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1.
J Tradit Complement Med ; 14(2): 162-172, 2024 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-38481548

RESUMO

Background and aim: Phytoformulation therapy is a pioneering strategy for the treatment of metabolic disorders and related diseases. The aim of the present study was to investigate the protective effect of a phytoformulation consisting of hydroxycitric acid and capsaicin against obesity-related cardiomyopathy. Experimental procedure: Sprague-Dawley rats were fed HFD for 21 weeks, and phytoformulation (100 mg/kg body weight) was administered orally for 45 days starting at week 16. Results and conclusion: We found that HFD supplementation resulted in significant hyperglycemia and caused an increase in cardiac lipid deposition, inflammation and apoptosis in the heart. Phytoformulation therapy not only significantly decreased blood levels of glucose, cholesterol, triglycerides, free fatty acids, and inflammatory cytokines in obese rats, but also protected cardiac tissue, as shown by histological analysis. Conversely, phytoformulation therapy decreased mRNA levels for sterol regulatory element-binding factor 1, fatty acid synthase, acetyl-CoA carboxylase, and fatty acid binding protein 1 genes involved in fatty acid synthesis and absorption in obese rats. It increased the levels of lysosomal acid lipase, hormone-sensitive lipase, and lipoprotein lipase genes involved in fatty acid degradation in the heart. In addition, the phytoformulation improved cardiac inflammation and apoptosis by downregulating the genes nuclear factor kappa-light-chain enhancer of activated B cells (NF-kB), tumour necrosis factor α, interleukin-6, toll-like receptor-4 (TLR-4), BCL2-associated X and caspase-3. In conclusion, our results show that the phytoformulation improved insulin sensitivity and attenuated myocardial lipid accumulation, inflammation, and apoptosis in the heart of HFD-induced obese rats by regulating fatty acid metabolism genes and downregulating NF-kB/TLR-4/caspase-3.

2.
Int J Obes (Lond) ; 48(2): 147-165, 2024 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-37963998

RESUMO

BACKGROUND: Obesity is a complex multifactorial disease in which the accumulation of excess body fat has adverse health effects, as it can increase the risk of several problems, including infertility, in both men and women. Obesity and infertility have risen together in recent years. Against this background, the present review aims to highlight the impact of obesity on infertility and the underlying pathophysiology of obesity-related infertility (ORI) in men and women, and to provide readers with knowledge of current trends in the effective development of phytotherapeutics for its treatment. METHODS: We thoroughly searched in PubMed, MEDLINE, Scopus, EMBASE, and Google Scholar to find all relevant papers on ORI and the therapeutic effects of phytotherapeutics on ORI in men and women. RESULTS: The extensive search of the available literature revealed that obesity affects reproductive function through several complex mechanisms such as hyperlipidaemia, hyperinsulinaemia, hyperandrogenism, increased body mass index, disruption of the hormonal milieu, systemic inflammation, oxidative stress, alterations in epigenetics and dysbiosis. On the other hand, several studies reported that phytotherapeutics has a broad therapeutic spectrum of action by improving sex hormone homeostasis, ovarian dysfunction, menstrual cycle and inhibiting ovarian hyperplasia, as well as down-regulating ovarian apoptosis, inflammation and oxidative stress, and controlling metabolic dysfunction in obese women. Male infertility is also addressed by phytotherapeutics by suppressing lipogenesis, increasing testosterone, 3ß-HSD and 17ß-HSD levels, improving sperm parameters and attenuating testicular dyslipidaemia, oxidative stress, inflammation and germ cell apoptosis. CONCLUSIONS: In the present review, we discussed the effects of obesity on reproductive dysfunction in men and women and the underlying pathophysiology of ORI. In addition, the therapeutic effect of phytotherapeutics against ORI was highlighted.


Assuntos
Infertilidade Masculina , Sêmen , Masculino , Humanos , Feminino , Sêmen/metabolismo , Obesidade/complicações , Obesidade/tratamento farmacológico , Obesidade/metabolismo , Infertilidade Masculina/tratamento farmacológico , Infertilidade Masculina/etiologia , Infertilidade Masculina/prevenção & controle , Testosterona , Inflamação
3.
Clin Res Hepatol Gastroenterol ; 47(10): 102231, 2023 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-37865226

RESUMO

INTRODUCTION: Linalool is a monoterpene that occurs naturally in various aromatic plants and is identified in our previous study as a potential candidate for protection against high-fat diet (HFD)-induced metabolic dysfunction-associated steatotic liver disease (MASLD). However, little is known about its direct effects on hepatic lipid metabolism and oxidative stress. Therefore, this study aims to investigate the therapeutic effect of linalool against MASLD and the underlying mechanism. METHODS: To establish a rat model of MASLD, male Wistar rats were fed HFD for 16 weeks and orally administered linalool (100 mg/kg body weight) for 45 days starting from week 14. RESULTS: Linalool significantly reduced HFD-induced liver lipid accumulation and restored altered adipokine levels. Mechanistically, linalool downregulated the mRNA expression of sterol regulatory element binding protein 1 and its lipogenesis target genes fatty acid synthase and acetyl-CoA carboxylase, and upregulated the mRNA expression of genes involved in fatty acid oxidation (peroxisome proliferator-activated receptor (PPAR)-alpha [PPAR-α], lipoprotein lipase and protein kinase B [Akt]) as well as the upstream mediators sirtuin 1 (Sirt1) and AMP-activated protein kinase (AMPK) in the liver of MASLD rats. In addition, linalool also curbed oxidative stress by increasing antioxidant enzymes and activating nuclear erythroid-2-related factor 2 (Nrf-2) and its downstream target genes involved in antioxidant properties. CONCLUSION: Therefore, this study concludes that linalool attenuates lipid accumulation in the liver by inhibiting de novo lipogenesis, promoting fatty acid oxidation, and attenuating oxidative stress by regulating Sirt1/Akt/PPRA-α/AMPK and Nrf-2/ HO-1 signaling pathways.


Assuntos
Fígado Gorduroso , Hepatopatia Gordurosa não Alcoólica , Ratos , Animais , Sirtuína 1/metabolismo , Sirtuína 1/farmacologia , Sirtuína 1/uso terapêutico , Proteínas Proto-Oncogênicas c-akt , Proteínas Quinases Ativadas por AMP/metabolismo , Antioxidantes/uso terapêutico , Receptores Ativados por Proliferador de Peroxissomo/metabolismo , Receptores Ativados por Proliferador de Peroxissomo/farmacologia , Receptores Ativados por Proliferador de Peroxissomo/uso terapêutico , Ratos Wistar , Fígado/metabolismo , Metabolismo dos Lipídeos , Transdução de Sinais , Estresse Oxidativo , Ácidos Graxos , Lipídeos , RNA Mensageiro/metabolismo , Hepatopatia Gordurosa não Alcoólica/tratamento farmacológico
4.
Osteoarthritis Cartilage ; 29(8): 1181-1192, 2021 08.
Artigo em Inglês | MEDLINE | ID: mdl-33915295

RESUMO

OBJECTIVE: To delineate the activities of decorin and biglycan in the progression of post-traumatic osteoarthritis (PTOA). DESIGN: Three-month-old inducible biglycan (BgniKO) and decorin/biglycan compound (Dcn/BgniKO) knockout mice were subjected to the destabilization of the medial meniscus (DMM) surgery to induce PTOA. The OA phenotype was evaluated by assessing joint structure and sulfated glycosaminoglycan (sGAG) staining via histology, surface collagen fibril nanostructure and calcium content via scanning electron microscopy, tissue modulus via atomic force microscopy-nanoindentation, as well as subchondral bone structure and meniscus ossification via micro-computed tomography. Outcomes were compared with previous findings in the inducible decorin (DcniKO) knockout mice. RESULTS: In the DMM model, BgniKO mice developed similar degree of OA as the control (0.44 [-0.18 1.05] difference in modified Mankin score), different from the more severe OA phenotype observed in DcniKO mice (1.38 [0.91 1.85] difference). Dcn/BgniKO mice exhibited similar histological OA phenotype as DcniKO mice (1.51 [0.97 2.04] difference vs control), including aggravated loss of sGAGs, salient surface fibrillation and formation of osteophyte. Meanwhile, Dcn/BgniKO mice showed further cartilage thinning than DcniKO mice, resulting in the exposure of underlying calcified tissues and aberrantly high surface modulus. BgniKO and Dcn/BgniKO mice developed altered subchondral trabecular bone structure in both Sham and DMM groups, while DcniKO and control mice did not. CONCLUSION: In PTOA, decorin plays a more crucial role than biglycan in regulating cartilage degeneration, while biglycan is more important in regulating subchondral bone structure. The two have distinct activities and modest synergy in the pathogenesis of PTOA.


Assuntos
Biglicano/deficiência , Decorina/deficiência , Progressão da Doença , Osteoartrite/patologia , Animais , Biglicano/genética , Osso Esponjoso/patologia , Cartilagem Articular , Decorina/genética , Modelos Animais de Doenças , Meniscos Tibiais/patologia , Camundongos Knockout , Ossificação Heterotópica/patologia , Osteoartrite/genética , Osteófito/patologia , Lesões do Menisco Tibial/patologia
6.
J Food Biochem ; 44(11): e13450, 2020 11.
Artigo em Inglês | MEDLINE | ID: mdl-32839989

RESUMO

In this study, the cardioprotective effects of partially purified phenolic fraction of Kedrostis foetidissima leaves (PFK) were evaluated in isoproterenol (ISO)-induced myocardial infarction rat model. ISO induction to experimental rats for two consecutive days significantly increased the levels of triglycerides, cholesterol, phospholipids, free fatty acids, low-density lipoproteins, and cardiac biomarker enzymes, and decreased the levels of high-density lipoproteins and antioxidant enzyme activity. Pretreatment of experimental rats with PFK for 45 days led to a significant elevation in antioxidant enzyme activity. PFK-pretreated rats exhibited significantly reduced levels of circulating lipids and cardiac-specific biomarker enzymes compared to ISO-treated rats. Thus, the present study demonstrated that PFK ameliorated ISO-induced cardiotoxicity through the augmentation of the endogenous cardiac antioxidant system, thereby modulating the lipid peroxidation caused by ISO-induced free radicals, and prevented the myocardial damage, which was confirmed through histopathological analysis. PRACTICAL APPLICATIONS: Kedrostis foetidissima is edible medicinal plant and phenolic fraction extracted from the leaves of this plant may help the common man in the protection of heart. The phenolic fraction shows significant antioxidant activity, so this might be referred to as dietary supplement and also helps to develop new pharmaceutical formulations.


Assuntos
Antioxidantes , Cardiotoxicidade , Extratos Vegetais , Folhas de Planta , Animais , Antioxidantes/farmacologia , Cardiotoxicidade/tratamento farmacológico , Cucurbitaceae , Isoproterenol/toxicidade , Extratos Vegetais/farmacologia , Ratos , Ratos Wistar
7.
Int J Biol Macromol ; 136: 368-376, 2019 Sep 01.
Artigo em Inglês | MEDLINE | ID: mdl-31207327

RESUMO

Misfolding of the cellular prion protein (PrPC) into ß-sheet-rich scrapie form (PrPSc) is associated with transmissible spongiform encephalopathies. A point mutation F198S is responsible for the development of a rare inherited Gerstmann-Straussler-Scheinker disease caused by the aggregation of PrPC. Thus, identification and the structural characterization of aggregation-prone regions are essential to delineate the conversion of PrPC to the disease-associated PrPSc upon F198S mutation. In the present study, molecular dynamics simulations on the wild-type PrP (WT-PrP) and its mutant were performed to explore the structural basis responsible for aggregation driven by the mutation. Secondary structure analysis revealed that the mutant exhibited a partial unfolding on α2 and the complete distortion in the 310-helix of the ß2-α2 loop. Remarkably, the ß2-α2 loop is in proximity to α3 attributed by the long-range hydrophobic interactions and such structural intimacy is not observed in the WT-PrP. Owing to this, the ß1-α1-ß2 regions have separated from α2-α3 domain resulting in the impairment on the hydrogen bond between α1 and α3. Thus, the present study provides a detailed structural description of the F198S mutant in line with previous experimental results and delivers insights into the structural basis responsible for the conversion of PrPC to the disease-associated PrPSc.


Assuntos
Simulação de Dinâmica Molecular , Proteínas PrPC/química , Proteínas PrPSc/química , Proteínas Priônicas/química , Ligação de Hidrogênio , Mutação , Proteínas Priônicas/genética , Conformação Proteica em alfa-Hélice , Domínios Proteicos , Redobramento de Proteína , Termodinâmica
8.
Int J Tuberc Lung Dis ; 23(4): 450-457, 2019 04 01.
Artigo em Inglês | MEDLINE | ID: mdl-31064624

RESUMO

BACKGROUND The association between respiratory impairment and tuberculosis (TB) treatment outcomes is not clear. METHODS We prospectively evaluated respiratory health status, measured using the Saint George's Respiratory Questionnaire (SGRQ), in a cohort of new adult pulmonary TB cases during and up to 18 months following treatment in India. Associations between total SGRQ scores and poor treatment outcomes of failure, recurrence and all-cause death were measured using multivariable Poisson regression. RESULTS We enrolled 455 participants contributing 619 person-years at risk; 39 failed treatment, 23 had recurrence and 16 died. The median age was 38 years (interquartile range 26-49); 147 (32%) ever smoked. SGRQ scores at treatment initiation were predictive of death during treatment (14% higher risk per 4-point increase in baseline SGRQ scores, 95%CI 2-28, P = 0.01). Improvement in SGRQ scores during treatment was associated with a lower risk of failure (1% lower risk for every per cent improvement during treatment, 95%CI 1-2, P = 0.05). Clinically relevant worsening in SGRQ scores following successful treatment was associated with a higher risk of recurrence (15% higher risk per 4-point increase scores, 95%CI 4-27, P = 0.004). CONCLUSION Impaired respiratory health status was associated with poor TB treatment outcomes. The SGRQ may be used to monitor treatment response and predict the risk of death in pulmonary TB. .


Assuntos
Nível de Saúde , Tuberculose Pulmonar/tratamento farmacológico , Adolescente , Adulto , Estudos de Coortes , Feminino , Seguimentos , Humanos , Índia , Masculino , Pessoa de Meia-Idade , Recidiva , Inquéritos e Questionários , Resultado do Tratamento , Tuberculose Pulmonar/mortalidade , Tuberculose Pulmonar/fisiopatologia , Adulto Jovem
9.
Genomics ; 111(4): 696-699, 2019 07.
Artigo em Inglês | MEDLINE | ID: mdl-29665417

RESUMO

Glaucoma is the second leading cause of blindness after cataract and is heterogeneous in nature. Employing a genetic approach for the detection of the diseased condition provides an advantage that the gene responsible for the disease can be identified by genetic test. The availability of predictive tests based on the published literature would provide a mechanism for early detection and treatment. The genotype and phenotype information could be a valuable source for predicting the risk of the disease. To this end, a web server has been developed, based on the genotype and phenotype of myocilin mutation, which were identified by familial linkage analysis and case studies. The proposed web server provides clinical data and severity index for a given mutation. The server has several useful options to help clinicians and researchers to identify individuals at a risk of developing the disease. Glaucoma Pred server is available at http://bioserver1.physics.iisc.ac.in/myocilin.


Assuntos
Proteínas do Citoesqueleto/genética , Proteínas do Olho/genética , Glaucoma de Ângulo Aberto/genética , Glicoproteínas/genética , Fenótipo , Polimorfismo Genético , Software , Genótipo , Glaucoma de Ângulo Aberto/epidemiologia , Glaucoma de Ângulo Aberto/patologia , Humanos
11.
Int J Tuberc Lung Dis ; 22(6): 686-694, 2018 06 01.
Artigo em Inglês | MEDLINE | ID: mdl-29862955

RESUMO

SETTING: Pre-diabetes mellitus (pre-DM) and DM increase the risk of developing tuberculosis (TB). Screening contacts of TB patients for pre-DM/DM and linking them to care may mitigate the risk of developing TB and improve DM management. OBJECTIVE: To measure the prevalence of pre-DM/DM and associated factors among the adult household contacts (HHCs) of pulmonary TB patients. METHODS: Between August 2014 and May 2017, adult HHCs of newly diagnosed adult PTB patients in Pune and Chennai, India, had single blood samples tested for glycosylated haemoglobin (HbA1c) at enrolment. DM was defined as previously diagnosed, self-reported DM or HbA1c 6.5%, and pre-DM as HbA1c between 5.7% and 6.4%. Latent tuberculous infection (LTBI) was defined as a positive tuberculin skin test (5 mm induration) or QuantiFERON® Gold In-Tube (0.35 international units/ml). RESULTS: Of 652 adult HHCs, 175 (27%) had pre-DM and 64 (10%) had DM. Forty (64%) HHCs were newly diagnosed with DM and 48 (75%) had poor glycaemic control (HbA1c 7.0%). Sixty-eight (22%) pre-DM cases were aged 18-34 years. Age 35 years, body mass index 25 kg/m2, chronic disease and current tobacco smoking were significantly associated with DM among HHCs. CONCLUSIONS: Adult HHCs of TB patients in India have a high prevalence of undiagnosed DM, pre-DM and LTBI, putting them at high risk for developing TB. Routine DM screening should be considered among all adult HHCs of TB.


Assuntos
Diabetes Mellitus/epidemiologia , Programas de Rastreamento/métodos , Estado Pré-Diabético/epidemiologia , Tuberculose/epidemiologia , Adolescente , Adulto , Busca de Comunicante/métodos , Estudos Transversais , Diabetes Mellitus/diagnóstico , Feminino , Hemoglobinas Glicadas/análise , Humanos , Índia/epidemiologia , Tuberculose Latente/diagnóstico , Tuberculose Latente/epidemiologia , Masculino , Pessoa de Meia-Idade , Estado Pré-Diabético/diagnóstico , Prevalência , Fatores de Risco , Tuberculose/diagnóstico , Tuberculose Pulmonar/diagnóstico , Tuberculose Pulmonar/epidemiologia , Adulto Jovem
12.
J Assoc Physicians India ; 65(2): 92-93, 2017 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-28457045

RESUMO

Metastatic prostatic carcinoma commonly involves bones and extra pelvic lymph nodes. CNS involvement is unusual and particularly the occurence of leptomeningeal metastasis is extremely rare, with few cases described in the literature.1 The reported incidence at autopsy vary from 0.6 to 4.4 percent.2 We report a 65 year old male who presented with multiple cranial nerve palsies due to leptomeningeal metastasis in carcinoma prostate treated with orchidectomy and planned for radiotherapy and antiandrogen therapy.


Assuntos
Adenocarcinoma/complicações , Doenças dos Nervos Cranianos/etiologia , Neoplasias Meníngeas/complicações , Neoplasias da Próstata/patologia , Adenocarcinoma/diagnóstico , Adenocarcinoma/secundário , Idoso , Humanos , Masculino , Neoplasias Meníngeas/diagnóstico , Neoplasias Meníngeas/secundário , Neoplasias da Próstata/diagnóstico
13.
Mol Biosyst ; 12(10): 3223-33, 2016 10 20.
Artigo em Inglês | MEDLINE | ID: mdl-27523988

RESUMO

The development of fatal transmissible spongiform encephalopathies (TSE) is associated with the conformational conversion of the normal cellular prion protein, PrP(C), into its pathogenic isoform, PrP(Sc). The present study revealed the structural consequences that induce the conversion of PrP(C)→ PrP(Sc) upon mutation V210I linked with genetic Creutzfeldt-Jakob disease (CJD) using the classical molecular dynamics (MD) approach. Similar to the experimental results, the mutant showed biased disruption in the local folding of α2 and the complete distortion of α3. In addition, substitution of bulkier Ile at position 210 induced reorientations of several residues that were the constituent of hydrophobic cores, thereby influencing α2-α3 inter-helical interactions. In addition, the ß2-α2 loop was greatly altered due to the loss of π-π interactions of the residue Tyr(169) with Phe(175), Tye(163), Tyr(162), and Tyr(218), facilitating more conformational flexibility, which may be involved in the conversion of PrP(C)→ PrP(Sc). This study afforded a detailed structure and dynamic properties of the mutant, which were consistent with the experimental results, providing an insight into the molecular basis for the conversion of PrP(C)→ PrP(Sc), which could be used for the development of antiprion drugs.


Assuntos
Modelos Moleculares , Mutação , Proteínas PrPC/química , Proteínas PrPC/genética , Proteínas PrPSc/química , Proteínas PrPSc/genética , Conformação Proteica , Humanos , Ligação de Hidrogênio , Dobramento de Proteína , Domínios e Motivos de Interação entre Proteínas , Relação Quantitativa Estrutura-Atividade
14.
Mol Biosyst ; 12(3): 850-9, 2016 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-26757617

RESUMO

Beta-2 microglobulin (ß2m) is an amyloidogenic protein belongs to the immunoglobulin superfamily, responsible for the dialysis-related amyloidosis (DRA). Misfolding of ß2m is a prerequisite to the formation of systemic amyloidosis that has an effect on the structure and function of the affected organ. The aim of our present study is to intensively explore the structural characterization of amyloid aggregation propensity of recently identified natural mutation D76N by applying the classical molecular dynamics (MD) approach. The MD result revealed that mutant D76N exhibited a wide variation in the evolutionarily conserved secondary structure profile. Due to an unsatisfied position of main chain donor/acceptor atoms that unable to form essential hydrogen bonds resulted to cause misfolding of mutant D76N by disrupting the local folding of ß-strands and turn region. Analysis of time evolution of various structural properties, especially those of the functionally important residues: aggregation determining, initiating, and gatekeeper residues gave some possible insights into the structural characteristics of the disease mutant D76N. In a nutshell, compared to the wild-type ß2m, aggregation promoting propensity of mutant D76N has established a long ß-strand D owing to an inward movement of residue, Asp(53). Besides, aggregation forming characteristic of the DE loop in mutant D76N showed greater flexibility along the first principal eigenvector that favored to enhance an unusual conformational dynamics may lead toward self-aggregation and amyloid fibrils.


Assuntos
Amiloide/química , Simulação de Dinâmica Molecular , Proteínas Mutantes/química , Agregados Proteicos , Microglobulina beta-2/química , Sequência de Aminoácidos , Ligação de Hidrogênio , Dados de Sequência Molecular , Análise de Componente Principal , Dobramento de Proteína , Estrutura Secundária de Proteína , Microglobulina beta-2/genética
16.
Spectrochim Acta A Mol Biomol Spectrosc ; 136 Pt C: 1803-6, 2015 Feb 05.
Artigo em Inglês | MEDLINE | ID: mdl-25467673

RESUMO

Pure CuO and Zn-doped CuO nanoparticles were synthesized from sol-gel process by reacting copper acetate monohydrate with a urea in distilled water at 80°C. The synthesized Samples were different concentrations but same annealing temperature at 400°C. The obtained samples were characterized by means of UV-visible spectroscopy (UV-vis), X-ray diffraction (XRD), Fourier transform-infrared spectroscopy (FT-IR), Field emission scanning electron microscopy (FE-SEM) and Energy dispersive X-ray spectroscopy (EDS). UV-visible technique used to measure the band gap of the synthesized samples. The XRD spectra of the synthesized samples confirmed the CuO nanoparticles with monoclinic structure. All the functional groups of the pure and doped synthesized samples were investigated by FT-IR analysis. The morphological and elemental estimation of the pure and Zn-doped synthesized samples were examined by FE-SEM with EDS.

17.
Inorg Chem ; 53(17): 9192-205, 2014 Sep 02.
Artigo em Inglês | MEDLINE | ID: mdl-25113575

RESUMO

The complexes [Pt(mdt)2] (4; mdt = methyldithiolene, [Me2C2S2](n-)), [Pt(adt)2] (5; adt = p-anisyldithiolene, [(MeO-p-C6H4)2C2S2](n-)), and [Pd(adt)2] (10) have been prepared in yields of ≥90% via transmetalation reactions with the corresponding [R2Sn(S2C2R'2)] complexes (R = (n)Bu, R' = Me; R = Me, R' = -C6H4-p-OMe, 3). Intraligand C-S and C-Cchelate bond lengths (~1.71 and ~1.40 Å, respectively) obtained by X-ray crystallography show these compounds to be comprised of radical monoanions mdt(•-) and adt(•-). The six-coordinate octahedral adducts [Pt(adt)2(dppe)] [6; dppe = 1,2-bis(diphenylphosphino)ethane], trans-[Pt(adt)2(PMe3)2] (8), and trans-[Pt(mdt)2(PMe3)2] (9) have also been prepared, and crystal structures reveal dithiolene ligands that are fully reduced ene-1,2-dithiolates (C-S and C-C(chelate) = ~1.77 and 1.35 Å, respectively). Reduction of the dithiolene ligand thus occurs to accommodate the +IV oxidation state typical of octahedral six-coordinate platinum. The cyclic voltammogram of 5 shows two fully reversible reductions at -0.11 and -0.84 V in CH2Cl2 (vs Ag/AgCl), attributed to successive (adt(•-) + e(-) → adt(2-)) processes, and a reversible oxidation at +1.01 V. The cyclic voltammogram of 9 shows two reversible oxidations at +0.38 and +0.86 V, which are assigned as successive (adt(2-) → adt(•-) + e(-)) oxidations. Consistent with their formulation as having fully reduced dithiolene ligands, the UV-vis spectra for 6, 8, and 9 show no low-energy absorptions below 700 nm, and the S K-edge XAS spectra of 6 and 8 show dithiolene sulfur that is reduced relative to that in 5. The introduction of PMe3 to 10 did not produce the palladium analogue of 8 but rather [Pd(adt)(PMe3)2] (11). The reaction of [PdCl2(PPh3)2] with Li2(mdt) produced a mixture of [Pd(mdt)(PPh3)2] (12, 20%) and [(Ph3P)Pd(µ-1,2-mdt-S,S':S)2Pd(PPh3)] (13, 28%), with the latter having C2 symmetry with a Pd2S2 core structure folded along the S···S axis.

18.
Mol Biosyst ; 10(7): 1869-80, 2014 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-24770789

RESUMO

X-linked lymphoproliferative (XLP) syndrome is an extremely rare inherited immunodeficiency disease characterized by severe immune dysregulation caused by mutations in signaling lymphocyte activation molecule (SLAM) associated protein (SAP) gene. The XLP syndrome was manifested due to dysfunction of SAP as a result of amino acid substitution. Hence, to understand the molecular aspects of the XLP syndrome, we structurally characterized two observed mutations, R32Q and T53I on SAP through the systematic molecular dynamics (MD) approach. Our MD analysis showed that mutant structures elucidated an atomic level variation influenced by mutations that substantially altered the residual flexibility and more importantly the hot spot residues as well in unbound and bound systems. In addition, change in residual flexibility of mutant structures showed an unusual conformational behavior associated with their molecular recognition function compared to the wild-type SAP in both systems. Besides, both mutant structures established different secondary structural profiles during the course of the simulation period in both systems. Moreover, the docking analysis revealed that mutant R32Q and T53I structures displayed remarkably reduced levels of binding affinity to the unphosphorylated SLAM peptide with respect to their docking scores. Collectively, our findings provide knowledge to understand the structural and functional relationship of disease-causing mutations, R32Q and T53I on SAP as well as gain further insights into the molecular pathogenesis of the XLP syndrome.


Assuntos
Substituição de Aminoácidos , Antígenos CD/química , Peptídeos e Proteínas de Sinalização Intracelular/química , Peptídeos e Proteínas de Sinalização Intracelular/genética , Peptídeos/metabolismo , Receptores de Superfície Celular/química , Antígenos CD/metabolismo , Humanos , Transtornos Linfoproliferativos/genética , Modelos Moleculares , Conformação Molecular , Simulação de Acoplamento Molecular , Simulação de Dinâmica Molecular , Análise de Componente Principal , Ligação Proteica , Estrutura Secundária de Proteína , Receptores de Superfície Celular/metabolismo , Proteína Associada à Molécula de Sinalização da Ativação Linfocitária , Membro 1 da Família de Moléculas de Sinalização da Ativação Linfocitária
19.
Artigo em Inglês | MEDLINE | ID: mdl-24412789

RESUMO

The uncapped and capped CuO nanoparticles were synthesized by sol-gel process. Ethylene diamine tetra acetic acid (EDTA) used as a capping agent to control the size and morphology of the CuO nanoparticles. Control the nanostructure and optical properties of CuO nanoparticles are deliberate by using capping agent. The obtained samples were characterized by means of UV-Visible spectroscopy (UV-Vis), X-ray diffraction (XRD), Fourier transform-infrared spectroscopy (FT-IR), Scanning electron microscopy (SEM) along with energy dispersive X-ray spectroscopy (EDS). UV-Visible technique used to measure the band gap of the synthesized samples. The XRD spectra of the synthesized samples confirmed the CuO nanoparticles with monoclinic structure. The occurrences of capping agent have been analyzed by Fourier transform-infrared spectroscopy (FT-IR). The FT-IR study revealed that the transmittance peaks at 501cm(-1) and 592cm(-1) were CuO stretching mode, and 677cm(-1) was CuO monoclinic phase of the uncapped CuO nanoparticles. Further, SEM study find out the morphology of the synthesized samples, where the surface morphology changes occurred with an addition of capping agent. Moreover, the capping mechanism has been discussed based on the chemical reaction between the CuO nanoparticles and the functional groups of the capping agent.


Assuntos
Cobre/química , Ácido Edético/química , Nanopartículas/química , Nanopartículas/ultraestrutura , Tamanho da Partícula , Transição de Fase , Propriedades de Superfície , Difração de Raios X
20.
Inorg Chem ; 53(1): 308-17, 2014 Jan 06.
Artigo em Inglês | MEDLINE | ID: mdl-24320788

RESUMO

A series of reports describing the syntheses and structures of [MCl2(diazadiene)] (M = Cr, Mo, W) complexes is reassessed in the context of known chemistry of low-valent Group VI metal complexes, crystallographic trends such as M-Cl bond lengths and unit cell volumes, and calculated metal-ligand bond lengths. Crystallographic data and computational results are inconsistent with any of these species being second or third row transition metal complexes. A review of the crystallographic information files accompanying the [MCl2(diazadiene)] (M = Mo, W) published structures reveals that the metal atoms were inappropriately treated with partial site occupancy factors (0.775 for Mo; 0.4005 and 0.417 for W), the effect of which was to manifest lighter-element behavior and better refinement in accord with the metal atoms' correct identity. A deliberate synthesis and characterization by X-ray diffraction of [ZnCl2((Mes)dad(Me))] ((Mes)dad(Me) = 1,4-bis(2,4,6-trimethylphenyl)-2,3-dimethyl-1,4-diaza-1,3-butadiene) are reported. Refinement of this structure with the same combination of second or third row metal and offsetting partial site occupancy is shown to provide final refinement statistics essentially the same as with the correct model employing M = Zn at site occupancy 1.00. Use of the published method for synthesis of [WCl2(diazadiene)] with (Mes)dad(Me) and [WBr4(MeCN)2] in lieu of [WCl4(MeCN)2] is shown to produce [ZnBr2((Mes)dad(Me))], which has also been characterized by X-ray diffraction. It is concluded that the unusual putative 12-electron [MCl2(diazadiene)] (M = Cr, Mo, W) complexes are in all cases the corresponding [ZnCl2(diazadiene)] complexes, Zn having been commonly employed as reducing agent in their synthesis.

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