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1.
Bioorg Med Chem Lett ; 25(1): 117-21, 2015 Jan 01.
Artículo en Inglés | MEDLINE | ID: mdl-25466200

RESUMEN

Two substituted biaryl analogues of colchicine and combretastatin A4, readily available through a one-step, protecting group free Suzuki-Miyaura reaction were discovered to exhibit anticancer activity while simultaneously being of low cytotoxicity to noncancerous cell lines. The compounds were shown to initiate apoptosis selectively via a mechanism involving inhibition of tubulin polymerization.


Asunto(s)
Antimitóticos/química , Antineoplásicos Fitogénicos/química , Colchicina/análogos & derivados , Estilbenos/química , Línea Celular Tumoral , Relación Dosis-Respuesta a Droga , Humanos , Relación Estructura-Actividad
2.
Proc Natl Acad Sci U S A ; 109(15): 5681-6, 2012 Apr 10.
Artículo en Inglés | MEDLINE | ID: mdl-22451903

RESUMEN

In mycobacteria, polyketide synthases and nonribosomal peptide synthetases (NRPSs) produce complex lipidic metabolites by using a thio-template mechanism of catalysis. In this study, we demonstrate that off-loading reductase (R) domain of mycobacterial NRPSs performs two consecutive [2 + 2]e(-) reductions to release thioester-bound lipopeptides as corresponding alcohols, using a nonprocessive mechanism of catalysis. The first crystal structure of an R domain from Mycobacterium tuberculosis NRPS provides strong support to this mechanistic model and suggests that the displacement of intermediate would be required for cofactor recycling. We show that 4e(-) reductases produce alcohols through a committed aldehyde intermediate, and the reduction of this intermediate is at least 10 times more efficient than the thioester-substrate. Structural and biochemical studies also provide evidence for the conformational changes associated with the reductive cycle. Further, we show that the large substrate-binding pocket with a hydrophobic platform accounts for the remarkable substrate promiscuity of these domains. Our studies present an elegant example of the recruitment of a canonical short-chain dehydrogenase/reductase family member as an off-loading domain in the context of assembly-line enzymology.


Asunto(s)
Electrones , Mycobacterium tuberculosis/enzimología , Péptido Sintasas/química , Péptido Sintasas/metabolismo , Alcoholes/metabolismo , Sitios de Unión , Cristalografía por Rayos X , Glicopéptidos/química , Glicopéptidos/metabolismo , Lipopéptidos/química , Lipopéptidos/metabolismo , Modelos Moleculares , NADP , Oxidación-Reducción , Oxidorreductasas/química , Oxidorreductasas/metabolismo , Estructura Terciaria de Proteína , Especificidad por Sustrato
3.
Antimicrob Agents Chemother ; 58(9): 5435-47, 2014 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-24982082

RESUMEN

Toward the discovery of useful therapeutic molecules, we report the design and synthesis of a focused library of new ultrashort N-terminally modified dipeptidomimetics, with or without modifications in the spermine backbone leading to linear (series 1) or branched (series 2) tryptophans, as antimicrobial agents. Eight peptidomimetics in the library showed good antibacterial activity (MICs of 1.77 to 14.2 µg/ml) against methicillin-resistant Staphylococcus aureus (MRSA) and methicillin-resistant Staphylococcus epidermidis bacterial strains. Tryptophan fluorescence measurements on artificial bacterial or mammalian mimic membranes and assessment of the MRSA potential depolarization ability of the designed compounds revealed membrane interactions dependent on tryptophan positioning and N-terminal tagging. Among active peptidomimetics, compounds 1c and 1d were found to be nonhemolytic, displaying rapid bactericidal activity (at 4× MIC) against exponentially growing MRSA. Further, scanning electron microscopy of peptidomimetic 1c- and 1d-treated MRSA showed morphological changes with damage to cell walls, defining a membrane-active mode of action. Moreover, peptidomimetics 1c and 1d did not induce significant drug resistance in MRSA even after 17 passages. We also investigated the activity of these molecules against MRSA biofilms. At sub-MIC levels (∼2 to 4 µg/ml), both peptidomimetics inhibited biofilm formation. At concentrations higher than the MIC (35 to 140 µg/ml), peptidomimetics 1c and 1d significantly reduced the metabolic activity and biomass of mature (24-h) MRSA biofilms. These results were corroborated by confocal laser scanning microscopy (live/dead assay). The in vitro protease stability and lower cytotoxicity of peptidomimetics against peripheral blood mononuclear cells (PBMCs) support them being novel staphylocidal peptidomimetics. In conclusion, this study provides two peptidomimetics as potential leads for treatment of staphylococcal infections under planktonic and sessile conditions.


Asunto(s)
Staphylococcus aureus Resistente a Meticilina/efectos de los fármacos , Plancton/efectos de los fármacos , Espermina/química , Espermina/farmacología , Infecciones Estafilocócicas/tratamiento farmacológico , Antibacterianos/farmacología , Biopelículas/efectos de los fármacos , Humanos , Leucocitos Mononucleares/efectos de los fármacos , Leucocitos Mononucleares/microbiología , Pruebas de Sensibilidad Microbiana/métodos , Staphylococcus epidermidis/efectos de los fármacos
4.
Infect Dis Ther ; 13(4): 685-697, 2024 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-38483775

RESUMEN

INTRODUCTION: Influenza is a common, seasonal infectious disease with broad medical, economic, and social consequences. Real-world evidence on the effect of influenza treatment on household transmission and healthcare resource utilization is limited in outpatient settings in the USA. This study examined the real-world effectiveness of baloxavir vs oseltamivir in reducing influenza household transmission and healthcare resource utilization. METHODS: This prospective electronic survey on patient-reported outcomes was conducted between October 2022 and May 2023 via CVS Pharmacy in the USA. Adult participants (≥ 18 years old) were eligible if they filled a prescription for baloxavir or oseltamivir at a CVS Pharmacy within 2 days of influenza symptom onset. Participant demographics, household transmission, and all-cause healthcare resource utilization were collected. Transmission and utilization outcomes were assessed using χ2 and Fisher exact tests. RESULTS: Of 87,871 unique patients contacted, 1346 (1.5%) consented. Of 374 eligible patients, 286 (90 baloxavir- and 196 oseltamivir-treated patients) completed the survey and were included in the analysis. Mean age of participants was 45.4 years, 65.6% were female, and 86.7% were White. Lower household transmission was observed with baloxavir compared with oseltamivir therapy (17.8% vs 26.5%; relative risk = 0.67; 95% CI 0.41-1.11). Healthcare resource utilization, particularly emergency department visits (0.0% vs 4.6%), was also numerically lower in the baloxavir-treated group; no hospitalizations were reported in either cohort. CONCLUSIONS: The findings from this real-world study suggest that antiviral treatment of influenza with baloxavir may decrease household transmission and reduce healthcare resource utilization compared with oseltamivir.

5.
Infect Control Hosp Epidemiol ; : 1-3, 2024 Mar 20.
Artículo en Inglés | MEDLINE | ID: mdl-38505952

RESUMEN

An infection prevention bundle that consisted of the development of a response team, public-academic partnership, daily assessment, regular testing, isolation, and environmental controls was implemented in 26 skilled nursing facilities in Detroit, Michigan (March 2020-April 2021). This intervention was associated with sustained control of severe acute respiratory coronavirus virus 2 infection among residents and staff.

6.
IDCases ; 33: e01886, 2023.
Artículo en Inglés | MEDLINE | ID: mdl-37674901

RESUMEN

Background: Tuberculosis (TB) is the second leading cause of death due to an infectious disease worldwide (World Health Organization, 2022 [1]). The first line treatment of TB involves the concurrent use of four drugs: rifampin, isoniazid, pyrazinamide, and ethambutol (RIPE). Given the rising threat of multidrug resistant TB, it is crucial to understand how TB can be treated when first line treatment is not an option. Case presentation: We report a rare case of multi-drug hypersensitivity to RIPE therapy in an immunocompetent patient with an unusual presentation of CNS tuberculoma. The patient presented to an outside hospital four months prior with weakness, numbness, imbalance, and speech difficulties. A CT of the head revealed a mass in the left parietal lobe that demonstrated chronic necrotizing granulomatous inflammation with positive cultures for M. tuberculosis. The patient was started on a regimen of rifampin 600 mg daily, isoniazid 300 mg daily, pyrazinamide 2000 mg daily, ethambutol 1200 mg daily, and pyridoxine 50 mg daily. However, the patient developed drug hypersensitivity reactions to both rifampin and ethambutol with subsequent failed desensitization to rifabutin. She was ultimately discharged from the hospital on a regimen of isoniazid, pyridoxine, pyrazinamide, and moxifloxacin with plans for outpatient follow-up. Conclusions: This case highlights a rare clinical presentation of multiple drug hypersensitivity in the setting of a CNS tuberculoma and the importance of identifying the offending agents early in the course of treatment and adjusting the drug regimen accordingly. Desensitization should be attempted, but if ineffective, then alternative drug regimens should be formulated on a case-by-case basis.

7.
J Trace Elem Med Biol ; 79: 127245, 2023 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-37406475

RESUMEN

Many transition metal complexes have been explored for their therapeutic properties after the discovery of cisplatin. Schiff bases have an efficient complexation tendency with the transition metals and several medicinal properties have been reported. However, fewer studies have reported the medicinal utility of vanadium and its Schiff base complexes. This paper provides a comprehensive overview of vanadium complexes with Schiff bases along with their mechanistic insight. Vanadium complexes in + 4 and + 5 oxidation states have exhibited well-defined geometry and found to be thermodynamically stable. The studies have reported the G0/G1 phase cell cycle arrest and decreased delta psi m, inducing mitochondrial membrane depolarization in cancer cell lines along with the alterations in the metabolism of the cancer cells upon dosing with the vanadium complexes. Cancer cell invasion and growth are also found to be markedly reduced by peroxo complexes of vanadium. The studies included in the review paper have been taken from leading indexing databases and focus was laid on recent reports in literature. The biological potential of vanadium complexes of Schiff bases opens new horizons for future interdisciplinary studies and investigation focussed on understanding the biochemistry of these complexes, along with designing new complexes which have better bioavailability, solubility and low or non-toxicity.


Asunto(s)
Complejos de Coordinación , Vanadio , Vanadio/farmacología , Bases de Schiff/farmacología , Bases de Schiff/química , Complejos de Coordinación/farmacología , Complejos de Coordinación/química , Cisplatino , Oxidación-Reducción
8.
Hum Vaccin Immunother ; 19(1): 2166321, 2023 12 31.
Artículo en Inglés | MEDLINE | ID: mdl-36691997

RESUMEN

Vaccine hesitancy during the COVID-19 pandemic continues to be an issue in terms of global efforts to decrease transmission rates. Despite high demand for the vaccines in Nepal, the country still contends with challenges related to vaccine accessibility, equitable vaccine distribution, and vaccine hesitancy. Study objectives were to identify: 1) up-take and intention for use of COVID-19 vaccines, 2) factors associated with vaccine up-take, and 3) trusted communication strategies about COVID-19 and the vaccines. A quantitative survey was implemented in August and September 2021 through an initiative at the Nepali Ministry of Health and Population Department of Health Services, Family Welfare Division. Data were collected from 865 respondents in three provinces (Bagmati, Lumbini, and Province 1). Ordinal multivariate logistic regression was utilized to determine relationships between vaccination status and associated factors. Overall, 62% (537) respondents were fully vaccinated and 18% (159) were partially vaccinated. Those respondents with higher education (p < .001) and higher household income (p < .001) were more likely vaccinated. There were also significant differences in vaccine up-take across the three provinces (p < .001). Respondents who were vaccinated were significantly more likely to perceive vaccines as efficacious in terms of preventing COVID-19 (p = .004) and preventing serious outcomes (p = .010). Among both vaccinated and unvaccinated individuals, there was a high level of trust in information about COVID-19 vaccines provided through local health-care workers [e.g. nurses and physicians]. These results are consistent with other findings within the South Asia region. Targeted advocacy and outreach efforts are needed to support ongoing COVID-19 vaccination campaigns throughout Nepal.


Asunto(s)
Vacunas contra la COVID-19 , COVID-19 , Humanos , Nepal/epidemiología , Pandemias , COVID-19/epidemiología , COVID-19/prevención & control , Vacunación
9.
Org Biomol Chem ; 10(41): 8326-35, 2012 Oct 03.
Artículo en Inglés | MEDLINE | ID: mdl-22986997

RESUMEN

Towards therapeutically viable mimics of host defense cationic peptides (HDCPs) here we report the design and synthesis of a small library, based on a novel hydrophobic-dipeptide-spermidine template. Lipidated sequences 11, 14, 15, 16, 18 and 19 exhibited potent activity against susceptible as well as drug resistant Gram-positive and Gram-negative bacterial strains. Structure-activity relationships of the template revealed a hydrophobicity window of 50-70% with minimum +2 charges to be crucial for activity and cell selectivity. Active sequences 14, 15 and 16 exhibited different modes of action based on dipeptide composition as revealed by studies on model membranes, intact bacterial cells and DNA. Further, severe damage to surface morphology of methicillin resistant S. aureus caused by 14, 15 and 16 at 10 × MIC was observed. The present study provides us two active sequences (14 and 16) with a membrane perturbing mode of action, cell selectivity to hRBCs and keratinocytes along with potent activity against clinically relevant pathogen MRSA. The designed template thus may prove to be a suitable probe to optimize sequences for better selectivity and potential to combat a wide range of drug resistant strains in further research.


Asunto(s)
Antibacterianos/síntesis química , Antibacterianos/farmacología , Bacterias/efectos de los fármacos , Dipéptidos/química , Diseño de Fármacos , Ácido Linoleico/química , Espermidina/química , Antibacterianos/química , Línea Celular , Supervivencia Celular/efectos de los fármacos , Cromatografía Líquida de Alta Presión , Humanos , Interacciones Hidrofóbicas e Hidrofílicas , Pruebas de Sensibilidad Microbiana , Microscopía Electrónica de Rastreo , Estructura Molecular
10.
Arch Pharm (Weinheim) ; 345(11): 896-901, 2012 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-22945019

RESUMEN

A library of unsymmetrical cyclohexane-1,2-diamine derivatives were synthesized and evaluated for their activity against Mycobacterium tuberculosis H37Rv in vitro. Out of the 46 compounds synthesized, eight compounds (11h, 13a, 13e, 13f, 14a, 14c, 14d, and 15d) were found to be active at or below 6.25 µM concentration, with negligible toxicity to human red blood cells at a concentration much higher than the MIC(99) . Compound 13a was the best active compound showing inhibition at 3.125-6.25 µM, and was found to be non-hemolytic up to 500 µg/mL concentration.


Asunto(s)
Antituberculosos/farmacología , Ciclohexanos/farmacología , Diaminas/farmacología , Mycobacterium tuberculosis/efectos de los fármacos , Antituberculosos/síntesis química , Antituberculosos/química , Ciclohexanos/síntesis química , Ciclohexanos/química , Diaminas/síntesis química , Diaminas/química , Relación Dosis-Respuesta a Droga , Hemólisis/efectos de los fármacos , Humanos , Pruebas de Sensibilidad Microbiana , Relación Estructura-Actividad , Pruebas de Toxicidad/métodos
11.
ACS Infect Dis ; 8(12): 2480-2493, 2022 12 09.
Artículo en Inglés | MEDLINE | ID: mdl-36440863

RESUMEN

Methicillin-resistant Staphylococcus aureus (MRSA), a biofilm-forming recalcitrant pathogen with a multidrug-resistant profile, poses a pandemic threat to human health and is the leading cause of severe infections in both healthcare and community settings. In this study, toward designing novel α-MSH-based peptides with enhanced activity and stability against MRSA, particularly its stationary phase and biofilm, we explored a design approach to augment the hydrophobicity of an 8-mer C-terminal α-MSH(6-13)-based peptide Ana-5 through the incorporation of a bulky unnatural amino acid. The designed Ana-peptides overcame the limitation of diminished activity in biological media and exhibited enhanced antistaphylococcal activity and cell selectivity. With membrane rupture as the primary mode of action, the peptides exhibited inhibitory potential against S. aureus biofilms. Importantly, the peptides did not exhibit any adverse effects in the in vivo toxicity studies and were also able to significantly alleviate bacterial infection in a systemic infection mice model study. Additionally, the peptides retained their activity in the presence of serum and displayed a low propensity toward resistance development in MRSA cells. Moreover, the observed synergistic potential of Ana-10 with conventional antibiotics could be vital in resurrecting discarded antibiotics. Thus, this study provides us with an exciting lead, Ana-10, for further development against biofilm-based chronic S. aureus infections.


Asunto(s)
Staphylococcus aureus Resistente a Meticilina , beta-Lactamas , Humanos , Animales , Ratones , alfa-MSH , Staphylococcus aureus
12.
Antibiotics (Basel) ; 11(5)2022 May 11.
Artículo en Inglés | MEDLINE | ID: mdl-35625286

RESUMEN

Antimicrobial stewardship programs (ASPs) are effective means to optimize prescribing practices. They are under-utilized in the Middle East where many challenges exist for ASP implementation. We assessed the effectiveness of infectious disease physician-driven post-prescription review and feedback as an ASP in Lebanon. This prospective cohort study was conducted over an 18-month period in the medical, surgical, and intensive care units of a tertiary care hospital. It consisted of three phases: the baseline, intervention, and follow-up. There was a washout period of two months between each phase. Patients aged ≥16 years receiving 48 h of antibiotics were included. During the intervention phase, the AMS team reviewed antimicrobial use within 72 h post-prescription and gave alternate recommendations based on the guidelines for use. The acceptance of the recommendations was measured at 72 h. The primary outcome of the study was days of therapy per 1000 study patient days. A total of 328 patients were recruited in the baseline phase (August−October 2020), 467 patients in the intervention phase (January−June 2021), and 301 patients in the post-intervention phase (September−December 2021). The total days of therapy decreased from 11.46 during the baseline phase to 8.64 during the intervention phase (p < 0.001). Intervention acceptance occurred 88.5% of the time. The infectious disease physician-driven implementation of an ASP was successful in reducing antibiotic utilization in an acute care setting in Lebanon.

13.
Open Forum Infect Dis ; 9(1): ofab619, 2022 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-35024376

RESUMEN

BACKGROUND: Corticosteroids use in severe coronavirus disease 2019 (COVID-19) improves survival; however, the optimal dose is not established. We aim to evaluate clinical outcomes in patients with severe COVID-19 receiving high-dose corticosteroids (HDC) versus low-dose corticosteroids (LDC). METHODS: This was a quasi-experimental study conducted at a large, quaternary care center in Michigan. A corticosteroid dose change was implemented in the standardized institutional treatment protocol on November 17, 2020. All patients admitted with severe COVID-19 that received corticosteroids were included. Consecutive patients in the HDC group (September 1 to November 15, 2020) were compared to the LDC group (November 30, 2020 to January 20, 2021). High-dose corticosteroids was defined as 80 mg of methylprednisolone daily in 2 divided doses, and LDC was defined as 32-40 mg of methylprednisolone daily in 2 divided doses. The primary outcome was all-cause 28-day mortality. Secondary outcomes included progression to mechanical ventilation, hospital length of stay (LOS), discharge on supplemental oxygen, and corticosteroid-associated adverse events. RESULTS: Four-hundred seventy patients were included: 218 (46%) and 252 (54%) in the HDC and LDC groups, respectively. No difference was observed in 28-day mortality (14.5% vs 13.5%, P = .712). This finding remained intact when controlling for additional variables (odds ratio, 0.947; confidence interval, 0.515-1.742; P = .861). Median hospital LOS was 6 and 5 days in the HDC and LDC groups, respectively (P < .001). No differences were noted in any of the other secondary outcomes. CONCLUSIONS: Low-dose methylprednisolone had comparable outcomes including mortality to high-dose methylprednisolone for the treatment of severe COVID-19.

14.
Biochim Biophys Acta ; 1798(10): 1864-75, 2010 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-20599694

RESUMEN

Cationic antimicrobial peptides (CAMPs) are novel candidates for drug development. Here we describe design of six short and potent CAMPs (SA-1 to SA-6) based on a minimalist template of 12 residues H+HHG+HH+HH+NH2 (where H: hydrophobic amino acid and +: charged hydrophilic amino acid). Designed peptides exhibit good antibacterial activity in micro molar concentration range (1-32 mug/ml) and rapid clearance of Gram-positive and Gram-negative bacterial strains at concentrations higher than MIC. For elucidating mode of action of designed peptides various biophysical studies including CD and Trp fluorescence were performed using model membranes. Further based on activity, selectivity and membrane bound structure; modes of action of Trp rich peptide SA-3 and template based peptide SA-4 were compared. Calcein dye leakage and transmission electron microscopic studies with model membranes exhibited selective membrane active mode of action for peptide SA-3 and SA-4. Extending our work from model membranes to intact E. coli ATCC 11775 in scanning electron micrographs we could visualize different patterns of surface perturbation caused by peptide SA-3 and SA-4. Further at low concentration rapid translocation of FITC-tagged peptide SA-3 into the cytoplasm of E. coli cells without concomitant membrane perturbation indicates involvement of intracellular targeting mechanism as an alternate mode of action as was also evidenced in DNA retardation assay. For peptide SA-4 concentration dependent translocation into the bacterial cytoplasm along with membrane perturbation was observed. Establishment of a non specific membrane lytic mode of action of these peptides makes them suitable candidates for drug development.


Asunto(s)
Péptidos Catiónicos Antimicrobianos/metabolismo , Escherichia coli/metabolismo , Membrana Dobles de Lípidos/metabolismo , Péptidos/metabolismo , Secuencia de Aminoácidos , Animales , Antiinfecciosos/química , Antiinfecciosos/metabolismo , Antiinfecciosos/farmacología , Péptidos Catiónicos Antimicrobianos/química , Péptidos Catiónicos Antimicrobianos/farmacología , Bovinos , Dicroismo Circular , Escherichia coli/efectos de los fármacos , Escherichia coli/ultraestructura , Bacterias Gramnegativas/efectos de los fármacos , Bacterias Gramnegativas/metabolismo , Bacterias Grampositivas/efectos de los fármacos , Bacterias Grampositivas/metabolismo , Membrana Dobles de Lípidos/química , Pruebas de Sensibilidad Microbiana , Viabilidad Microbiana/efectos de los fármacos , Microscopía Confocal , Microscopía Electrónica de Transmisión , Péptidos/química , Péptidos/farmacología , Unión Proteica
15.
Infect Dis Clin North Am ; 35(4): 953-968, 2021 12.
Artículo en Inglés | MEDLINE | ID: mdl-34752227

RESUMEN

Vancomycin-resistant enterococcus (VRE) is a pathogen of growing concern due to increasing development of antibiotic resistance, increasing length of hospitalizations and excess mortality. The utility of some infection control practices are debatable, as newer developments in infection prevention strategies continued to be discovered. This article summarizes the significance of VRE and VRE transmission, along with highlighting key changes in infection control practices within the past 5 years.


Asunto(s)
Infección Hospitalaria/prevención & control , Enterococcus/efectos de los fármacos , Infecciones por Bacterias Grampositivas/prevención & control , Enterococos Resistentes a la Vancomicina , Vancomicina/farmacología , Programas de Optimización del Uso de los Antimicrobianos , Niño , Resistencia a Múltiples Medicamentos , Humanos , Control de Infecciones/organización & administración , Pediatría , Vancomicina/uso terapéutico
16.
Curr Comput Aided Drug Des ; 17(1): 107-122, 2021.
Artículo en Inglés | MEDLINE | ID: mdl-31556860

RESUMEN

BACKGROUND: Mixed ligand-metal complexes are efficient chelating agents because of their flexible donor ability. Mixed ligand complexes containing hetero atoms sulphur, nitrogen and oxygen have been probed for their biological significance. METHODS: Nine mixed ligand-metal complexes of 2-(butan-2-ylidene) hydrazinecarbothioamide (2- butanone thiosemicarbazone) with pyridine, bipyridine and 2-picoline as co-ligands were synthesized with Cu, Co and Zn salts. The complexes were tested against MDA-MB231 (MDA) and A549 cell lines. Antibacterial activity was tested against Staphylococcus aureus and Escherichia coli. The drug character of the complexes was evaluated on parameters viz. physicochemical properties, bioactivity scores, toxicity assessment and Absorption, Distribution, Metabolism, Excretion and Toxicity (ADMET) profile using various automated softwares. Molecular docking was performed against Ribonucleotide Reductase (RR) and topoisomerase II (topo II). RESULTS: The mixed ligand-metal complexes were synthesized by condensation reaction for 4-5 h. The characterization was done by elemental analysis, 1H-NMR, FT-IR, molar conductance and UV spectroscopic techniques. Molecular docking results showed that [Cu(C5H11N3S)(py)2(CH3COO)2], [Zn(C5H11N3S)(bpy)(SO4)] and [Zn(C5H11N3S)(2-pic)2(SO4)] displayed the lowest binding energies with respect to RR. Against topo II [Cu(C5H11N3S)(py)2(CH3COO)2], [Cu(C5H11N3S)(bpy)(CH3COO)2] and [Zn(C5H11N3S)(2-pic)2(SO4)] had the lowest energies. The druglikness assessment was done using Leadlikeness and Lipinski's rules. Not more than two violations were obtained in case of each filtering rule showing drug-like character of the mixed ligand complexes. Some of the complexes exhibited positive bioactivity scores and almost all the complexes were predicted to be safe with no hazardous effects as predicted by the toxicity assessment. Ames test predicted the non-mutagenic nature of the complexes. CONCLUSION: In vitro activity evaluation showed that [Zn(C5H11N3S)(py)2(SO4)], [Co(C5H11N3S(bpy) (Cl)2] and [Cu(C5H11N3S)(2-pic)2(CH3COO)2] were active against MDA. Against A549 [Co(C5H11N3S)(py)2(Cl)2], [Cu(C5H11N3S)(py)2(CH3COO)2] and [Co(C5H11N3S(bpy)(Cl)2] were active. Antibacterial evaluation showed that [Co(C5H11N3S)(bpy)(Cl)2], [Zn(C5H11N3S)(2-pic)2(SO4)] and [Cu(C5H11N3S)(2-pic)2(CH3COO)2] were active against S. aureus. Against E. coli, [Zn(C5H11N3S)(2- pic)2(SO4)] showed activity at 18-20 mg dose range.


Asunto(s)
Antibacterianos/farmacología , Antineoplásicos/farmacología , Hidrazinas/farmacología , Simulación del Acoplamiento Molecular , Tioamidas/farmacología , Células A549 , Antibacterianos/síntesis química , Antibacterianos/química , Antineoplásicos/síntesis química , Antineoplásicos/química , Línea Celular Tumoral , Simulación por Computador , Complejos de Coordinación/síntesis química , Complejos de Coordinación/química , Complejos de Coordinación/farmacología , Relación Dosis-Respuesta a Droga , Diseño de Fármacos , Humanos , Hidrazinas/síntesis química , Hidrazinas/química , Ligandos , Pruebas de Sensibilidad Microbiana , Tioamidas/síntesis química , Tioamidas/química
17.
Bioorg Med Chem Lett ; 20(3): 893-5, 2010 Feb 01.
Artículo en Inglés | MEDLINE | ID: mdl-20047831

RESUMEN

A series of benzyl-[3-(benzylamino-methyl)-cyclohexylmethyl]-amine derivatives with different substitution pattern on the aromatic ring have been prepared and evaluated for their antibacterial activity against Gram-positive and Gram-negative bacterial strains. Most of the compounds exhibit potent activity against Pseudomonas aeruginosa and Staphylococcus epidermidis while compounds 6l and 6m showed antibacterial activity against all the four bacterial strains with MIC values ranging from 0.002 to 0.016 microg/mL and no hemolytic activity up to 512 microg/mL in mammalian erythrocytes was observed.


Asunto(s)
Antibacterianos/síntesis química , Antibacterianos/farmacología , Farmacorresistencia Bacteriana Múltiple/fisiología , Bencilaminas/síntesis química , Bencilaminas/farmacología , Ciclohexanos/síntesis química , Ciclohexanos/farmacología , Farmacorresistencia Bacteriana Múltiple/efectos de los fármacos , Bacterias Gramnegativas/efectos de los fármacos , Bacterias Gramnegativas/crecimiento & desarrollo , Bacterias Grampositivas/efectos de los fármacos , Bacterias Grampositivas/crecimiento & desarrollo , Humanos , Pruebas de Sensibilidad Microbiana/métodos
18.
ACS Omega ; 5(7): 3258-3270, 2020 Feb 25.
Artículo en Inglés | MEDLINE | ID: mdl-32118141

RESUMEN

Antimicrobial peptides (AMPs), an essential component of innate immunity, are very important resources for human therapeutics to counter the current threat of drug resistance. We have previously established that one such AMP, α-melanocyte stimulating hormone (α-MSH), an endogenous neuropeptide, and its derivatives have potent antimicrobial activity against Staphylococcus aureus, including methicillin-resistant S. aureus (MRSA). However, the immense potential of α-MSH for therapeutic development against staphylococcal infections is marred by its reduced efficacy in the presence of standard microbiological culture medium. To overcome this issue, in this study, we designed a series of five novel analogues of the C-terminal fragment of α-MSH, i.e., α-MSH(6-13), by replacing uncharged and less hydrophobic residues with tryptophan and arginine to increase the hydrophobicity and cationic charge of the peptide, respectively. While all of the peptides showed a preferential interaction with negatively charged phospholipid vesicles, the most hydrophobic and cationic peptide, i.e., Ana-5, exhibited the highest activity against S. aureus cells while maintaining cell selectivity. Moreover, Ana-5 could retain its activity even in complex media like the Mueller Hinton broth and displayed rapid bactericidal activity in the presence of serum. Ana-5 also caused rapid bacterial membrane depolarization, permeabilization, and cell lysis and was able to bind to polyanionic plasmid DNA suggesting a possible dual mode of action of the peptide. Importantly, Ana-5 was able to eradicate intracellular S. aureus in fibroblast cells similar to conventional antibiotics. Collectively, in the present study, we obtained a potent α-MSH-based analogue with excellent staphylocidal potency in microbial growth medium and ex vivo efficacy, which may translate into therapeutic application.

19.
Chemosphere ; 257: 127277, 2020 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-32702805

RESUMEN

This work reports the fabrication of SiO2@TW nanocomposites and their application for Pb2+ and Cd2+ ions sequestration from simulated water. Residual tea waste has also been used for metal ions sequestration to compare the potential of SiO2@TW nanocomposites. The SEM, TEM, BET, FTIR and EDX techniques were employed for the characterization of SiO2@TW nanocomposites and residual tea waste. Particle sizes of SiO2@TW nanocomposites was in the range of 6.8-12 nm. The experiments were carried out in batch mode to explore the effect of various operating parameters on the sequestration of Pb2+ and Cd2+ ions from water. The experimental data was subjected to various thermodynamic, kinetic and isothermic models. According to Langmuir model, the maximum adsorption efficiency of the SiO2@TW nanocomposites was 153 mg/g for Pb2+ and 222 mg/g for Cd2+ but maximum adsorption efficiency of residual tea waste for Pb2+ was 125 mg/g and for Cd2+ was 142.9 mg/g. This study suggested that due to the presence of active sites SiO2@TW nanocomposites has greater potential for metal sequestration than residual tea waste.


Asunto(s)
Cadmio/análisis , Plomo/análisis , Nanocompuestos/química , Eliminación de Residuos Líquidos/métodos , Contaminantes Químicos del Agua/análisis , Adsorción , Iones , Cinética , Dióxido de Silicio , , Termodinámica , Aguas Residuales/química , Purificación del Agua/métodos
20.
Artículo en Inglés | MEDLINE | ID: mdl-31958038

RESUMEN

The article has been withdrawn at the request of the authors of the journal Combinatorial Chemistry & High Throughput Screening. Bentham Science apologizes to the readers of the journal for any inconvenience this may have caused. The Bentham Editorial Policy on Article Withdrawal can be found at https://benthamscience.com/editorial-policies-main.php BENTHAM SCIENCE DISCLAIMER: It is a condition of publication that manuscripts submitted to this journal have not been published and will not be simultaneously submitted or published elsewhere. Furthermore, any data, illustration, structure or table that has been published elsewhere must be reported, and copyright permission for reproduction must be obtained. Plagiarism is strictly forbidden, and by submitting the article for publication the authors agree that the publishers have the legal right to take appropriate action against the authors, if plagiarism or fabricated information is discovered. By submitting a manuscript the authors agree that the copyright of their article is transferred to the publishers if and when the article is accepted for publication.

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