous catalyst, diethyl imidazolium hexafluorophosphate ionic liquid supported metal-organic framework ([DEIm][PF6]@MOF-5), has been synthesized using a simple impregnation method at ambient temperature. Characterization of the catalyst was done through various techniques such as Fourier transform infrared (FTIR), energy dispersive X-ray, X-ray diffraction (XRD), transmission electron microscopy, scanning electron microscopy (SEM), elemental mapping, Raman spectroscopy, X-ray photoelectron spectroscopy, and thermogravimetric analysis (TGA) analyses. The kinetic study has shown the high catalytic performance of [DEIm][PF6]@MOF-5 for the reduction of 4-nitrophenol (NP) compared to other catalysts. The catalyst also exhibited efficient electrochemical activity toward 4-NP reduction. The catalyst was recyclable for more than seven cycles without any significant loss in its catalytic performance. The recycled catalyst was further studied using XRD, FTIR, SEM, and TGA analyses to investigate the structural changes that occurred during the reaction. The catalyst maintained its structural integrity even after seven cycles.
RESUMEN
BACKGROUND: Periodontitis is a chronic multifactorial inflammatory disease associated with dysbiotic plaque biofilms and characterized by progressive destruction of the tooth-supporting apparatus. Treatment of the periodontitis is a key challenge since the disease occurs due to microbial biofilm which is extremely resistant to host response and antimicrobials. Among non-surgical methods, scaling and root planning (SRP) is considered as the fundamental method and results in the utmost improvements. However, complete elimination of subgingival calculus is difficult. A substitute treatment in inhibition of subgingival microbiota can be attained by ozonated water at a concentration of 0.5-4 mg/L. Lately, laser light therapy has been proposed in periodontal therapy in an endeavor to improve the efficiency and effectiveness of bacterial elimination and root surface debridement. MATERIALS AND METHODS: 26 patients with chronic periodontitis were selected. The selected arches were randomly divided into two groups: Group-A was subjected to SRP + Ozone-Therapy and Group-B to SRP + Photodynamic-Therapy. Clinical parameters were recorded at baseline, 1&2months. Microbial parameters were recorded at baseline and 2-months. RESULTS: For both the groups significant decrease in clinical parameters were seen from baseline to 1 month and further in 2 months. On intergroup comparison of clinical parameters no significant result was found. Both the groups showed significant decrease in microbial parameters was seen from baseline to 2 months. On intergroup comparison of microbial parameters no significant result was found. CONCLUSION: Clinically and microbiologically, there was significant difference in both the groups between all time periods (P < 0.001), however there was no significant difference between the two groups at all periods (P > 0.05).
Asunto(s)
Periodontitis Crónica , Fotoquimioterapia , Humanos , Periodontitis Crónica/tratamiento farmacológico , Fotoquimioterapia/métodos , Agua , Fármacos Fotosensibilizantes/uso terapéutico , Aplanamiento de la Raíz/métodos , Resultado del Tratamiento , Enfermedad Crónica , Raspado DentalRESUMEN
Background: Treatment for metastatic neuroendocrine tumors (NETs) is often with somatostatin analogues (SSA) such as lanreotide in the first-line setting. Real world use of lanreotide in Canada is not well studied. Methods: We performed a retrospective chart review of 69 patients to study real world use of lanreotide at our centre. Results: Lanreotide was the first-line of systemic treatment in 60 patients. Watch-and-wait was a common strategy and was seen in 31 patients. SSA switch strategy was seldom applied. Majority of patients on lanreotide had low-grade NETs. Standard starting dose of lanreotide 120 mg every 28 days was used in 66 patients. Dose escalation to 120 mg every 21 days occurred in 7 patients. The primary intention for treatment was tumor control in 32 patients, and both tumor and symptom control in 34 patients. Median time on treatment was 21.6 months. Conclusions: Overall, our findings were in keeping with current guidelines. It will be interesting to assess how clinical practice evolves in the future and to determine the role of dose escalation for disease control.
RESUMEN
BACKGROUND: Medicinal plants have been found beneficial in the control and therapy of many ailments as they contain bioactive compounds, and many of them are used as precursors in the biosynthesis of natural medicines. Diuretics are used as a primary treatment in patients with edema associated with liver cirrhosis and kidney diseases, hyperkalemia, hypertension, heart failure, or renal failure. Furthermore, they are also used to increase the excretion of sodium and reduce blood volume. Due to various adverse events associated with synthetic diuretics, there is a need to investigate alternate plant-based bioactive components that have effective diuretic activity with minimal side effects. OBJECTIVE: This review compiled the reported bioactive compounds from different plant sources along with their mechanisms of diuretic activity. METHODS: Different sources were used to collect information regarding herbal plants with therapeutic value as diuretics. These included published peer-reviewed journal articles, scholarly articles from StatPearls, and search engines like Google Scholar, PubMed, Scopus, Springer, ScienceDirect, Wiley, etc. Results: In this review, it was found that flavonoids like rutin, acacetin, naringenin, etc. showed significant diuretic activity in experimental models by various mechanisms, but mostly by blocking the sodium-potassium-chloride co-transporter, while some bioactive compounds showed diuretic actions via other mechanisms as well. CONCLUSION: Research on clinical trials of these isolated bioactive compounds needs to be further conducted. Thus, this review provides an understanding of the potential diuretic bioactive compounds of plants for further research and pharmaceutical applications.
Asunto(s)
Hipertensión , Enfermedades Renales , Humanos , Diuréticos/efectos adversos , Diuresis , Hipertensión/diagnóstico , Hipertensión/tratamiento farmacológico , Hipertensión/inducido químicamente , Sodio/uso terapéuticoRESUMEN
A facile and ecofriendly synthesis of new chromonyl chalcones 3a-b from 3-formylchromone 1 and active methyl compounds 2a-b is reported under thermal solvent-free heating condition in good yields. The chromonyl chalcones 3a-b were used as intermediates under green condition for the synthesis of new bioactive pyrazoline derivatives 4a-f. The compounds were tested for antimicrobial activity by disk diffusion assay with slight modifications against Gram-positive, Gram-negative strains of bacteria as well as fungal strains. The investigation of antimicrobial screening revealed that compounds 3a-b and 4a-f showed antibacterial and antifungal activities.
Asunto(s)
Antibacterianos/farmacología , Antifúngicos/farmacología , Bacterias/efectos de los fármacos , Chalconas/farmacología , Hongos/efectos de los fármacos , Pirazoles/farmacología , Temperatura , Antibacterianos/síntesis química , Antibacterianos/química , Antifúngicos/síntesis química , Antifúngicos/química , Chalconas/síntesis química , Chalconas/química , Pruebas de Sensibilidad Microbiana , Estructura Molecular , Pirazoles/síntesis química , Pirazoles/químicaRESUMEN
A novel approach was adopted for the synthesis of series of new pyrazolyl chalcones (3a-c) by the reaction of 5-chloro-3-methyl-1-phenylpyrazole-4-carboxaldehyde (1) with different 5-acetylbarbituric acid derivatives (2a-c) under thermal solvent-free condition. The chalcones were then converted to the corresponding pyrazolines (4a-c) under the same condition in excellent yields. All the synthesized compounds were characterized using elemental analysis and spectral data (IR, (1)H NMR, and mass spectrometry). The synthesized compounds were tested for their antimicrobial activity by disk diffusion assay with slight modifications against Gram-positive, Gram-negative strains of bacteria as well as fungal strains. The investigation of antimicrobial screening revealed that compounds (3a-4c) showed good antibacterial and antifungal activities, respectively. Among the screened compounds, 3b showed more potent inhibitory activity (MIC=12.5 µg/ml) nearly to that of standard antibiotics ciprofloxacin, griseofulvin and fluconazole.
Asunto(s)
Antiinfecciosos , Bacterias/efectos de los fármacos , Chalconas/síntesis química , Chalconas/farmacología , Hongos/efectos de los fármacos , Pirazoles/síntesis química , Pirazoles/farmacología , Antiinfecciosos/síntesis química , Antiinfecciosos/química , Antiinfecciosos/farmacología , Chalconas/química , Espectroscopía de Resonancia Magnética , Pruebas de Sensibilidad Microbiana , Estructura Molecular , Pirazoles/química , Solventes/química , TemperaturaRESUMEN
A new series of 4-hydroxycoumarin derivatives 3a-d was synthesized by the reaction of 3-bromo-4-hydroxy coumarin 1 with various heteroaldehydes 2a-d in good yields. The synthesized compounds were characterized on the basis of their elemental and spectral (IR, (1)H-NMR and mass spectrometry) analysis. All target compounds were evaluated for their in-vitro antimicrobial activity against Streptococcus pyogenes, methicillin-resistant Staphylococcus aureus, Pseudomonas aeruginosa, Klebsiella pneumonia, and Escherichia coli bacterial strains and fungal cultures of Candida albicans, Aspergillus fumigatus, Trichophyton mentagrophytes, and Penicillium marneffei by disk diffusion assay with slight modifications. The minimum inhibitory concentration (MIC) was determined for the test compounds as well as for reference standards. Among the tested compounds, 3a has shown the most potent antibacterial as well as antifungal activities.
Asunto(s)
4-Hidroxicumarinas/farmacología , Antibacterianos/farmacología , Antifúngicos/farmacología , 4-Hidroxicumarinas/síntesis química , 4-Hidroxicumarinas/química , Antibacterianos/síntesis química , Antibacterianos/química , Antifúngicos/síntesis química , Antifúngicos/química , Bacterias/efectos de los fármacos , Hongos/efectos de los fármacos , Pruebas de Sensibilidad Microbiana , Análisis Espectral/métodos , Relación Estructura-ActividadRESUMEN
Background: Policy makers need access to reliable data to monitor and evaluate the progress of development outcomes and targets such as sustainable development outcomes (SDGs). However, significant data and evidence gaps remain. Lack of resources, limited capacity within governments and logistical difficulties in collecting data are some of the reasons for the data gaps. Big data-that is digitally generated, passively produced and automatically collected-offers a great potential for answering some of the data needs. Satellite and sensors, mobile phone call detail records, online transactions and search data, and social media are some of the examples of big data. Integrating big data with the traditional household surveys and administrative data can complement data availability, quality, granularity, accuracy and frequency, and help measure development outcomes temporally and spatially in a number of new ways.The study maps different sources of big data onto development outcomes (based on SDGs) to identify current evidence base, use and the gaps. The map provides a visual overview of existing and ongoing studies. This study also discusses the risks, biases and ethical challenges in using big data for measuring and evaluating development outcomes. The study is a valuable resource for evaluators, researchers, funders, policymakers and practitioners in their effort to contributing to evidence informed policy making and in achieving the SDGs. Objectives: Identify and appraise rigorous impact evaluations (IEs), systematic reviews and the studies that have innovatively used big data to measure any development outcomes with special reference to difficult contexts. Search Methods: A number of general and specialised data bases and reporsitories of organisations were searched using keywords related to big data by an information specialist. Selection Criteria: The studies were selected on basis of whether they used big data sources to measure or evaluate development outcomes. Data Collection and Analysis: Data collection was conducted using a data extraction tool and all extracted data was entered into excel and then analysed using Stata. The data analysis involved looking at trends and descriptive statistics only. Main Results: The search yielded over 17,000 records, which we then screened down to 437 studies which became the foundation of our systematic map. We found that overall, there is a sizable and rapidly growing number of measurement studies using big data but a much smaller number of IEs. We also see that the bulk of the big data sources are machine-generated (mostly satellites) represented in the light blue. We find that satellite data was used in over 70% of the measurement studies and in over 80% of the IEs. Authors' Conclusions: This map gives us a sense that there is a lot of work being done to develop appropriate measures using big data which could subsequently be used in IEs. Information on costs, ethics, transparency is lacking in the studies and more work is needed in this area to understand the efficacies related to the use of big data. There are a number of outcomes which are not being studied using big data, either due to the lack to applicability such as education or due to lack of awareness about the new methods and data sources. The map points to a number of gaps as well as opportunities where future researchers can conduct research.
RESUMEN
d-ribose, a reducing sugar, in diabetic hyperglycemia provokes non-enzymatic glycoxidation of hemoglobin (Hb), an abundant protein of red blood cells (RBCs). Different types of intermediates adduct formation occur during glycoxidation, such as advanced glycation end-products (AGEs) which lead to amyloid formation due to structural and conformational alterations in protein. Therefore, the study of these intermediate adducts plays a pivotal role to discern their relationship with diabetes mellitus and related disorders. Here, we investigated the interaction mechanism of d-ribose with Hb, and Hb prebound phytochemical thymoquinone (TQ). Our investigation reveals that the interaction of TQ with histidine residues of Hb interferes with the interaction of d-ribose with glycine residues at the glycation-site. Based on that, we had performed a time-based (21-days) in-vitro glycoxidation study at 37 °C to investigate the structural perturbation mechanism of Hb at different time-intervals in absence/presence of TQ. We found that prolonged glycoxidation induces amyloid formation in absence of TQ but in its presence, the process was prohibited. In summary, this study examined and characterized biophysically different intermediate-states of protein carrying glycoxidation-modification. Our findings suggested that TQ potentially affects interaction of d-ribose with Hb that prevents glycoxidation and protofibril formation, which establishes TQ as a potential therapeutic agent.
Asunto(s)
Benzoquinonas/farmacología , Fenómenos Biofísicos , Hemoglobinas/metabolismo , Fitoquímicos/farmacología , Benzotiazoles/metabolismo , Calorimetría , Dispersión Dinámica de Luz , Productos Finales de Glicación Avanzada/química , Productos Finales de Glicación Avanzada/metabolismo , Glicosilación/efectos de los fármacos , Hemoglobinas/química , Hemoglobinas/ultraestructura , Hidrodinámica , Interacciones Hidrofóbicas e Hidrofílicas , Simulación del Acoplamiento Molecular , Nefelometría y Turbidimetría , Agregado de Proteínas , Unión Proteica , Estructura Secundaria de Proteína , Ribosa/química , Espectrometría de Fluorescencia , TermodinámicaRESUMEN
A highly efficient and eco-friendly route for the reduction of graphene oxide (GO) to reduced graphene oxide (rGO) was developed by using polyvinylpyrrolidone coated CeO2 NPs (PVP-CeO2) as a reducing and stabilizing agent. The resulting carbonaceous material, PVP-CeO2/rGO, was well characterized with different spectroscopic techniques such as Fourier Transform Infrared (FTIR) spectroscopy, Scanning Electron Microscopy (SEM), Energy Dispersive X-ray (EDX), elemental mapping, Transmission Electron Microscopy (TEM), Raman spectroscopy, powder X-ray diffraction (XRD), Brunauer-Emmett-Teller (BET), X-ray Photoelectron Spectroscopy (XPS), and Thermal Gravimetric (TG) analyses. The material exhibited high catalytic potential towards multicomponent reactions for the synthesis of biologically relevant benzodiazepine derivatives in aqueous media. The efficiency of the material for the desired reaction was shown in the form of an excellent product yield (96-98%) and a very short reaction time period (7-10 min). The use of water as solvent and recyclability of the catalyst made the present protocol acceptable from a green perspective.
RESUMEN
A novel mesostructured catalyst sulphated alumina tungstic acid (SATA) has been prepared by an easy route. Various techniques such as IR, XRD, SEM, EDX, TEM, TGA and BET were used to characterize the synthesized catalyst. The catalytic activity of the meso material has been explored by synthesizing a series of new pyrazole carbonitrile derivatives from aromatic aldehydes, ethylcyanoacetate, phenylhydrazine/hydrazine hydrate in ethanol under reflux conditions. Furthermore, the "greenness" of this protocol when estimated by green metrics, displayed satisfactory results. The protocol is free from column chromatography, and toxic solvents and is more efficient as compared to reported ones.
RESUMEN
Silica modified imidazolium [smim] based halometallic ionic liquids, [smim][MCl4] (M = Fe, Cu and Zn), were synthesized for the evaluation of acidic and catalytic properties. Among these ILs, [smim][FeCl4]- was used for the preparation of heterogeneous catalyst ([smim][FeCl4]-@Nd2O3) by simple immobilization of IL on Nd2O3 nanoparticles. The structure of [smim][FeCl4]-@Nd2O3 was established by various techniques including FTIR, Raman, UV-vis DRS, powder XRD, SEM/EDX, elemental mapping, TEM, TGA, EPR and XPS analyses. The stability of nano-catalyst, [smim][ FeCl4]-@Nd2O3, was established with the help of zeta potential analysis which showed a value of -40.32 mV lying under the stability range. Potentiometric titration with n-butyl amine was used to evaluate the acidic properties of [smim][MCl4] as well as [smim][FeCl4]-@Nd2O3. The catalytic potential of the material was probed through the one pot synthesis of N-aryl indeno pyrrole derivatives. The results showed excellent performance of the material by producing a high yield (98%) of indeno pyrrole derivatives. A recyclability experiment revealed that the catalyst was efficient in up to five cycles with insignificant loss in catalytic activity. The evaluation of green metrics indicated the sustainability of the present protocol in terms of high atom economy and low E-factor.
RESUMEN
In the present study, we report the cooperative refolding/renaturation behaviour of guanidinium hydrochloride (GdnHCl) denatured bovine serum albumin (BSA) in the presence of cationic surfactant cetyltrimethylammonium bromide (CTAB), anionic surfactant sodium dodecyl sulphate (SDS) and their catanionic mixture in the solution of 60â¯mM sodium phosphate buffer of physiological pHâ¯7.4, using artificial chaperone-assisted two-step method. Here, we have employed biophysical techniques to characterize the refolding mechanism of denatured BSA after 200 times of dilution in the presence of cationic, anionic surfactants and their catanionic mixture, separately. We have found that minimum refolding of diluted BSA in the presence of 1:1 rational mixture of CTAB and SDS (CTAB/SDSâ¯=â¯50/50), it may be due to the micelles formation which is responsible for the unordered microstructure aggregate formation. Other mixtures (CTAB/SDSâ¯=â¯20/80 and 80/20) slightly played an effective role during refolding process in the presence of methyl-ß-cyclodextrin. On other hand, CTAB and SDS are more effective and reflect a good renaturation tendency of denatured BSA solution separately and in existence of methyl-ß-cyclodextrin as compare to their mixture compositions. But overall, CTAB has the better renaturation tendency as compare to SDS in the existence of methyl-ß-cyclodextrin. These results ascribed the presence of charge head group and length of hydrophobic tail of CTAB surfactant that plays an important task during electrostatic and hydrophobic interactions at pHâ¯7.4 at which BSA carries negative charge on their surface. These biophysical parameters suggest that, CTAB surfactant assisted artificial chaperone protocol may be utilized in the protein renaturation/refolding studies, which may address the associated problems of biotechnological industries for the development of efficient and inexpensive folding aides, which may also be used to produced genetically engineered cells related diseases, resulting from protein misfolding/aggregation.