Análise estrutural de ciclodextrinas: um estudo comparativo entre métodos teóricos clássicos e quânticos

Britto, Marta A. F. O.; Nascimento, Clébio S.; Santos, Hélio F. Dos

doi:10.1590/s0100-40422004000600008

Cited by 28 publications

(19 citation statements)

References 11 publications

(14 reference statements)

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“…BCD has several conformers; more information about their structures can be found in [45–49]. The conformer with a counterclockwise orientation of hydrogen bonds in both rims was chosen.…”

Section: Model Systems and Computational Detailsmentioning

confidence: 99%

Charge sensitivity approach to mutual polarization of reactants: molecular mechanics perspective

2013

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Charge sensitivity analysis (CSA) in force-field atoms resolution was applied to describe the mutual polarization of reactants as well as charge-transfer (CT) effects. An inclusion complex of β-cyclodextrin with salicylic acid was used as a model system. Three CSA models were taken into account and verified on a Born–Oppenheimer molecular dynamics (BOMD) trajectory. The models differed in terms of the equilibrium conditions imposed on the system. It was demonstrated that mutual polarization is an important source of stabilization, in contrast to the results obtained from static charge calculations. The energy lowering induced by CT was small and comparable to the CT stabilization that occurs in hydrogen-bonded systems. All models correctly described the main topological features of the BOMD energy surface. CSA in force-field atoms resolution qualitatively reproduced the charge reorganization accompanying hydrogen-bond formation. It was shown that CSA parameters are very sensitive to the bond formation process, which suggests that they could be applied in reactive force fields as detectors of newly formed chemical bonds.FigureFukui function detector of bond formation during molecular dynamics simulations of inclusion complex of b-cyclodextrin with salicylic acid.Electronic supplementary materialThe online version of this article (doi:10.1007/s00894-013-1757-4) contains supplementary material, which is available to authorized users.

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“…BCD has several conformers; more information about their structures can be found in [45–49]. The conformer with a counterclockwise orientation of hydrogen bonds in both rims was chosen.…”

Section: Model Systems and Computational Detailsmentioning

confidence: 99%

Charge sensitivity approach to mutual polarization of reactants: molecular mechanics perspective

2013

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“…142,143 A primeira referência sobre estas substâncias que mais tarde seriam classificadas como ciclodextrinas foi publicada por Villiers em 1891, em um estudo sobre a digestão do amido com o Bacillus amylobacter, o qual denominou de celulosina. 144 em 1903, Franz Schardinger identificou as ciclodextrinas como produtos resultantes da degradação do amido pela ação da enzima amilase ciclodextrina glicosil transferase (CGTase), 145 produzida pelo micro-organismo Bacillus macerans, capaz de romper um segmento da hélice do amido e unir as duas porções terminais deste fragmento numa única molécula cíclica.…”

Section: Ciclodextrinas (Cds)unclassified

Potencialidades e oportunidades na química da sacarose e outros açúcares

Ferreira¹,

Rocha²,

Silva³

2009

Quím. Nova

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Recebido em 15/1/09; aceito em 20/3/09; publicado na web em 2/4/09POTeNTIAlITy AND OPPORTUNITy IN The CheMISTRy OF SUCROSe AND OTheR SUGARS. Non-renewable biomass, such as coal, oil and natural gas are not only energy sources but also important starting materials for the production of a variety of chemicals ranging from gasoline, diesel oil and fine chemicals. In this regard, carbohydrates, the most abundant class of enantiopure organic compounds, are very suitable for generation of chemicals of great practical value. Their bulk-scale availability associated with low cost make them unique starting materials for organic preparative purpose. They are a most attractive alternative for construction of enantiopure target molecules by asymmetric synthesis. This review addresses, in addition to the use of low molecular weight carbohydrates, issues related to renewable biomass from photosynthesis and alternatives for the production of bulk and fine chemicals.Keywords: renewable biomass; sucrose; carbohydrates. introduçÃoA biomassa renovável terrestre é constituída de diversos produtos de baixas e altas massas moleculares como, por exemplo, carboidratos, aminoácidos, lipídios, e biopolímeros, como celulose, hemicelulose, quitina, amido, lignina e proteínas. estas biomassas são utilizadas na alimentação e para a produção de uma variedade de combustíveis, produtos químicos e produtos energéticos. O processamento da biomassa renovável abrange métodos biológicos, térmicos e/ou transformações químicas, além de tratamento mecânico para obter combustíveis sólidos, líquidos ou gasosos ou ainda produtos químicos de maior valor agregado.As biomassas não-renováveis, como carvão, petróleo e gás natural não são apenas materiais energéticos naturais, mas também são importantes insumos para a produção de uma grande variedade de produtos químicos que variam desde gasolina e óleo diesel 1-3 a insumos químicos e intermediários de produtos da química fina. 4,5 em termos energéticos, estas três biomassas são responsáveis por aproximadamente 75% da energia consumida correspondendo a 33, 24 e 19%, respectivamente.6 No entanto, como são recursos naturais fósseis finitos, fica evidente a grande necessidade de se desenvolver tecnologia para o aproveitamento das biomassas renováveis (esquema 1).As biomassas oriundas de fontes renováveis e o carvão foram as matérias-primas utilizadas, na mesma proporção, pela humanidade até cerca de 100 anos atrás. A partir do início do século 20 o gás natural e o petróleo tornaram-se os principais componentes da matriz energética mundial, alcançando seu ápice no século 21, o que reduziu drasticamente o uso das biomassas renováveis e paralelamente foram crescendo os níveis de CO 2 na atmosfera, devido à queima de gás e petróleo associado às devastações nas florestas.O petróleo tornou-se a biomassa de origem fóssil mais importante e as previsões de que sua produção não seria reduzida antes de 2050 fizeram com que as indústrias químicas continuassem baseando seus processos nesta matéria-prima. Como consequência, uma...

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“…An innovative strategy to overcome such challenges is their complexation with cyclodextrins; in other words, the formation of inclusion complexes to increase the water solubility of the plant compound [23]. This molecular property has enabled the use of cyclodextrins in different applications in science and technology, mainly in the pharmaceutical industry, by virtue of obtaining new drugs with different physical and chemical properties with the same active compounds [24].…”

Section: Introductionmentioning

confidence: 99%

Effect of α-Bisabolol and Its β-Cyclodextrin Complex as TetK and NorA Efflux Pump Inhibitors in Staphylococcus aureus Strains

et al. 2020

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Efflux pumps are proteins present in the plasma membrane of bacteria, which transport antibiotics and other compounds into the extracellular medium, conferring resistance. The discovery of natural efflux pump inhibitors is a promising alternative. α-Bisabolol is a sesquiterpene isolated from several plants such as Matricaria chamomilla L. and has important properties such as antibacterial and anti-inflammatory activity. Currently, the formation of inclusion complexes with β-Cyclodextrin has been used for improving the physicochemical characteristics of the host molecule. This study evaluated the effect of α-Bisabolol, in isolation and in complexation with β-Cyclodextrin, as TetK and NorA efflux pump inhibitors in Staphylococcus aureus strains. The minimum inhibitory concentration (MIC) was determined. Subsequently, inhibitory activity over the pumps was observed by an MIC reduction for the antibiotics, by using subinhibitory concentrations (MIC/8) in combination with tetracycline and norfloxacin. The MIC of the compounds was ≥1024 μg/mL. α-Bisabolol potentiated the action of tetracycline and reduced the MIC of norfloxacin to a clinically relevant concentration. The complexed substance showed synergism however, the effect of the isolated α-Bisabolol was superior to the complex. These results indicate α-Bisabolol is a potential substance to be used as an efflux pump inhibitor.

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Análise estrutural de ciclodextrinas: um estudo comparativo entre métodos teóricos clássicos e quânticos

Cited by 28 publications

References 11 publications

Charge sensitivity approach to mutual polarization of reactants: molecular mechanics perspective

Charge sensitivity approach to mutual polarization of reactants: molecular mechanics perspective

Potencialidades e oportunidades na química da sacarose e outros açúcares

Effect of α-Bisabolol and Its β-Cyclodextrin Complex as TetK and NorA Efflux Pump Inhibitors in Staphylococcus aureus Strains

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