Navegando por Palavras-chave "BODIPY"

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    Antioxidant, anti-acetylcholinesterase and cytotoxic activities of ethanol extracts of peel, pulp and seeds of exotic Brazilian fruits Antioxidant, anti-acetylcholinesterase and cytotoxic activities in fruits
    (Elsevier B.V., 2012-11-01) Omena, Cristhiane Maria Bazilio; Valentim, Iara Barros; Guedes, Glaucevane da Silva; Rabelo, Luiza Antas; Mano, Camila Marinho; Etelvino, José Henriques Bechara, [UNIFESP]; Sawaya, Alexandra Christine Helena Frankland; Trevisan, Maria Teresa Salles; Costa, Joao Gomes da; Ferreira, Roberta Costa Silva; Sant'Ana, Antonio Euzebio Goulart; Goulart, Marilia Oliveira Fonseca; Univ Fed Alagoas; Univ Pernambuco; Universidade de São Paulo (USP); Universidade Federal de São Paulo (UNIFESP); Universidade Estadual de Campinas (UNICAMP); Univ Fed Ceara; Empresa Brasileira de Pesquisa Agropecuária (EMBRAPA)
    Ethanol extracts of powdered genipap (Genipa americana L), umbu (Spondia tuberosa A.) and siriguela (Spondia purpurea L) prepared from separate pulp, seeds and peel were investigated for their (i) antioxidant capacity, which was evaluated by various known methods; (ii) acetylcholinesterase (AChE) inhibitory activity; and (iii) cytotoxic effect on corneal epithelial cells of sheep. the highest values of total phenolic content were obtained with peel and seed extracts. Siriguela and umbu (seeds and peel) extracts displayed the highest antioxidant activities. Lipid peroxidation assays using mimetic biomembranes and mouse liver homogenates indicated that genipap pulp is a promising antioxidant. the investigation of phenols and organic acid contents revealed the presence of quercetin, citric and quinic acids, chlorogenic acid derivatives, among others, in several extracts, with the highest amount found in siriguela seeds. Genipap pulp and siriguela seed ethanol extracts presented an AChE inhibition zone similar to that of the positive control, carbachol. AChE inhibition assay with chlorogenic acid, one of the main constituents of siriguela seeds, revealed that this acid showed activity similar to that of the control physostigmine. These data suggest that these extracts are potentially important antioxidant supplements for the everyday human diet, pharmaceutical and cosmetic industries. (C) 2012 Elsevier B.V. All rights reserved.
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    Potential energy surface of excited semiconductors: Graphene quantum dot and BODIPY
    (Elsevier Science Bv, 2016) Colherinhas, Guilherme; Fileti, Eudes Eterno [UNIFESP]; Chaban, Vitaly V. [UNIFESP]
    Binding energy (BE) is an important descriptor in chemistry, which determines thermodynamics and phase behavior of a given substance. BE between two molecules is not directly accessible from the experiment. It has to be reconstructed from cohesive energies, vaporization heats, etc. We report BE for the excited states of two semiconductor molecules - boron-dipyrromethene (BODIPY) and graphene quantum dot (GQD) - with water. We show, for the first time, that excitation increases BE twofold at an optimal separation (energy minimum position), whereas higher separations lead to higher differences. Interestingly, the effects of excitation are similar irrespective of the dominant binding interactions (van der Waals or electrostatic) in the complex. This new knowledge is important for simulations of the excited semiconductors by simplified interaction functions. (C) 2016 Elsevier B.V. All rights reserved.
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    Total phenolic content and free radical scavenging activities of methanolic extract powders of tropical fruit residues
    (Elsevier B.V., 2009-07-15) Oliveira, Alane Cabral de; Valentim, Iara Barros; Silva, Cicero Alexandre; Bechara, Etelvino Jose Henriques [UNIFESP]; Barros, Marcelo Paes de; Mano, Camila Marinho [UNIFESP]; Goulart, Marilia Oliveira Fonseca; Univ Fed Alagoas; Universidade de São Paulo (USP); Universidade Federal de São Paulo (UNIFESP); Univ Cruzeiro Sul
    Methanolic extract powders of acerola, passion fruit and pineapple industrial residues, including pulp, seeds and peel, altogether (except for acerola) devoid of seeds, were screened for antioxidant capacity. the total phenolic contents (TPCs) of the extract powders were compared with their radical-scavenging activities (RSA) against both DPPH(center dot) and superoxide anion (O(2)(center dot-)) radicals, and their protective effect against liposome peroxidation, triggered by peroxyl radical. Lipid peroxidation was followed by the fluorescence decay of the probe, 4,4-difluoro-5-(4-phenyl-1,3-butadienyl)-4-bora-3a,4a-diaza-s-indacene-3-undecanoic acid (C(11)-BODIPY(581/591)). the TPCs of acerola, passion fruit and pineapple extract powders were (94.6 +/- 7.4); (41.2 +/- 4.2) and (9.1 +/- 1.3) mg of gallic acid equivalents g(-1) of dry extract, respectively. Acerola showed the best RSA-DPPH(center dot) scores, whereas passion fruit was more protective on the RSA-O(2)(center dot-) system. Together with the protective effects against lipid peroxidation (rate of BODIPY decay) which, were similar for acerola and passion fruit extracts, these data suggest that the methanolic extracts of acerola and passion fruit residues may be useful as antioxidant supplements, particularly the acerola extract, due to its high phenolic content. (C) 2008 Elsevier B.V. All rights reserved