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The abstract should be a single paragraph which summarises the content of the article. This study utilizes density functional theory (DFT) calculations to explore the energetic and magnetic stability of neutral and charged potassium (K) clusters doped with yttrium (Y). We aim to elucidate the influence of Y doping on the energetics and structures of these clusters, comparing them to undoped K clusters. Ground states of 64 polyhedral structures, all of them encapsulating at least one Y atom, were obtained. Y doping generally increased the spin magnetic moment, with charged clusters exhibiting the highest values. Notably, the K12Y+ cluster, possessing an icosahedral geometry and a magnetic moment of 6µB, is classified as a magnetic superatom. Additionally, we identified 14 superatoms with high magnetic robustness. The density of states (DOS) and spin density calculations additionally highlighted the substantial role played by yttrium in the electronic density of the electrons responsible for inducing magnetism in these clusters.
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Among the biological targets extensively investigated to improve inflammation and chronic inflammatory conditions, cyclooxygenase enzymes (COXs) occupy a prominent position. The inhibition of these enzymes, essential for mitigating inflammatory processes, is chiefly achieved through Non-Steroidal Anti-Inflammatory Drugs (NSAIDs). In this work, we introduce a novel method-based on computational molecular docking-that could aid in the structure-based design of new compounds or the description of the anti-inflammatory activity of already-tested compounds. For this, we used eight crystal complexes (four COX-1 and COX-2 each), and each pair had a specific NSAID: Celecoxib, Meloxicam, Ibuprofen, and Indomethacin. This selection was based on the ligand selectivity towards COX-1 or COX-2 and their binding mode. An interaction profile of each NSAID was compiled to detect the residues that are key for their binding mode, highlighting the interaction made by the Me group. Furthermore, we rigorously validated our models based on structural accuracy (RMSD < 1) and (R2 > 70) using eight NSAIDs and thirteen compounds with IC50 values for each enzyme. Therefore, this model can be used for the binding mode prediction of small and structurally rigid compounds that work as COX inhibitors or the prediction of new compounds that are designed by means of a structure-based approach.
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DFT calculations were performed to study the effect on energetic and magnetic stability when clusters with up to 24 lithium atoms were doped with one and two atoms of yttrium. In this, the effect of the charge was considered. As a result, some stable structures were identified as possible magnetic superatoms, among them, the YLi12+ cluster with an icosahedron geometry with a spin magnetic moment of 4 bohr magnetons. The participation of yttrium in the electron density of the unpaired electrons providing magnetism in clusters was corroborated at the level of a density of states (DOS) calculation and a spin density calculation. In particular, in the Y2Li12+ superatom, it was found that the encapsulated yttrium atom participates with 35.02% and the second yttrium atom with 15.04%. These percentages, with a contribution from p orbitals, but to a greater extent by d orbitals. The complementation to these percentages is due to the participation of the s and p orbitals of the lithium atoms. In general, doping with a second yttrium atom allowed to obtain a greater amount of high magnetic moments, and considering charged clusters allowed to obtain also high magnetic moments.
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Cytotoxic effects of cannabidiol (CBD) and tamoxifen (TAM) have been observed in several cancer types. We have recently shown that CBD primarily targets mitochondria, inducing a stable mitochondrial permeability transition pore (mPTP) and, consequently, the death of acute lymphoblastic leukemia (T-ALL) cells. Mitochondria have also been documented among cellular targets for the TAM action. In the present study we have demonstrated a synergistic cytotoxic effect of TAM and CBD against T-ALL cells. By measuring the mitochondrial membrane potential (ΔΨm), mitochondrial calcium ([Ca2+]m) and protein-ligand docking analysis we determined that TAM targets cyclophilin D (CypD) to inhibit mPTP formation. This results in a sustained [Ca2+]m overload upon the consequent CBD administration. Thus, TAM acting on CypD sensitizes T-ALL to mitocans such as CBD by altering the mitochondrial Ca2+ homeostasis.
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Cálcio/metabolismo , Canabidiol/farmacologia , Peptidil-Prolil Isomerase F/metabolismo , Leucemia-Linfoma Linfoblástico de Células Precursoras/metabolismo , Tamoxifeno/farmacologia , Linhagem Celular Tumoral , Peptidil-Prolil Isomerase F/química , Sinergismo Farmacológico , Homeostase/efeitos dos fármacos , Humanos , Células Jurkat , Potencial da Membrana Mitocondrial/efeitos dos fármacos , Poro de Transição de Permeabilidade Mitocondrial/metabolismo , Modelos Moleculares , Simulação de Acoplamento Molecular , Leucemia-Linfoma Linfoblástico de Células Precursoras/tratamento farmacológico , Conformação ProteicaRESUMO
With the idea of proposing solid state systems that have a high storage capacity of molecular hydrogen, a density functional theory study of magnesium oxide (MgO)n clusters (n = 1-10) was carried out. Hydrogen-magnesium oxide systems presented adsorption energy values in accordance with the previously reported studies of physisorption processes; additionally negative values of ΔGads were found describing adsorption as a favorable process. Here, the (MgO)7 cluster presented the highest adsorption energy. The storage capacity by weight of the magnesium oxide clusters was greater than the recommended percentage (7.5%) by the U.S. Department of Energy. QTAIM analysis and non-covalent index plots highlighted the weak nature of the interaction between the MgO clusters and hydrogen molecules, and the fundamental role of the Mg-O bonds' polarity in the systems' storage capacity.
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Annona purpurea, known in Mexico as "cabeza de negro" or "ilama", belongs to the Annonaceae family. Its roots are employed in folk medicine in several regions of Mexico. Taking that information into account, a chemical and biological analysis of the components present in the roots of this species was proposed. Our results demonstrated that the dichloromethane (DCM) extract was exclusively constituted by a mixture of five new acetogenins named annopurpuricins A-E (1-5). These compounds have an aliphatic chain of 37 carbons with a terminal α,ß unsaturated γ-lactone. Compounds 1 and 2 belong to the adjacent bis-THF (tetrahydrofuran) α-monohydroxylated type, while compounds 3 and 4 belong to the adjacent bis-THF α,α'-dihydroxylated type; only compound 5 possesses a bis-epoxide system. Complete structure analysis was carried out by spectroscopy and chemical methods. All compounds were evaluated for their antiproliferative activity on three human tumor cell lines (MSTO-211H, HeLa and HepG2). Compounds 1-4 inhibited significantly the growth of HeLa and HepG2 cells, showing GI50 values in the low/subnanomolar range, while 5 was completely ineffective under the tested conditions. The investigation of the mechanism of action responsible for cytotoxicity revealed for the most interesting compound 1 the ability to block the complex I activity on isolated rat liver mitochondria (RLM).
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Acetogeninas/química , Annona/química , Raízes de Plantas/química , Acetogeninas/isolamento & purificação , Acetogeninas/farmacologia , Animais , Annona/metabolismo , Linhagem Celular Tumoral , Proliferação de Células/efeitos dos fármacos , Humanos , Espectroscopia de Ressonância Magnética , Potencial da Membrana Mitocondrial/efeitos dos fármacos , Mitocôndrias Hepáticas/efeitos dos fármacos , Mitocôndrias Hepáticas/metabolismo , Conformação Molecular , Raízes de Plantas/metabolismo , RatosRESUMO
There are many chronic diseases related with inflammation. The chronic inflammation can produce other problems as cancer. Therefore, it is necessary to design drugs with better anti-inflammatory activity than those in the clinic. Likewise, these could be used in chronic treatments with minimum adverse effects. The amide or ester functionality in combination with the insertion of a silyl alkyl moiety is able to improve some drug properties. In this context, the evaluation of a group of silicon containing ibuprofen derivatives (SCIDs) as antioxidants and anti-inflammatory agents is reported. Antioxidant activity was evaluated by the 2,2-Diphenyl-1-picrylhydrazyl (DPPH⨪), 2,2'-Azino-bis(3-ethylbenzothiazoline-6-sulfonic) acid (ABTSâ¢+) and the Fe(II) chelating ability methods. The anti-inflammatory activity was determined by using the carrageenan induced rat paw edema. The gastrotoxic profile of the SCIDs that displayed significant anti-inflammatory activity was determined by the indomethacin induced ulceration method. The SCIDs performed better than ibuprofen as chelating agents for Fe(II) and as scavengers for the free radicals DPPH⢠and ABTSâ¢+. On the anti-inflammatory test, compound 4a inhibited the edema up to 87%, while 4d &10b achieved significant inflammation inhibition at a lower effective dose 50 (ED50) than ibuprofen´s. None of the SCIDs endowed with anti-inflammatory activity, showed significant gastrotoxic effects with respect to those displayed by ibuprofen. Based on the experimental results and aided by the theoretical docking approach, it was possible to rationalize how the SCIDs may bind to cyclooxygenase isoforms and helped to explain their reduced gastrotoxicity. The evaluated effects were improved in SCIDs with respect to ibuprofen.
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Simulação por Computador , Ibuprofeno/química , Ibuprofeno/farmacologia , Silício/química , Animais , Anti-Inflamatórios/química , Anti-Inflamatórios/metabolismo , Anti-Inflamatórios/farmacologia , Antioxidantes/química , Antioxidantes/metabolismo , Antioxidantes/farmacologia , Benzotiazóis/química , Compostos de Bifenilo/química , Domínio Catalítico , Ciclo-Oxigenase 2/química , Ciclo-Oxigenase 2/metabolismo , Ibuprofeno/metabolismo , Quelantes de Ferro/química , Quelantes de Ferro/metabolismo , Quelantes de Ferro/farmacologia , Masculino , Simulação de Acoplamento Molecular , Picratos/química , Ratos , Ratos Wistar , Ácidos Sulfônicos/químicaRESUMO
The in vitro antioxidant activities of eight 3-carboxycoumarin derivatives were assayed by the quantitative 1,1-diphenyl-2-picrylhydrazil (DPPHâ¢) radical scavenging activity method. 3-Acetyl-6-hydroxy-2H-1-benzopyran-2-one (C1) and ethyl 6-hydroxy-2-oxo-2H-1-benzopyran-3-carboxylate (C2) presented the best radical-scavenging activity. A quantitative structure-activity relationship (QSAR) study was performed and correlated with the experimental DPPH⢠scavenging data. We used structural, geometrical, topological and quantum-chemical descriptors selected with Genetic Algorithms in order to determine which of these parameters are responsible of the observed DPPH⢠radical scavenging activity. We constructed a back propagation neural network with the hydrophilic factor (Hy) descriptor to generate an adequate architecture of neurons for the system description. The mathematical model showed a multiple determination coefficient of 0.9196 and a root mean squared error of 0.0851. Our results shows that the presence of hydroxyl groups on the ring structure of 3-carboxy-coumarins are correlated with the observed DPPH⢠radical scavenging activity effects.
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Cumarínicos/farmacologia , Sequestradores de Radicais Livres/síntese química , Sequestradores de Radicais Livres/farmacologia , Algoritmos , Benzopiranos/síntese química , Benzopiranos/farmacologia , Compostos de Bifenilo/química , Biologia Computacional , Cumarínicos/síntese química , Cumarínicos/química , Modelos Teóricos , Picratos/química , Relação Quantitativa Estrutura-AtividadeRESUMO
INTRODUCTION: Renin is the main rate-limiting enzyme in the renin-angiotensin-aldosterone system. Its gene, REN, is a candidate crucial factor in essential hypertension and cardiovascular disease. The aim of this study was to evaluate allele and haplotype distributions of REN polymorphisms, and to estimate normalised linkage disequilibrium (D') in Mexican and German populations. MATERIALS AND METHODS: Four groups were studied for the REN single nucleotide polymorphisms (SNPs) 1205C>T, 1303G>A, and 10607G>A, in population samples of Mexican Mestizo (n = 86), Mexican Huichol (n = 49), German (n = 39), and individuals with hypertension diagnosis (n = 66). Polymorphisms were detected by PCR-RFLP. Genotype, allele and haplotype frequencies were estimated. RESULTS: SNP 1205C>T and 10607G>A allele and genotype distribution showed inter-group differences. The 1205T and 10607A allele showed a significance difference in hypertensive population. Haplotype analysis also showed some inter-group differences, especially in 1205C-1303G-10607G, 1205C-1303G-10607A and 1205T-1303G-10607G haplotypes. The segregation analysis disclosed complete linkage disequilibrium between 1205 and 1303 loci. CONCLUSION: These results provide an example of genetic diversity in related populations and illustrate the convenience of increasing the number of loci in associative studies between diseases and candidate genes.
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Variação Genética , Haplótipos/genética , Desequilíbrio de Ligação/genética , Renina/genética , Sequência de Bases , Eletroforese em Gel de Ágar , Etnicidade/genética , Frequência do Gene/genética , Alemanha , Humanos , Funções Verossimilhança , México , Dados de Sequência Molecular , Polimorfismo de Nucleotídeo Único/genéticaRESUMO
Nineteen 2-[(R-phenyl)amine]-1,4-naphthalendione derivatives (PAN) were tested on spinach thylakoids for their activity as electron acceptors. These molecules act as photosystem I electron acceptors in the micromolar range. AC(50) values varied from 5 nM to 24 microM. QSAR analysis revealed a linear correlation of the m-PAN derivative log [1/AC(50)] with the energy difference of the LUMO and HOMO orbitals. The biological activity of p-PAN derivatives correlates linearly with structural parameters. Electron affinity is being the most important. The half wave I potential values (E(1/2)) of PAN compounds (from -213 to -569 mV vs. NHE) match with the mid-point potentials of the A(0) to F(X) niche of PSI electron transport carriers. The logP values of PAN derivatives were 3.35 and 3.88, indicating that they are hydrophobic compounds. Therefore PAN compounds accept electrons at the hydrophobic A(0) to F(X) niche of PSI.