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1.
Int J Mol Sci ; 25(4)2024 Feb 10.
Artigo em Inglês | MEDLINE | ID: mdl-38396842

RESUMO

Type 2 diabetes is characterized by hyperglycemia and a relative loss of ß-cell function. Our research investigated the antidiabetic potential of betulin, a pentacyclic triterpenoid found primarily in birch bark and, intriguingly, in a few marine organisms. Betulin has been shown to possess diverse biological activities, including antioxidant and antidiabetic activities; however, no studies have fully explored the effects of betulin on the pancreas and pancreatic islets. In this study, we investigated the effect of betulin on streptozotocin-nicotinamide (STZ)-induced diabetes in female Wistar rats. Betulin was prepared as an emulsion, and intragastric treatments were administered at doses of 20 and 50 mg/kg for 28 days. The effect of treatment was assessed by analyzing glucose parameters such as fasting blood glucose, hemoglobin A1C, and glucose tolerance; hepatic and renal biomarkers; lipid peroxidation; antioxidant enzymes; immunohistochemical analysis; and hematological indices. Administration of betulin improved the glycemic response and decreased α-amylase activity in diabetic rats, although insulin levels and homeostatic model assessment for insulin resistance (HOMA-IR) scores remained unchanged. Furthermore, betulin lowered the levels of hepatic biomarkers (aspartate aminotransferase, alanine aminotransferase, and alpha-amylase activities) and renal biomarkers (urea and creatine), in addition to improving glutathione levels and preventing the elevation of lipid peroxidation in diabetic animals. We also found that betulin promoted the regeneration of ß-cells in a dose-dependent manner but did not have toxic effects on the pancreas. In conclusion, betulin at a dose of 50 mg/kg exerts a pronounced protective effect against cytolysis, diabetic nephropathy, and damage to the acinar pancreas and may be a potential treatment option for diabetes.


Assuntos
Ácido Betulínico , Diabetes Mellitus Experimental , Diabetes Mellitus Tipo 2 , Ratos , Feminino , Animais , Antioxidantes/uso terapêutico , Niacinamida/farmacologia , Niacinamida/uso terapêutico , Ratos Wistar , Estreptozocina/efeitos adversos , Diabetes Mellitus Experimental/induzido quimicamente , Glicemia , Extratos Vegetais/farmacologia , Diabetes Mellitus Tipo 2/tratamento farmacológico , Hipoglicemiantes/efeitos adversos , Glucose/efeitos adversos , Biomarcadores , alfa-Amilases
2.
Nutrients ; 16(2)2024 Jan 12.
Artigo em Inglês | MEDLINE | ID: mdl-38257139

RESUMO

Circadian rhythm disruption is increasingly considered an environmental risk factor for the development and exacerbation of inflammatory bowel disease. We have reported in a previous study that nychthemeral dysregulation is associated with an increase in intestinal barrier permeability and inflammation in mice with dextran sulfate sodium (DSS)-induced colitis. To investigate the effect of circadian rhythm disruption on the composition and diversity of the gut microbiota (GM), sixty male C57BL/6J mice were initially divided to two groups, with the shifted group (n = 30) exposed to circadian shifts for three months and the non-shifted group (n = 30) kept under a normal light-dark cycle. The mice of the shifted group were cyclically housed for five days under the normal 12:12 h light-dark cycle, followed by another five days under a reversed light-dark cycle. At the end of the three months, a colitis was induced by 2% DSS given in the drinking water of 30 mice. Animals were then divided into four groups (n = 15 per group): sham group non-shifted (Sham-NS), sham group shifted (Sham-S), DSS non-shifted (DSS-NS) and DSS shifted (DSS-S). Fecal samples were collected from rectal content to investigate changes in GM composition via DNA extraction, followed by high-throughput sequencing of the bacterial 16S rRNA gene. The mouse GM was dominated by three phyla: Firmicutes, Bacteroidetes and Actinobacteria. The Firmicutes/Bacteroidetes ratio decreased in mice with induced colitis. The richness and diversity of the GM were reduced in the colitis group, especially in the group with inverted circadian rhythm. Moreover, the GM composition was modified in the inverted circadian rhythm group, with an increase in Alloprevotella, Turicibacter, Bacteroides and Streptococcus genera. Circadian rhythm inversion exacerbates GM dysbiosis to a less rich and diversified extent in a DSS-induced colitis model. These findings show possible interplay between circadian rhythm disruption, GM dynamics and colitis pathogenesis.


Assuntos
Colite , Microbioma Gastrointestinal , Masculino , Animais , Camundongos , Camundongos Endogâmicos C57BL , Sulfato de Dextrana/toxicidade , Disbiose , RNA Ribossômico 16S/genética , Colite/induzido quimicamente , Ritmo Circadiano , Bacteroidetes , Firmicutes
3.
Int J Mol Sci ; 24(18)2023 Sep 20.
Artigo em Inglês | MEDLINE | ID: mdl-37762647

RESUMO

Currently, the efficacy of drug therapy for post-traumatic stress disorder or PTSD leaves much to be desired, making nutraceutical support a promising avenue for treatment. Recent research has identified the protective effects of resveratrol in PTSD. Here, we tested the behavioral and neurobiological effects of combining cheese consumption with resveratrol supplements in an experimental PTSD model. Using the elevated plus maze test, we observed that cheese intake resulted in a shift from anxiety-like behavior to depressive behavior, evident in increased freezing acts. However, no significant changes in the anxiety index value were observed. Interestingly, supplementation with cheese and resveratrol only led to the elimination of freezing behavior in half of the PTSD rats. We further segregated the rats into two groups based on freezing behavior: Freezing+ and Freezing0 phenotypes. Resveratrol ameliorated the abnormalities in Monoamine Oxidize -A and Brain-Derived Neurotrophic Factor gene expression in the hippocampus, but only in the Freezing0 rats. Moreover, a negative correlation was found between the number of freezing acts and the levels of Monoamine Oxidize-A and Brain-Derived Neurotrophic Factor mRNAs in the hippocampus. The study results show promise for resveratrol supplementation in PTSD treatment. Further research is warranted to better understand the underlying mechanisms and optimize the potential benefits of resveratrol supplementation for PTSD.


Assuntos
Queijo , Transtornos de Estresse Pós-Traumáticos , Animais , Ratos , Transtornos de Estresse Pós-Traumáticos/tratamento farmacológico , Fator Neurotrófico Derivado do Encéfalo/genética , Resveratrol/farmacologia , Resveratrol/uso terapêutico , Aminas , Suplementos Nutricionais
4.
Biomolecules ; 13(7)2023 07 12.
Artigo em Inglês | MEDLINE | ID: mdl-37509141

RESUMO

Betulin is a natural triterpene, usually from birch bark, known for its potential wound-healing properties. Despite having a wide range of pharmacological targets, no studies have proposed betulin as a multitarget compound. Betulin has protective effects against cardiovascular and liver diseases, cancer, diabetes, oxidative stress, and inflammation. It reduces postprandial hyperglycemia by inhibiting α-amylase and α-glucosidase activity, combats tumor cells by inducing apoptosis and inhibiting metastatic proteins, and modulates chronic inflammation by blocking the expression of proinflammatory cytokines via modulation of the NFκB and MAPKs pathways. Given its potential to influence diverse biological networks with high target specificity, it can be hypothesized that betulin may eventually become a new lead for drug development because it can modify a variety of pharmacological targets. The summarized research revealed that the diverse beneficial effects of betulin in various diseases can be attributed, at least in part, to its multitarget anti-inflammatory activity. This review focuses on the natural sources, pharmacokinetics, pharmacological activity of betulin, and the multi-target effects of betulin on signaling pathways such as MAPK, NF-κB, and Nrf2, which are important regulators of the response to oxidative stress and inflammation in the body.


Assuntos
Triterpenos , Humanos , Triterpenos/farmacologia , Ácido Betulínico , Citocinas/metabolismo , Inflamação/tratamento farmacológico , NF-kappa B/metabolismo
5.
Int J Mol Sci ; 24(11)2023 May 26.
Artigo em Inglês | MEDLINE | ID: mdl-37298287

RESUMO

Glucocorticoids are metabolized by the CYP3A isoform of cytochrome P450 and by 11-ß-hydroxysteroid dehydrogenase type 1 (11ß-HSD-1). Experimental data suggest that post-traumatic stress disorder (PTSD) is associated with an increase in hepatic 11ß-HSD-1 activity and a concomitant decrease in hepatic CYP3A activity. Trans-resveratrol, a natural polyphenol, has been extensively studied for its antipsychiatric properties. Recently, protective effects of trans-resveratrol were found in relation to PTSD. Treatment of PTSD rats with trans-resveratrol allowed the rats to be divided into two phenotypes. The first phenotype is treatment-sensitive rats (TSR), and the second phenotype is treatment-resistant rats (TRRs). In TSR rats, trans-resveratrol ameliorated anxiety-like behavior and reversed plasma corticosterone concentration abnormalities. In contrast, in TRR rats, trans-resveratrol aggravated anxiety-like behavior and decreased plasma corticosterone concentration. In TSR rats, hepatic 11ß-HSD-1 activity was suppressed, with a concomitant increase in CYP3A activity. In TRR rats, the activities of both enzymes were suppressed. Thus, the resistance of PTSD rats to trans-resveratrol treatment is associated with abnormalities in hepatic metabolism of glucocorticoids. The free energy of binding of resveratrol, cortisol, and corticosterone to the human CYP3A protein was determined using the molecular mechanics Poisson-Boltzmann surface area approach, indicating that resveratrol could affect CYP3A activity.


Assuntos
Glucocorticoides , Transtornos de Estresse Pós-Traumáticos , Ratos , Humanos , Animais , Glucocorticoides/farmacologia , Glucocorticoides/metabolismo , Corticosterona , Resveratrol/farmacologia , Transtornos de Estresse Pós-Traumáticos/tratamento farmacológico , Citocromo P-450 CYP3A , 11-beta-Hidroxiesteroide Desidrogenases , Hidroxiesteroide Desidrogenases/genética , Hidroxiesteroide Desidrogenases/metabolismo , 11-beta-Hidroxiesteroide Desidrogenase Tipo 1
6.
Mar Drugs ; 21(5)2023 Apr 23.
Artigo em Inglês | MEDLINE | ID: mdl-37233457

RESUMO

Phlorotannins are secondary metabolites produced mainly by brown seaweeds (Phaeophyceae) and belong to the class of polyphenolic compounds with diverse bioactivities. The key factors in the extraction of polyphenols are the selection of a suitable solvent, method of extraction and selection of optimal conditions. Ultrasonic-assisted extraction (UAE) is one of the advanced energy-saving methods suitable for the extraction of labile compounds. Methanol, acetone, ethanol and ethyl acetate are the most commonly used solvents for polyphenol extraction. As alternatives to toxic organic solvents, a new class of green solvents, natural deep eutectic solvents (NADES), has been proposed for the efficient extraction of a wide range of natural compounds including polyphenols. Several NADES were screened previously for the extraction of phlorotannins; however, the extraction conditions were not optimized and chemical profiling of NADES extract was not performed. The purpose of this work was to study the effect of selected extraction parameters on the phlorotannin content in NADES extract from Fucus vesiculosus, optimization of extraction conditions and chemical profiling of phlorotannins in the NADES extract. A fast and green NADES-UAE procedure was developed for the extraction of phlorotannins. Optimization was performed through an experimental design and showed that NADES (lactic acid:choline chloride; 3:1) provides a high yield (137.3 mg phloroglucinol equivalents per g dry weight of algae) of phlorotannins under the following extraction conditions: extraction time 23 min, 30.0% water concentration and 1:12 sample to solvent ratio. The antioxidant activity of the optimized NADES extract was equal to that of EtOH extract. In total, 32 phlorotannins have been identified (one trimer, two tetramers, six pentamers, four hexamers, six heptamers, six octamers and seven nonamers) in NADES extracts from arctic F. vesiculosus using the HPLC-HRMS and MS/MS technique. It was noted that all the above-mentioned phlorotannins were identified in both EtOH and NADES extracts. Our results suggest that NADES could be considered as an alternative to the conventional techniques for the effective extraction of phlorotannins from F. vesiculosus with high antioxidant potential.


Assuntos
Fucus , Espectrometria de Massas em Tandem , Solventes Eutéticos Profundos , Fucus/química , Cromatografia Líquida de Alta Pressão/métodos , Extratos Vegetais/química , Solventes/química
7.
Crit Rev Food Sci Nutr ; 63(2): 261-287, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-34251921

RESUMO

Isoflavones are secondary metabolites that represent the most abundant category of plant polyphenols. Dietary soy, kudzu, and red clover contain primarily genistein, daidzein, glycitein, puerarin, formononetin, and biochanin A. The structural similarity of these compounds to ß-estradiol has demonstrated protection against age-related and hormone-dependent diseases in both genders. Demonstrative shreds of evidence confirmed the fundamental health benefits of the consumption of these isoflavones. These relevant activities are complex and largely driven by the source, active ingredients, dose, and administration period of the bioactive compounds. However, the preclinical and clinical studies of these compounds are greatly variable, controversial, and still with no consensus due to the non-standardized research protocols. In addition, absorption, distribution, metabolism, and excretion studies, and the safety profile of isoflavones have been far limited. This highlights a major gap in understanding the potentially critical role of these isoflavones as prospective replacement therapy. Our general review exclusively focuses attention on the crucial role of isoflavones derived from these plant materials and critically highlights their bioavailability, possible anticancer, antiaging potentials, and microbiome modulation. Despite their fundamental health benefits, plant isoflavones reveal prospective therapeutic effects that worth further standardized analysis.


Assuntos
Feminino , Masculino , Humanos
8.
Chem Commun (Camb) ; 58(66): 9278-9281, 2022 Aug 16.
Artigo em Inglês | MEDLINE | ID: mdl-35904069

RESUMO

The rapid extraction of high-purity nucleic acids from complex biological samples using conventional methods is complicated. Therefore, in this study, glycine-pillar[6]arene (Gly-P6)-functionalized tapered nanochannels were constructed using 32-mer single-stranded E. coli DNA (ssDNA) as a model sequence, which can selectively transport ssDNA by multiple noncovalent forces (transport flux of 2.65 nM cm-2 h-1) under the interference of amino acids and other substances. In view of these prospective results, the selective transport of nucleic acids with nanochannels could be applied in the design of nucleic acid enrichment and separation systems in the future.


Assuntos
Ácidos Nucleicos , DNA de Cadeia Simples , Escherichia coli , Estudos Prospectivos , Compostos de Amônio Quaternário
9.
Appl Microbiol Biotechnol ; 106(9-10): 3531-3538, 2022 May.
Artigo em Inglês | MEDLINE | ID: mdl-35579685

RESUMO

Astaxanthin is an important ketocarotenoid with remarkable biological activities and high economic value. In recent times, natural astaxanthin production by microorganisms has attracted much attention particularly in pharmaceuticals, nutraceuticals, cosmetics, and food and feed industries. Though, currently, productivity is still low and has restricted scale-up application in the commercial market, microbial production of astaxanthin has enormous prospects as it is a greener alternative to the predominating chemical synthesis. Over the years, Phaffia rhodozyma has attracted immense interest particularly in the field of biovalorization and sustainable production of natural nutraceuticals as a promising source of natural astaxanthin since it is able to use agro-food waste as inexpensive nutrient source. Many research works have, thus, been devoted to improving the astaxanthin yield from this yeast. Considering that the yeast was first isolated from tree exudates, the use of phytohormones and plant growth stimulators as prospective stimulants of astaxanthin production in the yeast is promising. Besides, it has been shown in several studies that phytohormones could improve cell growth and astaxanthin production of algae. Nevertheless, this option is less explored for P. rhodozyma. The few studies that have examined the effect of phytohormones on the yeast and its astaxanthin productivity reported positive results, with phytohormones such as 6-benzylaminopurin and gibberellic acid resulting in increased expression of carotenogenesis genes. Although the evidence available is scanty, the results are promising. KEY POINTS: • Phaffia rhodozyma is a promising source of natural astaxanthin • For industrialization, astaxanthin productivity of P. rhodozyma still needs optimization • Phytohormones could potentially augment astaxanthin yield of P. rhodozyma.


Assuntos
Basidiomycota , Eliminação de Resíduos , Basidiomycota/metabolismo , Alimentos , Reguladores de Crescimento de Plantas/metabolismo , Estudos Prospectivos , Saccharomyces cerevisiae , Xantofilas
10.
Plants (Basel) ; 11(6)2022 Mar 10.
Artigo em Inglês | MEDLINE | ID: mdl-35336625

RESUMO

Pediatric solid tumors (PSTs) are life-threatening and can lead to high morbidity and mortality rates in children. Developing novel remedies to treat these tumors, such as glioblastoma multiforme and sarcomas, such as osteosarcoma, and rhabdomyosarcoma, is challenging, despite immense attempts with chemotherapeutic or radiotherapeutic interventions. Soy (Glycine max) and kudzu roots (KR) (Pueraria spp.) are well-known phytoestrogenic botanical sources that contain high amounts of naturally occurring isoflavones. In the present study, we investigated the antioxidant and cytotoxic effects of the extracts of KR and soy molasses (SM) against PSTs. The green extraction of isoflavones from KR and SM was performed using natural deep eutectic solvents. The extracts were subsequently analyzed by high-performance liquid chromatography (HPLC)-diode array detector (DAD) coupled with high-resolution (HR) mass spectrometry (MS), which identified 10 isoflavones in KR extracts and 3 isoflavones in the SM extracts. Antioxidant and cytotoxic activities of KR and SM extracts were assessed against glioblastoma multiforme (A-172), osteosarcoma (HOS), and rhabdomyosarcoma (Rd) cancer cell lines. The KR and SM extracts showed satisfactory cytotoxic effects (IC50) against the cancer cell lines tested, particularly against Rd cancer cell lines, in a dose-dependent manner. Antioxidant activity was found to be significantly (p ≤ 0.05) higher in KR than in SM, which was consistent with the results of the cytotoxic activity observed with KR and SM extracts against glioblastoma and osteosarcoma cells. The total flavonoid content and antioxidant activities of the extracts were remarkably attributed to the isoflavone content in the KR and SM extracts. This study provides experimental evidence that HPLC-ESI-HRMS is a suitable analytical approach to identify isoflavones that exhibit potent antioxidant and anticancer potential against tumor cells, and that KR and SM, containing many isoflavones, can be a potential alternative for health care in the food and pharmaceutical industries.

11.
Int J Mol Sci ; 23(4)2022 Feb 21.
Artigo em Inglês | MEDLINE | ID: mdl-35216511

RESUMO

The modification of chitosan represents a challenging task in obtaining biopolymeric materials with enhanced removal capacity for heavy metals. In the present work, the adsorption characteristics of chitosan modified with carboxyl groups (CTS-CAA) towards copper (II) and zinc (II) ions have been tested. The efficacy of the synthesis of CTS-CAA has been evaluated by studying various properties of the modified chitosan. Specifically, the functionalized chitosan has been characterized by using several techniques, including thermal analyses (differential scanning calorimetry and thermogravimetry), spectroscopies (FT-IR, XRD), elemental analysis, and scanning electron microscopy. The kinetics and the adsorption isotherms of CTS-CAA towards both Cu (II) and Zn (II) have been determined in the aqueous solvent under variable pH. The obtained results have been analyzed by using different adsorption models. In addition, the experiments have been conducted at variable temperatures to explore the thermodynamics of the adsorption process. The regeneration of CTS-CAA has been investigated by studying the desorption process using different eluents. This paper reports an efficient protocol to synthesize chitosan-based material perspective as regenerative adsorbents for heavy metals.


Assuntos
Materiais Biocompatíveis/química , Quitosana/química , Cobre/química , Íons/química , Água/química , Zinco/química , Adsorção , Concentração de Íons de Hidrogênio , Cinética , Espectroscopia de Infravermelho com Transformada de Fourier/métodos , Termodinâmica , Poluentes Químicos da Água/química , Purificação da Água/métodos
12.
Chem Commun (Camb) ; 58(20): 3255-3269, 2022 Mar 08.
Artigo em Inglês | MEDLINE | ID: mdl-35195641

RESUMO

Stimuli-responsive nanosystems have attracted the interest of researchers due to their intelligent function of controlled release regulated by a variety of external stimuli and have been applied in biomedical fields. Pillar[n]arenes with the advantages of a rigid structure, electron holes and easy functionalization are considered as excellent candidates for the construction of host-guest nanosystems. In recent years, many pillararene modified nanosystems have been reported in response to different stimuli. In this feature article, we summarize the advance of stimuli-responsive pillararene modified nanosystems for controlled release of drugs from the perspectives of decomposition release and gated release, focusing on the control principles of these nanosystems. We expect that this review can enlighten and guide investigators in the field of stimuli-responsive controlled release.

13.
Crit Rev Food Sci Nutr ; 62(18): 5005-5028, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-33591215

RESUMO

Diabetes remains a major health emergency in our entire world, affecting hundreds of millions of people worldwide. In conjunction with its much-dreaded complications (e.g., nephropathy, neuropathy, retinopathy, cardiovascular diseases, etc.) it substantially reduces the quality of life, increases mortality as well as economic burden among patients. Over the years, oxidative stress and inflammation have been highlighted as key players in the development and progression of diabetes and its associated complications. Much research has been devoted, as such, to the role of antioxidants in diabetes. Astaxanthin is a powerful antioxidant found mostly in marine organisms. Over the past years, several studies have demonstrated that astaxanthin could be useful in the treatment and management of diabetes. It has been shown to protect ß-cells, neurons as well as several organs including the eyes, kidney, liver, etc. against oxidative injuries experienced during diabetes. Furthermore, it improves glucose and lipid metabolism along with cardiovascular health. Its beneficial effects are exerted through multiple actions on cellular functions. Considering these and the fact that foods and natural products with biological and pharmacological activities are of much interest in the 21st-century food and drug industry, astaxanthin has a bright prospect in the management of diabetes and its complications.


Assuntos
Antioxidantes , Diabetes Mellitus , Antioxidantes/farmacologia , Antioxidantes/uso terapêutico , Diabetes Mellitus/tratamento farmacológico , Humanos , Estresse Oxidativo , Qualidade de Vida , Xantofilas/farmacologia , Xantofilas/uso terapêutico
14.
Int Immunopharmacol ; 101(Pt A): 108204, 2021 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-34619497

RESUMO

Acute lung injury (ALI) is a life-threatening syndrome that possibly leads to high morbidity and mortality as no therapy exists. Several natural ingredients with negligible adverse effects have recently been investigated to possibly inhibit the inflammatory pathways associated with ALI at the molecular level. Isoflavones, as phytoestrogenic compounds, are naturally occurring bioactive compounds that represent the most abundant category of plant polyphenols (Leguminosae family). A broad range of therapeutic activities of isoflavones, including antioxidants, chemopreventive, anti-inflammatory, antiallergic and antibacterial potentials, have been extensively documented in the literature. Our review exclusively focuses on the possible anti-inflammatory, antioxidant role of botanicals'-derived isoflavones against ALI and their immunomodulatory effect in experimentally induced ALI. Despite the limited scope covering their molecular mechanisms, isoflavones substantially contributed to protecting from ALI via inhibiting toll-like receptor 4 (TLR4)/Myd88/NF-κB pathway and subsequent cytokines, chemokines, and adherent proteins. Nonetheless, future research is suggested to fill the gap in elucidating the protective roles of isoflavones to alleviate ALI concerning antioxidant potentials, inhibition of the inflammatory pathways, and associated molecular mechanisms.


Assuntos
Lesão Pulmonar Aguda/tratamento farmacológico , Anti-Inflamatórios/uso terapêutico , Isoflavonas/uso terapêutico , Extratos Vegetais/uso terapêutico , Animais , Anti-Inflamatórios/isolamento & purificação , Humanos , Isoflavonas/isolamento & purificação , Extratos Vegetais/isolamento & purificação
15.
Gels ; 7(3)2021 Aug 11.
Artigo em Inglês | MEDLINE | ID: mdl-34449616

RESUMO

The binary xerogels TiO2-SiO2 are widely used as catalysts and their carriers in organic synthesis. Characterization and adjustment of the electrostatic properties of the surface and the local acidity inside the pores, are necessary for the further development of TiO2-SiO2 xerogels applications. This research investigates acid-base equilibria in the pores, and the surface electrostatic potential (SEP) of binary TiO2-SiO2 xerogels, by the EPR of stable pH-sensitive nitroxide radicals. These radicals are small enough to penetrate directly into the pores, and to be adsorbed onto the surface of the material under study. This makes it possible to obtain valuable information on the acidic and electrosurface properties of the studied system. The highest negative surface electrical charge associated with surface electrical potential (SEP) was equal to -196 ± 6 mV. It was induced by the surface of the sample with a 7% TiO2 content. The local acidity inside the pores of this sample was found to be higher, by approximately 1.49 pH units, as compared to that in the external bulk solution.

16.
Chem Commun (Camb) ; 57(61): 7480-7492, 2021 Aug 07.
Artigo em Inglês | MEDLINE | ID: mdl-34264255

RESUMO

Chiral discrimination has gained much focus in supramolecular chemistry, since it is one of the fundamental processes in biological systems, enantiomeric separation and biochemical sensors. Though most of the biochemical processes can routinely recognize biological enantiomers, enantioselective identification of chiral molecules in artificial systems is currently one of the challenging topics in the field of chiral discrimination. Inaccuracy, low separation efficiency and expensive instrumentation were considered typical problems in artificial systems. Recently, chiral recognition on the interfaces has been widely used in the fields of electrochemical detection and biochemical sensing. For the moment, a series of macrocyclic host functionalized interfaces have been developed for use as chiral catalysts or for enantiomeric separation. Here, we have briefly exposited the most recent advances in the fabrication of supramolecular functionalized interfaces and their application for chiral recognition.


Assuntos
Calixarenos/química , Éteres de Coroa/química , Ciclodextrinas/química , Polímeros/química , Ligantes , Estereoisomerismo
17.
Int J Biol Macromol ; 139: 153-160, 2019 Oct 15.
Artigo em Inglês | MEDLINE | ID: mdl-31356952

RESUMO

A new adsorbent, sulfated crosslinked chitosan (SGCH), has been synthesized for the effective extraction of beryllium ions from their aqueous solutions. In recent times, beryllium extraction has been of great importance because beryllium can be used in many applications such as in nuclear reactor, heat shields, high-technology ceramics, alloys and electronic heat sinks. SGCH has been synthesized by two successive phases. The first is the conversion of chitosan (CH) into non-soluble cross-linked chitosan (GCH) through the interaction between chitosan and glutaraldehyde. The second step is the formation of functional sulfonate groups onto the adsorbent material through the interaction of GCH with chlorosulfonic acid (sulfating agent). The role played by the sulfonate groups in the adsorption process was analyzed using FT-IR and SEM. Also, the role played by the solution pH, time, beryllium concentration and temperature on the batch adsorption process was investigated. Our results point to the successful preparation of SGCH adsorbent with high affinity for beryllium ions. The maximum sorption values of beryllium ions on the investigated biosorbent is 40.6 mg/g. The desorption of the loaded beryllium ions from the SGCH was achieved by using 1.5 M urea acidified by 0.6 M H2SO4.


Assuntos
Berílio/química , Berílio/isolamento & purificação , Quitosana/química , Quitosana/síntese química , Ácidos Sulfônicos/química , Adsorção , Técnicas de Química Sintética , Fatores de Tempo
18.
Phytother Res ; 33(8): 1966-1980, 2019 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-31209936

RESUMO

The use of mushrooms as functional foods and in the treatment of diseases has a long history. Inonotus obliquus is a mushroom belonging to the Hymenochaetaceae family and has possible anticancer, antiviral, and hypoglycemic properties. Chemical analysis of this mushroom has allowed the identification of various constituents such as melanins, phenolic compounds, and lanostane-type triterpenoids. A plethora of findings have highlighted the potential molecular mechanisms of actions of this mushroom such as its ability to scavenge reactive oxygen species, inhibit the growth of tumors, decrease inflammation and insulin resistance in type 2 diabetes, and stimulate the immune system. This review summarizes the relevant findings with reference to the therapeutic potential of this mushroom in countering the progression of cancers, diabetes mellitus, and antiviral activities, while highlighting its possible molecular mechanisms of action. The possible role of this mushroom as a therapeutic agent in addressing the pathogenesis of diabetes and cancer has also been suggested.


Assuntos
Agaricales/química , Diabetes Mellitus Tipo 2/tratamento farmacológico , Hipoglicemiantes/uso terapêutico , Neoplasias/tratamento farmacológico , Animais , Humanos , Hipoglicemiantes/farmacologia , Camundongos , Ratos
20.
Sci Rep ; 7: 44628, 2017 03 16.
Artigo em Inglês | MEDLINE | ID: mdl-28300169

RESUMO

Serial femtosecond crystallography requires reliable and efficient delivery of fresh crystals across the beam of an X-ray free-electron laser over the course of an experiment. We introduce a double-flow focusing nozzle to meet this challenge, with significantly reduced sample consumption, while improving jet stability over previous generations of nozzles. We demonstrate its use to determine the first room-temperature structure of RNA polymerase II at high resolution, revealing new structural details. Moreover, the double-flow focusing nozzles were successfully tested with three other protein samples and the first room temperature structure of an extradiol ring-cleaving dioxygenase was solved by utilizing the improved operation and characteristics of these devices [corrected].


Assuntos
Cristalografia/instrumentação , Reologia/instrumentação , Simulação por Computador , RNA Polimerase II/química , Saccharomyces cerevisiae/enzimologia , Temperatura , Fatores de Tempo , Difração de Raios X
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