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Rapid evolution of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) and influenza A virus (IAV) poses enormous challenge in the development of broad-spectrum antivirals that are effective against the existing and emerging viral strains. Virus entry through endocytosis represents an attractive target for drug development, as inhibition of this early infection step should block downstream infection processes, and potentially inhibit viruses sharing the same entry route. In this study, we report the identification of 1,3-diphenylurea (DPU) derivatives (DPUDs) as a new class of endocytosis inhibitors, which broadly restricted entry and replication of several SARS-CoV-2 and IAV strains. Importantly, the DPUDs did not induce any significant cytotoxicity at concentrations effective against the viral infections. Examining the uptake of cargoes specific to different endocytic pathways, we found that DPUDs majorly affected clathrin-mediated endocytosis, which both SARS-CoV-2 and IAV utilize for cellular entry. In the DPUD-treated cells, although virus binding on the cell surface was unaffected, internalization of both the viruses was drastically reduced. Since compounds similar to the DPUDs were previously reported to transport anions including chloride (Cl-) across lipid membrane and since intracellular Cl- concentration plays a critical role in regulating vesicular trafficking, we hypothesized that the observed defect in endocytosis by the DPUDs could be due to altered Cl- gradient across the cell membrane. Using in vitro assays we demonstrated that the DPUDs transported Cl- into the cell and led to intracellular Cl- accumulation, which possibly affected the endocytic machinery by perturbing intracellular Cl- homeostasis. Finally, we tested the DPUDs in mice challenged with IAV and mouse-adapted SARS-CoV-2 (MA 10). Treatment of the infected mice with the DPUDs led to remarkable body weight recovery, improved survival and significantly reduced lung viral load, highlighting their potential for development as broad-spectrum antivirals.
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COVID-19 , Vírus da Influenza A , Animais , Camundongos , SARS-CoV-2 , Vírus da Influenza A/fisiologia , Endocitose , Internalização do Vírus , Antivirais/farmacologia , Antivirais/químicaRESUMO
IMPORTANCE: The Omicron subvariants have substantially evaded host-neutralizing antibodies and adopted an endosomal route of entry. The virus has acquired several mutations in the receptor binding domain and N-terminal domain of S1 subunit, but remarkably, also incorporated mutations in S2 which are fixed in Omicron sub-lineage. Here, we found that the mutations in the S2 subunit affect the structural and biological properties such as neutralization escape, entry route, fusogenicity, and protease requirement. In vivo, these mutations may have significant roles in tropism and replication. A detailed understanding of the effects of S2 mutations on Spike function, immune evasion, and viral entry would inform the vaccine design, as well as therapeutic interventions aiming to block the essential proteases for virus entry. Thus, our study has identified the crucial role of S2 mutations in stabilizing the Omicron spike and modulating neutralization resistance to antibodies targeting the S1 subunit.
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COVID-19 , SARS-CoV-2 , Glicoproteína da Espícula de Coronavírus , Humanos , Anticorpos Neutralizantes , Anticorpos Antivirais , Endopeptidases , Conformação Molecular , Mutação , Peptídeo Hidrolases , SARS-CoV-2/classificação , SARS-CoV-2/genética , Glicoproteína da Espícula de Coronavírus/genéticaRESUMO
Protein tertiary structure mimetics are valuable tools to target large protein-protein interaction interfaces. Here, we demonstrate a strategy for designing dimeric helix-hairpin motifs from a previously reported three-helix-bundle miniprotein that targets the receptor-binding domain (RBD) of severe acute respiratory syndrome-coronavirus-2 (SARS-CoV-2). Through truncation of the third helix and optimization of the interhelical loop residues of the miniprotein, we developed a thermostable dimeric helix-hairpin. The dimeric four-helix bundle competes with the human angiotensin-converting enzyme 2 (ACE2) in binding to RBD with 2:2 stoichiometry. Cryogenic-electron microscopy revealed the formation of dimeric spike ectodomain trimer by the four-helix bundle, where all the three RBDs from either spike protein are attached head-to-head in an open conformation, revealing a novel mechanism for virus neutralization. The proteomimetic protects hamsters from high dose viral challenge with replicative SARS-CoV-2 viruses, demonstrating the promise of this class of peptides that inhibit protein-protein interaction through target dimerization.
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Enzima de Conversão de Angiotensina 2 , COVID-19 , Dimerização , Humanos , Peptídeos/metabolismo , Peptidil Dipeptidase A/química , Peptidil Dipeptidase A/metabolismo , Ligação Proteica , SARS-CoV-2 , Glicoproteína da Espícula de Coronavírus/química , Glicoproteína da Espícula de Coronavírus/metabolismoRESUMO
Penile inversion vaginoplasty (PIV) is a gender-affirming surgical procedure where the skin of the penis and scrotum is reconstructed into the neovaginal lining. To prevent hair-bearing skin from becoming incorporated into the neovaginal canal, transgender patients are encouraged to undergo hair removal of their external genitalia. The goal of this preoperative hair removal is to minimize the risk of potential hair-related complications after vaginoplasty. To better support patients seeking preoperative hair removal and identify current treatment barriers, we surveyed patients about their progress and satisfaction with hair removal. A cross-sectional survey was constructed to assess patient experiences with hair removal in advance of PIV. Sixty-seven patients met the inclusion criteria, of which 46 participated (68.7%). Both laser hair removal (LHR) and electrolysis were used. Although all patients had completed some preoperative hair removal at the time of survey (average of 14 sessions), the cohort completed only two-thirds of their total expected hair clearance. Multiple peri-procedural pain management therapies were employed, but overall satisfaction with pain management was low (57.4 ± 5.0 out of 100). LHR was associated with significantly lower procedural pain compared to electrolysis (p < .001). The average global satisfaction with the hair removal process was 57.9 ± 5.7 and incidents of mistreatment were associated with a statistically significant reduction in overall satisfaction (p = .02). Most patients felt that hair removal was important prior to surgery. Overall, LHR and electrolysis were both utilized as effective preoperative hair removal modalities; however, LHR has better pain tolerability than electrolysis.
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Remoção de Cabelo , Satisfação do Paciente , Pênis , Humanos , Remoção de Cabelo/métodos , Masculino , Feminino , Adulto , Pênis/cirurgia , Estudos Transversais , Vagina/cirurgia , Cirurgia de Readequação Sexual/métodos , Pessoa de Meia-Idade , Adulto Jovem , Cuidados Pré-Operatórios/métodosRESUMO
INTRODUCTION: Epidermolysis bullosa (EB) encompasses rare hereditary skin conditions marked by skin fragility, nail dystrophy, and minor trauma-induced skin blisters. This study aims to identify genetic variants in Indian EB patients and examine the relationship between genotypic and phenotypic manifestations. MATERIAL AND METHOD: EB patients seen consecutively over a period of 5â years at Outpatient Department of Dermatology. Baseline demographic data, birth history, family history, skin manifestation at birth, past medical history, current cutaneous manifestations, and the evolution of the disease were assessed and recorded. Genetic variants were identified using targeted gene panel sequencing of 23 EB-related genes, and a genetic-phenotype analysis was performed. RESULTS: Our study included 65 patients with EB. Among 65 EB patients, 38 dystrophic EB cases (58.46%), 12 junctional EB (18.46%), 12 epidermolysis bullosa simplex (18.46%), and 3 Kindler EB (4.62%) were reported. Dominant and recessive forms of dystrophic EB accounted for 16.92% and 41.4%, respectively. We identified 75 unique genetic variants, 58.67% newly discovered and 41.33% previously reported. Compound heterozygous variations were more frequent (55.55%) than homozygous ones (44.44%) in recessive dystrophic EB patients. Junctional EB patients harboured LAMB3 gene mutations more frequently, while epidermolysis bullosa simplex patients showed KRT5 and KRT14 gene missense heterozygous mutations. Kindler EB patients had homozygous mutations in the FERTM1 gene. CONCLUSION: Our study unveiled several novel genetic variants; severe phenotypes associated with nonsense genetic variants. These findings offer valuable insights for future clinical assessments and tailored management strategies.
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Continuous Emission Monitoring Systems (CEMS) are devices used to measure and report real-time emission of air pollutants. Although CEMS have been extensively deployed in developed countries to ensure compliance with emission standards and enhance their environmental performance, their adoption in India is still in its early stages. The present study aims to evaluate the effectiveness of CEMS in India, identify obstacles in terms of policy, regulation, technology and finance that impede their adoption and suggest mechanisms and incentives to facilitate their expansion. The findings indicate that CEMS offer benefits for air pollution control in India by improving monitoring accuracy, transparency, accountability and enforcement. The study also highlights institutional challenges faced by CEMS, including the absence of a certification system, lack of quality assurance measures, issues with data validation and challenges in its calibration as well as integration concerns with existing regulatory framework. To address these challenges effectively it is recommended that India must develop a policy framework for CEMS along with regulations. Essential steps such as establishing a certification and accreditation system should be taken while enhancing stakeholders' capacity and awareness.
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Poluentes Atmosféricos , Poluição do Ar , Monitoramento Ambiental , Índia , Poluição do Ar/prevenção & controle , Poluição do Ar/análise , Monitoramento Ambiental/métodos , Poluentes Atmosféricos/análiseRESUMO
Background: Nontraumatic brain injury encompasses various pathological processes and medical conditions that result in brain dysfunction and neurological impairment without direct physical trauma. The study aimed to assess the efficacy of intravenous administration of 20% mannitol and 3% hypertonic saline to reduce intracranial pressure in nontraumatic brain injury. Materials and methods: The Preferred Reporting Items for Systematic Reviews and Meta-Analysis guidelines were followed for study selection and data extraction. The search was conducted in the PubMed, Embase, and Scopus databases, including articles published in English from January 2003 to December 2023. Our study included randomized controlled trials, comparative studies, prospective analyses, and retrospective cohort studies. We extracted data on baseline characteristics of patients, intervention details, major outcomes, and complications. Quality assessment was performed using the Jadad scale and the Robvis assessment tool for risk of bias. Results: A total of 14 studies involving 1,536 patients were included in the analysis. Seven studies reported hypertonic saline as more effective in reducing intracranial pressure, while three studies found similar effectiveness for both interventions. Adverse events were reported in only three studies. The studies that reported complication rates ranged from 21 to 79%. A meta-analysis was conducted on five studies, showing varying rates of adverse events associated with mannitol and hypertonic saline. Conclusion: Both hypertonic saline solution and mannitol have been explored as treatment options for decreasing intracranial pressure in nontraumatic brain injuries. While some studies indicate the superiority of hypertonic saline, others report similar effectiveness between the two interventions. How to cite this article: Choudhury A, Ravikant, Bairwa M, Jithesh G, Kumar S, Kumar N. Efficacy of Intravenous 20% Mannitol vs 3% Hypertonic Saline in Reducing Intracranial Pressure in Nontraumatic Brain Injury: A Systematic Review and Meta-analysis. Indian J Crit Care Med 2024;28(7):686-695.
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Transition metal phosphides (TMP) posses unique physiochemical, geometrical, and electronic properties, which can be exploited for different catalytic applications, such as photocatalysis, electrocatalysis, organic catalysis, etc. Among others, the use of TMP for organic catalysis is less explored and still facing many complex challenges, which necessitate the development of sustainable catalytic reaction protocols demonstrating high selectivity and yield of the desired molecules of high significance. In this regard, the controlled synthesis of TMP-based catalysts and thorough investigations of underlying reaction mechanisms can provide deeper insights toward practical achievement of desired applications. This review aims at providing a comprehensive analysis on the recent advancements in the synthetic strategies for the tailored and tunable engineering of structural, geometrical, and electronic properties of TMP. In addition, their unprecedented catalytic potential toward different organic transformation reactions is succinctly summarized and critically analyzed. Finally, a rational perspective on future opportunities and challenges in the emerging field of organic catalysis is provided. On the account of the recent achievements accomplished in organic synthesis using TMP, it is highly anticipated that the use of TMP combined with advanced innovative technologies and methodologies can pave the way toward large scale realization of organic catalysis.
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AIM: This study was aimed to determine antimicrobial and antiviral activity of a novel lanthipeptide from a Brevibacillus sp. for disinfectant application. METHODS AND RESULTS: The antimicrobial peptide (AMP) was produced by a bacterial strain AF8 identified as a member of the genus Brevibacillus representing a novel species. Whole genome sequence analysis using BAGEL identified a putative complete biosynthetic gene cluster involved in lanthipeptide synthesis. The deduced amino acid sequence of lanthipeptide named as brevicillin, showed >30% similarity with epidermin. Mass determined by MALDI-MS and Q-TOF suggested posttranslational modifications like dehydration of all Ser and Thr amino acids to yield Dha and Dhb, respectively. Amino acid composition determined upon acid hydrolysis is in agreement with core peptide sequence deduced from the putative biosynthetic gene bvrAF8. Biochemical evidence along with stability features ascertained posttranslational modifications during formation of the core peptide. The peptide showed strong activity with 99% killing of pathogens at 12 µg ml-1 within 1 minute. Interestingly, it also showed potent anti-SARS-CoV-2 activity by inhibiting â¼99% virus growth at 10 µg ml-1 in cell culture-based assay. Brevicillin did not show dermal allergic reactions in BALB/c mice. CONCLUSION: This study provides detailed description of a novel lanthipeptide and demonstrates its effective antibacterial, antifungal and anti-SARS-CoV-2 activity.
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Brevibacillus , COVID-19 , Animais , Camundongos , Antifúngicos/farmacologia , Antifúngicos/metabolismo , Brevibacillus/genética , Brevibacillus/metabolismo , Antivirais , Peptídeos/químicaRESUMO
Resistance to androgen deprivation therapy, or castration-resistant prostate cancer (CRPC), is often accompanied by metastasis and is currently the ultimate cause of prostate cancer-associated deaths in men. Recently, secondary hormonal therapies have led to an increase of neuroendocrine prostate cancer (NEPC), a highly aggressive variant of CRPC. Here, we identify that high levels of cell surface receptor Trop2 are predictive of recurrence of localized prostate cancer. Moreover, Trop2 is significantly elevated in CRPC and NEPC, drives prostate cancer growth, and induces neuroendocrine phenotype. Overexpression of Trop2 induces tumor growth and metastasis while loss of Trop2 suppresses these abilities in vivo. Trop2-driven NEPC displays a significant up-regulation of PARP1, and PARP inhibitors significantly delay tumor growth and metastatic colonization and reverse neuroendocrine features in Trop2-driven NEPC. Our findings establish Trop2 as a driver and therapeutic target for metastatic prostate cancer with neuroendocrine phenotype and suggest that high Trop2 levels could identify cancers that are sensitive to Trop2-targeting therapies and PARP1 inhibition.
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Antígenos de Neoplasias/metabolismo , Biomarcadores Tumorais/metabolismo , Neoplasias Ósseas/secundário , Carcinoma Neuroendócrino/patologia , Moléculas de Adesão Celular/metabolismo , Regulação Neoplásica da Expressão Gênica , Poli(ADP-Ribose) Polimerase-1/metabolismo , Neoplasias de Próstata Resistentes à Castração/patologia , Animais , Antígenos de Neoplasias/genética , Apoptose , Biomarcadores Tumorais/genética , Neoplasias Ósseas/tratamento farmacológico , Neoplasias Ósseas/metabolismo , Carcinoma Neuroendócrino/tratamento farmacológico , Carcinoma Neuroendócrino/metabolismo , Moléculas de Adesão Celular/genética , Movimento Celular , Proliferação de Células , Seguimentos , Humanos , Masculino , Camundongos , Camundongos Endogâmicos NOD , Camundongos SCID , Invasividade Neoplásica , Fenótipo , Poli(ADP-Ribose) Polimerase-1/antagonistas & inibidores , Poli(ADP-Ribose) Polimerase-1/genética , Inibidores de Poli(ADP-Ribose) Polimerases/farmacologia , Prognóstico , Neoplasias de Próstata Resistentes à Castração/tratamento farmacológico , Neoplasias de Próstata Resistentes à Castração/metabolismo , Taxa de Sobrevida , Células Tumorais Cultivadas , Ensaios Antitumorais Modelo de XenoenxertoRESUMO
The angiotensin II (AngII) type 1 receptor (AT1R), a member of the G protein-coupled receptor (GPCR) family, signals through G proteins and ß-arrestins, which act as adaptors to regulate AT1R internalization and mitogen-activated protein kinase (MAPK) ERK1/2 activation. ß-arrestin-dependent ERK1/2 regulation is the subject of important studies because its spatiotemporal control remains poorly understood for many GPCRs, including AT1R. To study the link between ß-arrestin-dependent trafficking and ERK1/2 signaling, we investigated three naturally occurring AT1R variants that show distinct receptor-ß-arrestin interactions: A163T, T282M, and C289W. Using bioluminescence resonance energy transfer (BRET)-based and conformational fluorescein arsenical hairpin-BRET sensors coupled with high-resolution fluorescence microscopy, we show that all AT1R variants form complexes with ß-arrestin2 at the plasma membrane and efficiently internalize into endosomes upon AngII stimulation. However, mutant receptors imposed distinct conformations in ß-arrestin2 and differentially impacted endosomal trafficking and MAPK signaling. Notably, T282M accumulated in endosomes, but its ability to form stable complexes following internalization was reduced, markedly impairing its ability to co-traffic with ß-arrestin2. We also found that despite ß-arrestin2 overexpression, T282M's and C289W's residency with ß-arrestin2 in endosomes was greatly reduced, leading to decreased ß-arrestin-dependent ERK1/2 activation, faster recycling of receptors to the plasma membrane, and impaired AngII-mediated proliferation. Our findings reveal that naturally occurring AT1R variants alter the patterns of receptor/ß-arrestin2 trafficking and suggest conformationally dependent ß-arrestin-mediated MAPK activation as well as endosomal receptor-ß-arrestin complex stabilization in the mitogenic response of AT1R.
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Endossomos/metabolismo , Sistema de Sinalização das MAP Quinases , Proteína Quinase 1 Ativada por Mitógeno/metabolismo , Proteína Quinase 3 Ativada por Mitógeno/metabolismo , Receptor Tipo 1 de Angiotensina/metabolismo , beta-Arrestinas/metabolismo , Substituição de Aminoácidos , Angiotensina II/farmacologia , Endossomos/genética , Ativação Enzimática , Células HEK293 , Humanos , Proteína Quinase 1 Ativada por Mitógeno/genética , Proteína Quinase 3 Ativada por Mitógeno/genética , Mutação de Sentido Incorreto , Receptor Tipo 1 de Angiotensina/genética , beta-Arrestinas/genéticaRESUMO
Background: The emergence of the coronavirus disease 2019 (COVID-19) pandemic has created unprecedented challenges across the globe. In addition to its debilitating impacts on health, the pandemic has also resulted in sudden changes in the quality of life. Our study aims to assess and highlight the alterations in lifestyle, health practices, and perceived anxiety in amongst the Pakistani denizens during the categorical lockdown across the country. Methods: A cross-sectional study was conducted during April 2020 through an online self-administered questionnaire using the snowball sampling technique. The online survey included a diversified set of questions ranging from the demographics, participants' sleeping routine, physical activity, hygiene habits, daily routine, and dietary habits during the quarantine period. It also assessed their anxiety through a series of questions, stretching from their own apprehension of their mental health to their assumption regarding the uncertainty of the future. SPSS v23 was used for data analysis, and chi-square test was applied. Results: A total of 384 respondents were included in the study. The mean age of the participants was 21.26 ± 4.267 years. It was observed that 203 (52.9%) individuals spent most of their time in self-isolation on social media, and 167 (43.5%) of participants claimed to be undertaking online classes or watching television. Furthermore, half of the participants noted that their sleep duration had increased 194 (50.5%), along with increased levels of perceived anxiety 242 (63%). Conclusion: The imposed nationwide lockdown due to COVID-19 has extensively affected the daily routine of the people living in Pakistan, eliciting profound changes in their sleeping patterns, dietary habits, mental health, and physical activity. Therefore, addressing the issues that arise amidst the lockdown remains pivotal.
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Malaria is a major public health problem all over the world, particularly in tropical and subtropical countries due to the development of resistance and most deadly infection is caused by Plasmodium falciparum. There is a direct need for the discovery of new drugs with unique structures and mechanism of action to treat sensitive and drug-resistant strains of various plasmodia for radical cure of this disease. Traditional compounds such as quinine and related derivatives represent a major source for the development of new drugs. This review presents recent modifications of 4-aminoquinoline and 8-aminoquinolone rings as leads to novel active molecules which are under clinical trials. The review also encompasses the other heterocyclic compounds emerged as potential antimalarial agents with promising results such as acridinediones and acridinone analogues, pyridines and quinolones as antimalarials. Miscellaneous heterocyclics such as tetroxane derivatives, indole derivatives, imidazolopiperazine derivatives, biscationic choline-based compounds and polymer-linked combined antimalarial drugs are also discussed. At last brief introduction to heterocyclics in natural products is also reviewed. Most of them have been under clinical trials and found to be promising in the treatment of drug-resistant strains of Plasmodium and others can be explored for the same purpose.
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Antimaláricos/química , Antimaláricos/farmacologia , Compostos Heterocíclicos/química , Acridinas/química , Aminoquinolinas/química , Aminoquinolinas/farmacologia , Antimaláricos/síntese química , Produtos Biológicos/química , Produtos Biológicos/farmacologia , Ensaios Clínicos como Assunto , Resistência Microbiana a Medicamentos/efeitos dos fármacos , Compostos Ferrosos/química , Compostos Ferrosos/farmacologia , Humanos , Malária/tratamento farmacológico , Metalocenos , Piridonas/química , Pirimidinas/químicaRESUMO
PURPOSE: The synthesis and evaluation of novel biodegradable poly(organophosphazenes) (3-6) namely poly[bis-(2-propoxy)]phosphazene (3) poly[bis(4-acetamidophenoxy)]phosphazene (4)poly[bis(4-formylphenoxy)]phosphazene (5) poly[bis(4-ethoxycarbonylanilino)]phosphazene (6) bearing various hydrophilic and hydrophobic side groups for their application as nonocarrier system for antimalarial drug delivery is described. METHODS: The characterization of polymers was carried out by IR, (1)H-NMR and (31)P-NMR. The molecular weights of these novel polyphosphazenes were determined using size exclusion chromatography with a Waters 515 HPLC Pump and a Waters 2414 refractive index detector. The degradation behavior was studied by 200 mg pellets of polymers in phosphate buffers pH 5.5, 6.8 and 7.4 at 37°C. The degradation process was monitored by changes of mass as function of time and surface morphology of polymer pellets. The developed combined drugs nanoparticles formulations were evaluated for antimalarial potential in P. berghei infected mice. RESULTS: These polymers exhibited hydrolytic degradability, which can afford applications to a variety of drug delivery systems. On the basis of these results, the synthesized polymers were employed as nanocarriers for targeted drug delivery of primaquine and dihydroartemisinin. The promising in vitro release of both the drugs from nanoparticles formulations provided an alternative therapeutic combination therapy regimen for the treatment of drug resistant malaria. The nanoparticles formulations tested in resistant strain of P. berghei infected mice showed 100% antimalarial activity. CONCLUSIONS: The developed nanocarrier system provides an alternative combination regimen for the treatment of resistant malaria.
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Antimaláricos/administração & dosagem , Artemisininas/administração & dosagem , Portadores de Fármacos/síntese química , Portadores de Fármacos/farmacologia , Compostos Organofosforados/síntese química , Compostos Organofosforados/farmacologia , Polímeros/síntese química , Polímeros/farmacologia , Primaquina/administração & dosagem , Animais , Antimaláricos/química , Artemisininas/química , Sistemas de Liberação de Medicamentos , Eletroquímica , Eritrócitos/efeitos dos fármacos , Humanos , Técnicas In Vitro , Malária/tratamento farmacológico , Malária/parasitologia , Camundongos , Nanopartículas , Tamanho da Partícula , Plasmodium berghei , Primaquina/química , Espectrofotometria Infravermelho , Taxa de SobrevidaRESUMO
Metal phosphides are promising catalysts for hydrogenation reactions due to their unique ability to generate active hydrogen species which are essential for desired reactions. In this work, the hydrogenation potential of nickel phosphide (Ni2P) is explored for the transfer hydrogenation of aromatic nitro compounds using hydrazine hydrate as hydrogen source. The Ni2P was supported on activated carbon (AC) to facilitate highly exposed active reaction sites. The as-synthesized Ni2P-AC catalyst showed excellent catalytic potential for the hydrogenation of nitro compounds to corresponding amines with 100% conversion efficiency and resulted in excellent yields. The reaction conditions were optimized by varying different reaction parameters, such as time, temperature, solvents, catalyst amount and hydrogen sources. The developed reaction protocol is highly selective for nitro compounds having reduction susceptible functional groups like -Cl, -Br, -CHO, etc. The structure-activity relationship of the Ni2P-AC was also examined which suggested that both acidic and basic sites present in Ni2P-AC catalyst plays crucial role in hydrogenation reaction. Besides, an in-depth insight into the reaction mechanism illustrates that the reaction proceeds via N-phenyl hydroxylamine as the reaction intermediate. In addition, decent recyclability and stability of Ni2P-AC catalyst demonstrates its highly versatile nature for potential large-scale applications. The use of highly efficient Ni2P-AC catalyst for hydrogenation reactions can lead the way towards sustainable and effective industrial organic catalysis.
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Phosphoinositides, phospholipids that are key cell-signal mediators, are present at very low levels in cellular membranes and within nuclei. Phosphatidylinositol-(3,4,5)-trisphosphate (PIP3), a phosphoinositide barely present in resting cell membranes, is produced when cells receive either growth, proliferation, or movement signals. Aberrant PIP3 levels are associated with the formation of cancers. PIP3 pools are also present in the nucleus, specifically in the nucleolus. However, questions related to the organization and function of this lipid in such membraneless intranuclear structures remain unanswered. Therefore, chemical sensors for tracking cellular PIP3 are invaluable not only for timing signal initiation in membranes but also for identifying the organization and function of membraneless nuclear PIP3 pools. Because PIP3 is present in the inner leaflet of cell membranes and in the nucleus, cell-permeable, rapid-response fluorescent sensors would be ideal. We have designed two peptide-based, water-soluble, cell-permeable, ratiometric PIP3 sensors named as MFR-K17H and DAN-NG-H12G. MFR-K17H rapidly entered into the cell cytoplasm, distinctly reporting rapid (<1 min) time scales of growth factor-stimulated PIP3 generation and depletion within cell membranes in living cells. Importantly, MFR-K17H lighted up inherently high levels of PIP3 in triple-negative breast cancer cell membranes, implying future applications in the detection of enhanced PIP3 levels in cancerous cells. On the other hand, DAN-NG-H12G targeted intranuclear PIP3 pools, revealing that within membraneless structures, PIP3 resided in a hydrophobic environment. Together, both probes form a unique orthogonally targeted combination of cell-permeable, ratiometric probes that, unlike previous cell-impermeable protein-based sensors, are easy to apply and provide an unprecedented handle into PIP3-mediated cellular processes.
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Layered double hydroxides (LDH) have significant attention in recent times due to their unique characteristic properties, including layered structure, variable compositions, tunable acidity and basicity, memory effect, and their ability to transform into various kinds of catalysts, which make them desirable for various types of catalytic applications, such as electrocatalysis, photocatalysis, and thermocatalysis. In addition, the upcycling of lignocellulose biomass and its derived compounds has emerged as a promising strategy for the synthesis of valuable products and fine chemicals. The current review focuses on recent advancements in LDH-based catalysts for biomass conversion reactions. Specifically, this review highlights the structural features and advantages of LDH and LDH-derived catalysts for biomass conversion reactions, followed by a detailed summary of the different synthesis methods and different strategies used to tailor their properties. Subsequently, LDH-based catalysts for hydrogenation, oxidation, coupling, and isomerization reactions of biomass-derived molecules are critically summarized in a very detailed manner. The review concludes with a discussion on future research directions in this field which anticipates that further exploration of LDH-based catalysts and integration of cutting-edge technologies into biomass conversion reactions hold promise for addressing future energy challenges, potentially leading to a carbon-neutral or carbon-positive future.
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BACKGROUND: Among various carboxylic acid derivatives, valeric acid or pentanoic acid is found to be widely distributed in nature. It is a straight-chain alkyl carboxylic acid containing five carbon atoms. Due to the therapeutic value of valeric acid, it is used as a versatile nucleus in the pharmaceutical field. Valeric acid derivatives are associated with a broad spectrum of biological activities, like anticonvulsant, antiplatelet, antidiabetic, and plant growth activities. AIM: It has previously been revealed that peptide derivatives of carboxylic acids are accountable for enhanced antimicrobial activity. Therefore, it was hypothesized that coupling peptides with valeric acid would increase the antimicrobial properties of the target compounds. So, the objective of the present study was to synthesize peptide derivatives of 5-bromovaleric acid and evaluate their antibacterial and antifungal activities. METHODS: 5-bromovaleric acid was synthesized by the reaction of cyclopentanone and hydrogen peroxide in the presence of copper bromide and sodium bromide. Additionally, 5-bromovaleric acid was coupled with amino acid methyl esters, dipeptides, tripeptides, and tetrapeptides in the presence of dicyclohexylcarbodimide (DCC) and N-methylmorpholine (NMM) as a base under continuous stirring for 36 hours to produce its peptide derivatives. RESULTS: The results obtained showed that 5-bromovaleric acid possesses more potent antibacterial activity than N-terminal 5-bromovaleric acid conjugates of selected di-, tri, and tetra peptide Cterminal methyl esters against ciprofloxacin as a standard. The selected dipeptide and tripeptide Nterminal 5-bromovaleric acid-conjugated C-terminal methyl ester derivatives were more active than the selected tetrapeptide methyl ester analogue. Using fluconazole as a reference, the antifungal efficacy of 5-bromovaleric acid against C. albicans and A. niger declined as it was combined with C-terminal methyl esters of selected dipeptides, tripeptides, and tetrapeptides. CONCLUSION: The novel selected peptide derivatives had less antibacterial and antifungal action than the parent 5-bromovaleric acid. Antibacterial and antifungal investigations showed that 5- bromopentanoic acid peptide derivatives might impair antimicrobial efficacy. Further, attaching 5- bromopentanoic acid to di, tri, and tetra peptides did not boost their antibacterial potential.
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Gastrointestinal stromal tumors (GISTs) are rare tumors of the gastrointestinal (GI) tract. Intermittent GI bleeding is the most common manifestation. Massive GI bleeding leading to syncopal episodes and hemorrhagic shock is a rare presentation of these tumors. Herein, we describe a case of a jejunal GIST presenting as massive bleeding.