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1.
Cureus ; 16(3): e55642, 2024 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-38586766

RESUMO

This case report discusses the intricate diagnostic and therapeutic challenges faced by a 23-year-old Indian male who presented with altered consciousness, a holo-cranial headache, right-sided hemiparesis, and subsequent neurological symptoms. The patient's dietary habits, leading to vitamin B12 and folic acid deficiencies resulting in hyperhomocysteinemia, along with binge alcohol drinking leading to dehydration, were identified as the main causes of cerebral venous sinus thrombosis (CVST) in this case. The case was complicated by an additional cerebral hemorrhage. The patient received a comprehensive treatment regimen involving antiepileptic medications, intravenous fluids, and anticoagulation therapy. A decline in the Glasgow Coma Scale score prompted further interventions. Collaborative decision-making, involving neurologists, neurosurgeons, and the patient's relatives, steered the treatment course, ultimately favoring continued medical management over decompression surgery. Notably, the patient exhibited remarkable progress in mobility, achieving the ability to walk with support by the end. This case report contributes valuable insights to the understanding of CVST, emphasizing the significance of nutritional considerations, especially in vegetarians, and underscoring the importance of thorough diagnostic evaluations in complex clinical scenarios.

2.
Biomolecules ; 14(2)2024 Jan 23.
Artigo em Inglês | MEDLINE | ID: mdl-38397377

RESUMO

A monolayer of endothelial cells (ECs) lines the lumen of blood vessels and, as such, provides a semi-selective barrier between the blood and the interstitial space. Compromise of the lung EC barrier due to inflammatory or toxic events may result in pulmonary edema, which is a cardinal feature of acute lung injury (ALI) and its more severe form, acute respiratory distress syndrome (ARDS). The EC functions are controlled, at least in part, via epigenetic mechanisms mediated by histone deacetylases (HDACs). Zinc-dependent HDACs represent the largest group of HDACs and are activated by Zn2+. Members of this HDAC group are involved in epigenetic regulation primarily by modifying the structure of chromatin upon removal of acetyl groups from histones. In addition, they can deacetylate many non-histone histone proteins, including those located in extranuclear compartments. Recently, the therapeutic potential of inhibiting zinc-dependent HDACs for EC barrier preservation has gained momentum. However, the role of specific HDAC subtypes in EC barrier regulation remains largely unknown. This review aims to provide an update on the role of zinc-dependent HDACs in endothelial dysfunction and its related diseases. We will broadly focus on biological contributions, signaling pathways and transcriptional roles of HDACs in endothelial pathobiology associated mainly with lung diseases, and we will discuss the potential of their inhibitors for lung injury prevention.


Assuntos
Células Endoteliais , Histona Desacetilases , Histona Desacetilases/metabolismo , Células Endoteliais/metabolismo , Epigênese Genética , Zinco/metabolismo , Inibidores de Histona Desacetilases/farmacologia , Pulmão/metabolismo , Histonas/metabolismo
3.
Biomedicines ; 11(6)2023 Jun 05.
Artigo em Inglês | MEDLINE | ID: mdl-37371733

RESUMO

Vascular barrier dysfunction is characterized by increased permeability and inflammation of endothelial cells (ECs), which are prominent features of acute lung injury (ALI), acute respiratory distress syndrome (ARDS), and sepsis, and a major complication of the SARS-CoV-2 infection and COVID-19. Functional impairment of the EC barrier and accompanying inflammation arises due to microbial toxins and from white blood cells of the lung as part of a defensive action against pathogens, ischemia-reperfusion or blood product transfusions, and aspiration syndromes-based injury. A loss of barrier function results in the excessive movement of fluid and macromolecules from the vasculature into the interstitium and alveolae resulting in pulmonary edema and collapse of the architecture and function of the lungs, and eventually culminates in respiratory failure. Therefore, EC barrier integrity, which is heavily dependent on cytoskeletal elements (mainly actin filaments, microtubules (MTs), cell-matrix focal adhesions, and intercellular junctions) to maintain cellular contacts, is a critical requirement for the preservation of lung function. EC cytoskeletal remodeling is regulated, at least in part, by Ser/Thr phosphorylation/dephosphorylation of key cytoskeletal proteins. While a large body of literature describes the role of phosphorylation of cytoskeletal proteins on Ser/Thr residues in the context of EC barrier regulation, the role of Ser/Thr dephosphorylation catalyzed by Ser/Thr protein phosphatases (PPases) in EC barrier regulation is less documented. Ser/Thr PPases have been proposed to act as a counter-regulatory mechanism that preserves the EC barrier and opposes EC contraction. Despite the importance of PPases, our knowledge of the catalytic and regulatory subunits involved, as well as their cellular targets, is limited and under-appreciated. Therefore, the goal of this review is to discuss the role of Ser/Thr PPases in the regulation of lung EC cytoskeleton and permeability with special emphasis on the role of protein phosphatase 1 (PP1) and protein phosphatase 2A (PP2A) as major mammalian Ser/Thr PPases. Importantly, we integrate the role of PPases with the structural dynamics of the cytoskeleton and signaling cascades that regulate endothelial cell permeability and inflammation.

4.
Artigo em Inglês | MEDLINE | ID: mdl-34387173

RESUMO

OBJECTIVE: To assess the safety and efficacy of Novel tapered (BioMime™ Morph) sirolimus- eluting stent (SES) for left main PCI in a real-world scenario. BACKGROUND: Currently, no data is available on clinical usefulness of tapered ultrathin stents in left main PCI. METHODS: This was a prospective, non-randomised, single centre study carried out between February 2018 and May 2020 at a tertiary cardiac care centre in southern India. The study included patients treated with BioMime Morph tapered stent for distal de novo LMB lesion or ostial LAD/LCX lesions with significant size disparity between reference segments based on the eligibility criteria. Primary endpoint of the study was the cumulative incidence of major adverse cardiovascular events (MACE) composed of cardiac death, myocardial infarction, and clinically driven target-lesion revascularisation at follow-up. RESULTS: A total of 41 patients (average age of 54.83±9.81 years) were included in the study. Average SS-2 score was 23.17±5.42. Majority of the lesions (n=31; 75.61%) were of medina class (0.1.0). Provisional single stent strategy was adopted for treatment of LMB lesions. TIMI flow-3 was achieved in 40 patients (97.56%). Median clinical follow-up was 20 months (range 6-34 months). There was no periprocedural complication or MACE during follow-up. CONCLUSION: Tapered stents may be an acceptable alternative for LM intervention in an anatomical subset of patients with tapered vessels.


Assuntos
Doença da Artéria Coronariana , Stents Farmacológicos , Intervenção Coronária Percutânea , Doença da Artéria Coronariana/cirurgia , Stents Farmacológicos/efeitos adversos , Estudos de Viabilidade , Humanos , Pessoa de Meia-Idade , Estudos Prospectivos , Fatores de Risco , Stents/efeitos adversos , Centros de Atenção Terciária , Resultado do Tratamento
5.
Indian Heart J ; 72(5): 394-397, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-33189200

RESUMO

AIMS: To study the risk factors, clinical and angiographic profile of Indian rural youth (under 35yrs) presenting with Premature Coronary Artery Disease (PCAD). SUBJECTS: and Methods: The PCAD registry had 1628 patients who were aged below 35 years, of which 681 patients satisfied the entry criteria. The data was analysed by statistical software R version 3.5.0. RESULTS: The study enrolled 681 patients after satisfying the entry criteria. The mean age of patients was 30.85 years. There were 405 (59.5%) aged between 30 and 35 yrs, 205 (30.1%) between 25 and 30 yrs, 64 (9.4%) between 20 and 25 yrs and 7 (1.0%) were aged less than 20 yrs. Majority of them were males, 617 (90.6%). Nearly 411 (60.4%) were smokers, 56patients (8.2%) were diabetics and 97 (14.2%) were hypertensives. Around 441 (64.8%) patients had low HDL cholesterol levels and 218 (32.0%) had elevated triglyceride levels. Abdominal obesity was seen in 443 (65.1%) patients. Most common clinical presentation was ST elevation myocardial infarction (STEMI) seen in 536 (78.7%) patients. Around 40% patients had recanalized/non obstructive/thrombotic/normal coronaries on coronary angiogram. CONCLUSIONS: Conventional risk factors such as smoking, low HDL levels and abdominal obesity play a major role in the causation of premature coronary artery disease among the rural youth. Thrombotic milieu in the coronaries was commonly noted in coronary angiograms. Lack of awareness, combined with urbanisation of rural lifestyle could be responsible for increasing incidence of premature coronary artery disease in rural youth.


Assuntos
Doença da Artéria Coronariana/epidemiologia , Sistema de Registros , Medição de Risco/métodos , População Rural , Adulto , Angiografia Coronária , Doença da Artéria Coronariana/diagnóstico , Feminino , Humanos , Índia/epidemiologia , Masculino , Prevalência , Estudos Prospectivos , Fatores de Risco , Adulto Jovem
6.
J Pharmacol Toxicol Methods ; 106: 106914, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32828949

RESUMO

INTRODUCTION: Development of therapy options for treatment of type 1 diabetes mellitus is hampered by non-availability of appropriate experimental models that can exactly mimic the in vivo situation. Apoptosis of beta cells by T cells and cytokine action leads to loss of beta cells. We propose a simple and elegant model using cytokine cocktail of TNF-α, IFN-γ and IL-1ß, the major cytokines responsible for apoptosis in Min6 beta cell line. METHODS: A cocktail of TNF-α, IFN-γ and IL-1ß was used to induce apoptosis in Min6 beta cell line. Apoptosis was assessed by flow cytometry using CytoFLEX (Beckman Coulter). The destruction of beta cells is through production of nitric oxide (NO), oxidative stress and change in mitochondrial membrane permeability. NO was measured using Griess reagent. Oxidative stress was assessed using 2',7'-dichlorofluorescein diacetate, a cell-permeable fluorogenic dye and mitochondrial membrane potential was determined on the basis of retention of rhodamine 123 using flow cytometer. RESULTS AND DISCUSSION: Very low concentration of the cocktail viz. TNF-α 25 ng/ml, IFN-γ 25 ng/ml and IL-1ß 50 ng/ml has demonstrated effective early and late apoptosis in as short a time period as 6 h. The experimental model used demonstrated 1.5 fold higher production of NO, 1.2 fold increased oxidative stress and lower mitochondrial membrane potential as compared to the positive control used. Hence the above model can be easily used for assessment and screening of drugs that can prevent apoptosis of beta cells and stop progression of type 1 diabetes.


Assuntos
Apoptose/fisiologia , Diabetes Mellitus Tipo 1/tratamento farmacológico , Células Secretoras de Insulina/patologia , Animais , Apoptose/efeitos dos fármacos , Técnicas de Cultura de Células/métodos , Linhagem Celular Tumoral , Meios de Cultura/metabolismo , Diabetes Mellitus Tipo 1/patologia , Avaliação Pré-Clínica de Medicamentos/métodos , Estudos de Viabilidade , Citometria de Fluxo , Humanos , Hipoglicemiantes/farmacologia , Hipoglicemiantes/uso terapêutico , Células Secretoras de Insulina/efeitos dos fármacos , Células Secretoras de Insulina/metabolismo , Interferon gama/metabolismo , Interleucina-1beta/metabolismo , Potencial da Membrana Mitocondrial/efeitos dos fármacos , Potencial da Membrana Mitocondrial/fisiologia , Camundongos , Óxido Nítrico/metabolismo , Estresse Oxidativo , Espécies Reativas de Oxigênio/metabolismo , Proteínas Recombinantes/metabolismo , Fator de Necrose Tumoral alfa/metabolismo
7.
Mol Cell Biochem ; 459(1-2): 61-71, 2019 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-31102033

RESUMO

Hyperglycemia in diabetes causes protein glycation that leads to oxidative stress, release of cytokines, and establishment of secondary complications such as neuropathy, retinopathy, and nephropathy. Several other metabolic disorders, stress, and inflammation generate free radicals and oxidative stress. It is essential to study whether oxidative stress independently enhances protein glycation leading to rapid establishment of secondary complications. Oxidative stress was experimentally induced using rotenone and Fenton reagent for in vivo and in vitro studies, respectively. Results showed significant increase in the rate of modification of BSA in the form of fructosamine and protein-bound carbonyls in the presence of fenton reagent. Circular dichroism studies revealed gross structural changes in the reduction of alpha helix structure and decreased protein surface charge was confirmed by zeta potential studies. Use of rotenone demonstrated enhanced AGE formation, ROS generation, and liver and kidney tissue glycation through fluorescence measurement. Similar findings were also observed in cell culture studies. Use of aminoguanidine, a protein glycation inhibitor, demonstrated reduction in these changes; however, a combination of aminoguanidine along with vitamin E demonstrated better amelioration. Thus, oxidative stress accelerates the process of protein glycation causing gross structural changes and tissue glycation in insulin-independent tissues. Use of antioxidants and protein glycation inhibitors in combination are more effective in preventing such changes and could be an effective therapeutic option for preventing establishment of secondary complications of diabetes.


Assuntos
Antioxidantes/farmacologia , Produtos Finais de Glicação Avançada/antagonistas & inibidores , Guanidinas/farmacologia , Estresse Oxidativo/efeitos dos fármacos , Rotenona/farmacologia , Animais , Complicações do Diabetes/metabolismo , Complicações do Diabetes/patologia , Complicações do Diabetes/prevenção & controle , Produtos Finais de Glicação Avançada/metabolismo , Masculino , Ratos , Ratos Wistar , Espécies Reativas de Oxigênio/metabolismo
8.
Life Sci ; 218: 8-15, 2019 Feb 01.
Artigo em Inglês | MEDLINE | ID: mdl-30553872

RESUMO

AIMS: Prediabetes manifests several years earlier, before it progresses to diabetes. It is essential to track the earliest metabolic changes occurring in the prediabetic state and to understand the precise mechanism of how diabetes is initiated. MAIN METHODS: Alpha glucosidase was isolated from rat intestine and assayed using maltose as substrate. In vitro glycation of the enzyme was studied using varying fructose content through measurement of fructosamine, general and specific fluorescence. In vivo experiments were carried out through feed of 4 g fructose per day. Protein expression was studied using western blot and mRNA expression using RT-PCR method. KEY FINDINGS: Fructose inhibits alpha glucosidase to the extent of 48.97% in 4 h at 2.5 M concentration. In vivo studies demonstrated an inhibition of 56.96% in three days. Activity was found to rise by seven days and normalized by 10 days. Protein expression was found to increase by 10.56 fold and SI mRNA by 41.84 fold on 10 days of fructose feed. Long term fructose feed for 60 days demonstrated increase in alpha glucosidase activity by 2.12 fold and increase in postprandial glucose spike. SIGNIFICANCE: Glycation of alpha glucosidase causes inhibition of the enzyme activity leading to compensation through higher protein expression. Long term fructose feed leads to more than two fold increase in enzyme activity causing postprandial spikes and ultimately manifesting as diabetes mellitus.


Assuntos
Glicemia/análise , Frutose/farmacologia , Intestinos/efeitos dos fármacos , Intestinos/enzimologia , Estado Pré-Diabético/fisiopatologia , alfa-Glucosidases/metabolismo , Animais , Frutose/administração & dosagem , Inibidores de Glicosídeo Hidrolases/farmacologia , Glicosilação , Masculino , Estado Pré-Diabético/induzido quimicamente , Processamento de Proteína Pós-Traducional , Ratos , Ratos Wistar , alfa-Glucosidases/química
9.
J Org Chem ; 83(24): 15155-15169, 2018 12 21.
Artigo em Inglês | MEDLINE | ID: mdl-30525618

RESUMO

A new synthesis protocol for the preparation of hitherto unknown 1',5'-anhydro-4'-amino-trityl/MMTr hexitol nucleosides has been developed. Key steps in the synthesis of the pyrimidine analogues (U and C) include the regioselective d- allo-hexitol oxirane and 2',4'-anhydronucleoside ring opening by uracil and azide, respectively. A different strategy using a regioselective epoxide ring opening of d- gulo-oxirane, followed by a SN2 type of azidation reaction, has been adopted for the purine analogues (A and G). These compounds can be easily converted to 6'-phosphoramidites for the solid-phase synthesis of N4' → P6' phosphoramidates of amino hexitol nucleic acids (AHNA).


Assuntos
Oligonucleotídeos/química , Oligonucleotídeos/síntese química , Álcoois Açúcares/química , Técnicas de Química Sintética , Compostos de Epóxi/química , Estereoisomerismo
10.
Chemistry ; 24(54): 14335-14340, 2018 Sep 25.
Artigo em Inglês | MEDLINE | ID: mdl-30117206

RESUMO

Controlling the self-assembly of giant molecular building blocks into complex architectures with similar hierarchy to biological species remains a major challenge in supramolecular chemistry. Akin to protein structure, here we present the self-assembly of giant molecular nanocapsules into supramolecular coordination polymers with controlled hierarchy from primary to secondary and tertiary structures. First, we successfully prepared discrete nanocapsules (secondary structures) consisting of multicomponents, such as organic macrocycles and metal-based secondary building units (primary structures). Second, these nanocapsules can self-organize into various 2D and 3D supramolecular coordination polymers (tertiary structures) through coordination-driven assembly. The periphery 24 flexible alkyl chains and 24 metal ions available for potential coordination make these nanocapsules comparable to functionalized solid nanoparticles with non-specific binding sites at the surface and allow the nanocapsules to self-adjust their orientations and coordination modes to facilitate the self-assembly process. This study sheds light on the self-assembly of giant building units with complex molecular structures and opens up possibilities for the design of new hierarchical architectures with innovative properties and functions in many applications such as biomimics, biomedicine, and molecular devices.

11.
J Ethnopharmacol ; 222: 121-132, 2018 Aug 10.
Artigo em Inglês | MEDLINE | ID: mdl-29698774

RESUMO

ETHNOPHARMACOLOGICAL RELEVANCE: Hymenocallis littoralis (Jacq.) Salisb. has been referred as beach spider lily and commonly known for its rich phytochemical diversity. Phytochemicals such as alkaloids, volatile constituents, phenols, flavonoids, flavonols extracted from different parts of these plants like bulbs, flowers, leaf, stem and root had been used in folk medicines from ancient times because of their excellent antimicrobial and antioxidant properties. The leaf and bulb extract of H. littoralis plant was traditionally used for wound healing. Alkaloids extracted from bulb of this plant possess anti-viral, anti-neoplastic and cytotoxic properties. However, these phytochemicals have also shown antibiofilm activity, which is considered as one of the important factor accountable for the drug resistance in microorganisms. Thus, the investigation of medicinal properties of H. littoralis could be useful to control biofilm producing pathogens. AIM OF THE STUDY: Explore antimicrobial, antibiofilm and antioxidant potentials of H. littoralis against pathogenic microorganisms using experimental and computational biology approach. MATERIALS AND METHODS: Phytochemical extraction from dried powder of H. littoralis leaves was done by solvent extraction using methanol. Antimicrobial and antibiofilm activities of leaves extract were carried out using agar well diffusion method, growth curve, minimum inhibitory concentration (MIC) and Scanning Electron Microscopy (SEM). Liquid Chromatography and Mass Spectroscopy (LCMS) technique was used for the identification of phytochemicals. Molecular docking studies of antibiofilm agents with adhesin proteins were performed using Autodock 4.2. Antioxidant activity of extract was carried out by FRAP assay. The noxious effect of extract was investigated by histological studies on rat skin. RESULTS: The preliminary phytochemical analysis of methanolic leaves extract revealed the presence of alkaloids, flavonoids, terpenoid, glycosides, terpene, terpenoids and phenolics. The various phytochemicals such as Apigenin 7-(4'', 6'' diacetylalloside)-4'- alloside, Catechin 7-O- apiofuranoside, Emodic acid, Epicatechin 3-O- ß-D-glucopyranoside, 4 - Methylesculetin, Methylisoeugenol, Quercetin 5,7,3',4'-tetramethyl ether 3-rutinoside, 4 - Methylumbelliferyl ß-D- glucuronide were extracted, characterized and recognized from the leaves extract of H. littoralis. The identification of these phytochemicals was performed using LC-MS. The antimicrobial property of H. littoralis leaf extract was investigated against different pathogenic microorganisms. Out of these tested microorganisms, promising antibiofilm and antimicrobial activities were confirmed against S. aureus NCIM 2654 and C. albicans NCIM 3466 by using growth curve and SEM analysis. MIC of this leaf extract was identified as 45 µg/ml and 70 µg/ml for S. aureus NCIM 2654 and C. albicans NCIM 3466 respectively. The leaves extract also showed good antioxidant activity due to presence of phenols and flavonoids. Molecular docking of these identified antibiofilm components interacts with the active site residues of adhesin proteins, Sortase A and Als3 from S. aureus and C. albicans respectively. Histological studies of extracted phytochemicals revealed non-noxious effects on rat skin. CONCLUSION: Thus, the present study revealed that the leaves extract of H. littoralis contains various phytochemicals having good extent of antimicrobial, antibiofilm and antioxidant properties. The in-vitro and in-silico results would be useful to design new lead compounds against biofilm producing pathogenic microorganisms.


Assuntos
Amaryllidaceae , Anti-Infecciosos/farmacologia , Bactérias/efeitos dos fármacos , Fenômenos Fisiológicos Bacterianos/efeitos dos fármacos , Biofilmes/efeitos dos fármacos , Candida albicans/efeitos dos fármacos , Extratos Vegetais/farmacologia , Adesinas Bacterianas/metabolismo , Aminoaciltransferases/metabolismo , Animais , Anti-Infecciosos/análise , Antioxidantes/análise , Antioxidantes/farmacologia , Bactérias/crescimento & desenvolvimento , Proteínas de Bactérias/metabolismo , Biofilmes/crescimento & desenvolvimento , Candida albicans/crescimento & desenvolvimento , Candida albicans/fisiologia , Cisteína Endopeptidases/metabolismo , Proteínas Fúngicas/metabolismo , Masculino , Testes de Sensibilidade Microbiana , Microscopia Eletrônica de Varredura , Simulação de Acoplamento Molecular , Compostos Fitoquímicos/análise , Compostos Fitoquímicos/farmacologia , Extratos Vegetais/análise , Folhas de Planta , Ratos Wistar , Pele/efeitos dos fármacos
12.
Chem Commun (Camb) ; 54(6): 635-637, 2018 Jan 16.
Artigo em Inglês | MEDLINE | ID: mdl-29299555

RESUMO

We present here the preparation of a M18L6 hexameric metal-organic nanocapsule using a pyrogallol[3]resorcin[1]arene mixed macrocycle. The introduction of resorcinol moieties within the assembly leads to the formation of two open windows. This study demonstrates that introducing defects into the existing structure of nanocapsules may act as an effective method to tailor the composition and geometry, and introduce new properties.

13.
Chemistry ; 24(13): 3299-3304, 2018 Mar 02.
Artigo em Inglês | MEDLINE | ID: mdl-29291258

RESUMO

Crystalline hydrates of macrocyclic compounds such as pyroagllol[4]arenes (PgCs) and resorcin[4]arenes (RsCs) are rare owing to their lower water solubility. Functionalization of these macrocyclic compounds is an affordable way to enhance water solubility. However, functionalization also encounters the formation of multiple conformers and subsequent difficulty in purification of the product. Herein, four novel crystalline hydrates of functionalized PgCs and RsCs were synthesized. Formation of water channels and the effects of intermolecular interactions on the physical properties of these novel hydrates are discussed.

14.
Chem Commun (Camb) ; 53(89): 12144-12147, 2017 Nov 07.
Artigo em Inglês | MEDLINE | ID: mdl-29075728

RESUMO

Enhancing hierarchical structural complexities of metal-organic nanocapsules is an effective way of introducing new functions and properties. Herein, we present the synthesis of novel magnesium-seamed C-alkylpyrogallol[4]arene nanocapsules with hierarchical structural complexity via both exterior and endohedral functionalization. The exterior functionalization is realized by using a variety of covalently modified pyrogallol[4]arene ligands, while the endohedral functionalization is achieved via coordination-driven self-assembly. Especially, functionalization of nanocapsule interior by attaching a proline hexad via metal coordination will shed light to the design and synthesis of metal-organic species with heteroligated architectures.

15.
Chem Commun (Camb) ; 53(69): 9613-9615, 2017 Aug 24.
Artigo em Inglês | MEDLINE | ID: mdl-28809964

RESUMO

The solvothermal synthesis of two M7L2 metal-organic nanocapsules from C-alkyl pyrogallol[3]resorcin[1]arene is reported. Using mixed macrocycles as building blocks shows great potential in the discovery of new metal-organic nanocapsules with novel properties.

16.
Chemistry ; 23(35): 8520-8524, 2017 Jun 22.
Artigo em Inglês | MEDLINE | ID: mdl-28463424

RESUMO

Novel supramolecular nanocapsules based on metal-directed assembly have captured tremendous interest due to their applications in fields such as catalysis, selective gas adsorption, and biomedicine. Functionalization of metal-organic nanocapsules (MONCs) by using organic ligands with different pendant groups affords more complexity to the structure and may lead to novel properties. In this work, we report the solvothermal synthesis of a group of magnesium-based MONCs using C-alkylpyrogallol[4]arenes with varying alkyl chain lengths. The structures of these nanocapsules are characterized by single-crystal X-ray diffraction analysis. As expected, a progression in size of the nanocapsules is observed as the alkyl chain length increases. The effect of the chain length on the solubility of MONCs in water has been determined. This work shows the generality of the solvothermal approach for the synthesis of MONCs with different organic ligands and demonstrates that surface functionalization of MONCs may serve as an effective way to tailor their properties. The unique biocompatible nature and inherent large cavity of these magnesium-based MONCs make these nanocapsules promising for potential applications in biomedicine.

17.
Chem Commun (Camb) ; 53(31): 4312-4314, 2017 Apr 13.
Artigo em Inglês | MEDLINE | ID: mdl-28322394

RESUMO

The solvothermal synthesis of a metal-seamed hexameric nanocapsule from pyrogallol[4]arenes and magnesium is reported. The unique non-toxic and biocompatible nature of divalent magnesium cations in addition to the large inherent cavities make these nanocapsules promising for potential application in biomedicine. In addition, we show that these nanocapsules can form cocrystals with pyridine molecules through hydrogen bonding, which sheds light to cocrystallization of supramolecular nanocapsules with small pharmaceutics.

18.
J Am Chem Soc ; 139(8): 2920-2923, 2017 03 01.
Artigo em Inglês | MEDLINE | ID: mdl-28177625

RESUMO

The two-dimensional framework of nickel-seamed hexameric metal-organic nanocapsules has been synthesized by connecting the tailed hydroxyl groups of C-propan-3-ol pyrogallol[4]arene with adjacent hexameric capsules via nickel-hydroxyl coordination. In addition, functionalization of nanocapsules with multiple pyridine molecules at the capsule surface prevents them from assembling into hierarchical structures and leads to the formation of discrete nickel-seamed pyrogallol[4]arene nanocapsules. This work shows that surface functionalization of nanocapsules is an effective and innovative method of controlling the assembly of these nanometric building blocks.

19.
Bioorg Med Chem Lett ; 27(3): 574-577, 2017 02 01.
Artigo em Inglês | MEDLINE | ID: mdl-28043797

RESUMO

Activity-guided fractionations of the tunicate Pseudodistoma antinboja yielded four new compounds of the cadiolide class (cadiolides J-M, 1, 3-5) along with a known one (cadiolide H, 2). The structures were defined by spectroscopic methods including X-ray crystallographic analysis. These compounds were evaluated for their antibacterial activity and exhibited potent antibacterial activity against all of the drug resistant strains tested with MICs comparable to those of marketed drugs such as vancomycin and linezolid.


Assuntos
4-Butirolactona/análogos & derivados , Antibacterianos/farmacologia , Farmacorresistência Bacteriana/efeitos dos fármacos , Bactérias Gram-Positivas/efeitos dos fármacos , Urocordados/química , 4-Butirolactona/química , 4-Butirolactona/isolamento & purificação , 4-Butirolactona/farmacologia , Animais , Antibacterianos/química , Antibacterianos/isolamento & purificação , Relação Dose-Resposta a Droga , Testes de Sensibilidade Microbiana , Estrutura Molecular , República da Coreia , Relação Estrutura-Atividade
20.
Chemistry ; 22(43): 15202-15207, 2016 Oct 17.
Artigo em Inglês | MEDLINE | ID: mdl-27463858

RESUMO

Macrocyclic compounds, such as resorcin[4]arenes and pyrogallol[4]arenes, have proven to be useful building blocks in the construction of supramolecular organic frameworks (SOFs) because of their unique bowl-like shape and ability to interact through variety of intermolecular interactions. Herein, we report the synthesis and crystal structures of two functionalized resorcin[4]arenes and pyroagllol[4]arenes, 4-hydroxyphenylresorcin[4]arenes, and 4-hydroxyphenylpyrogallol[4]arenes. These phenyl-functionalized macrocycles usually have different conformers, such as cone, boat, chair, saddle, and diamond. The successful separation of predominant conformers from the crude product was carried out with solvent-extraction technique. The shape and molecular arrangement of these conformers in the individual crystal structure was verified with single-crystal X-ray diffraction studies.

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