Navegando por Palavras-chave "Antifungal"
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- ItemSomente MetadadadosBiophysical and biological properties of small linear peptides derived from crotamine, a cationic antimicrobial/antitumoral toxin with cell penetrating and cargo delivery abilities(Elsevier Science Bv, 2017) Dal Mas, C. [UNIFESP]; Pinheiro, D. A. [UNIFESP]; Campeiro, J. D. [UNIFESP]; Mattei, B. [UNIFESP]; Oliveira, V. [UNIFESP]; Oliveira, E. B.; Miranda, A. [UNIFESP]; Perez, K. R. [UNIFESP]; Hayashi, M. A. F. [UNIFESP]Crotamine is a natural polypeptide from snake venom which delivers nucleic acid molecules into cells, besides having pronounced affinity for negatively charged membranes and antifungal activity. We previously demonstrated that crotamine derived short linear peptides were not very effective as antifungal, although the non structured recombinant crotamine was overridingly more potent compared to the native structured crotamine. Aiming to identify the features necessary for the antifungal activity of crotamine, two linear short peptides, each comprising half of the total positively charged amino acid residues of the full-length crotamine were evaluated here to show that these linear peptides keep the ability to interact with lipid membrane model systems with different phospholipid compositions, even after forming complexes with DNA. Interestingly, the presence of cysteine residues in the structure of these linear peptides highly influenced the antifungal activity, which was not associated to the lipid membrane lytic activity. In addition to the importance of the positive charges, the crucial role of cysteine residues was noticed for these linear analogs of crotamine, although the tridimensional structure and lipid membrane lytic activity observed only for native crotamine was not essential for the antifungal activity. As these peptides still keep the ability to form complexes with DNA molecules with no prejudice to their ability to bind to lipid membranes, they may be potentially advantageous as membrane translocation vector, as they do not show lipid membrane lytic activity and may harbor or not antifungal activity, by keeping or not the semi-essential amino acid cysteine in their sequence.
- ItemAcesso aberto (Open Access)Embalagem ativa antifúngica para aumentar a vida útil do pão de forma fatiado(Universidade Federal de São Paulo, 2024-08-19) Ferreira, Julia Guirão [UNIFESP]; Venturini, Anna Cecilia [UNIFESP]; http://lattes.cnpq.br/8531229038363609; http://lattes.cnpq.br/8531229038363609; http://lattes.cnpq.br/0326859716766985A busca do consumidor por alimentos com apelo à sustentabilidade e ao bem-estar tem impulsionado as indústrias de panificação na diversificação de produtos integrais, com a introdução de grãos e farinhas especiais. O pão é um alimento fundamental consumido em todo o mundo, mas frequentemente passa por alterações físico-químicas e microbiológicas que afetam sua qualidade e vida útil. A deterioração microbiológica, que leva a um crescimento visível de mofo e à possível produção de micotoxinas, é um problema comum. Para lidar com esses desafios, a indústria de panificação tem explorado vários tratamentos para melhorar a segurança do pão e estender sua vida útil. O principal objetivo deste projeto foi desenvolver uma bandeja celulósica revestida com filme antifúngico à base de quitosana, incorporado com óleo essencial de capim-limão, para compor o sistema de embalagem para pão de forma fatiado. Análises físico-químicas e mecânicas do sistema ativo filme-papel- cartão foram realizadas para sua caracterização: homogeneidade de revestimento; gramatura; espessura; permeabilidade à gordura; análises térmicas e teste Cobb. Os resultados mostraram diferenças significativas nas amostras com revestimento, para homogeneidade e permeabilidade à gordura. A homogeneidade do papel contendo revestimento com óleo essencial foi muito eficiente, além de produzir um efeito de barreira para a solução colorida. Além, disso, o revestimento contendo o óleo, também apresentou barreira à gordura. Muitos resultados tiveram uma variação muito equena, o que pode estar relacionado com a quantidade de solução e de camadas utilizadas no revestimento. A análise de concentração inibitória mínima para os fungos P. roqueforti PR11 e P. paneum LMQA05 mostraram resultados positivos. A concentração inibitória mínima de ambos os microrganismos foi de 0,125 mg/mL e a concentração fungicida foi de 0,50 mg/mL, menores que a concentração utilizada na camada de revestimento (20 mg/mL). O sistema de embalagem ativo proposto neste trabalho pode ser uma alternativa promissora para a substituição de conservantes sintéticos (ácido propiônico, ácido sórbico e seus sais), conhecidos como “antimofo” utilizados para retardar a deterioração fúngica em pães de forma industrializados, além de explorar o potencial da reutilização de resíduos industriais e incentivar o mercado sustentável. Testes adicionais devem ser realizados a fim de determinar a concentração ótima de óleo essencial no revestimento das bandejas celulósicas, capaz de estender a vida útil do pão fatiado sem afetar negativamente a avaliação organoléptica do produto.
- ItemAcesso aberto (Open Access)Estudos da relação estrutura-atividade da Rondonina e análogos(Universidade Federal de São Paulo, 2022-04-27) Rocha, Ana Laís Bignotto da [UNIFESP]; Oliveira Junior, Vani Xavier de; Silva Junior, Pedro Ismael da; http://lattes.cnpq.br/7158586957386749; http://lattes.cnpq.br/8202238208943023; http://lattes.cnpq.br/7431823973508374Introduction: Rondonin is a native AMP, isolated from the spider Acanthoscurria rondoniae's plasm , presenting a molecular mass of 1236,78 Da (UniProt acession number B3EWP8), features antifungal activity, on plasmatic membrane inside targets, and tends not to structure itself. Objectives: The studies tried to stabilish the relation between the structure and activity of the synthesized analogs from native Rondonin. Peptides were projected from the studie of N and C terminus modification, charge increment – trough single arginine substitutions - (Arg-scan) -, and double, besides tryptophan punctual substitution and glycine deletion. These changes, in the molecular design, were elaborated with the goal of studying possible improvement in antimicrobial, antifungal; antisporulatory;hemolytic; spores germination influence and stability to enzymatic degradation. Methods: Analogues were synthesized in solid phase synthesis strategy trough High Performance Liquid Chromatography.and characterized through Mass Spectrometry (LC/ESI-MS). Antimicrobial, antisporulatory, antifungal and antigermintaive studies were determined through growth inhibition assay, in liquid medium conformational study was realized with Circular Dichroism (CD) spectrometry in four mediums. Results: From the information that Rondonin acts in internal targets was possible to develop molecules with sequential arginine substitutions, which may generate a charge increment added to the amphipaticity of designed analogues. This simple premise was established with the goal to build molecules with greater capacity of interaction with negatively charged targets, such as ribosomes, Golgi apparatus mitochondria DNA and RNAs. Secondary structures show tendency to randomize. Peptides do not show hemolysis in inhibitory concentrations. Stability times of studied peptides were compatible with stability of commercial composts with oral pathway administration, in concentrastions without toxicity, the molecule with greater stability was analogue 8. Synthesis of developed analogues, that has arginine substitutions in the hydrophobic central moiety, showed improvement the antifungal activity, that suggests that charge increase and amphipaticity alteration were very important for analogues activities, the molecule with the best antifungal activity was analogue analogue 10. However, analogues did not show activities against Gram-positive and Gram-negative bacteria under the tested concentrations. Nevertheless sporulation assays realized with filamentous fungus showed important inhibition activities of conidia formation. The same activity was not found on the 8 pharmaceutics tested for comparative ends. The peptides that showed better antisporulatory MIC values against Penicilium expansum – Bread isolated was analogue 10 at 0,7µmol.L-1 concentration. Antigerminative activities were obtained from mature spores of P. expansum in rich medium (NaCl 45 g.L-1) and poor medium (distilled water) analogue 2, analogue 9 and analogue 18 showed concentration of antigermination 28 µmol.L-1 much smaller than the control made through Hydrogen peroxide 15 g.L-1. Conclusion: Structural modifications from linear Rondonin analogues sequence changes were fundamental for increased antifungal activity, against filamentous fungi and several species of Candida genus. Besides sporulation assays, in filamentous fungi, showed new possibilities for research development about fungal life cycle analysis reinforcing the utility of AMPs as molecular engineering tools. The design based in a simple premise of analogues production developed a spectrum of peptides with multiple and potent activities. These results provide information about the structure activity relationship for the design of new analogues with antifungal activitiy.
- ItemSomente MetadadadosIn vitro antifungal efficacy of copper nanoparticles against selected crop pathogenic fungi(Elsevier B.V., 2014-01-15) Kanhed, Prachi; Birla, Sonal; Gaikwad, Swapnil; Gade, Aniket; Seabra, Amedea B. [UNIFESP]; Rubilar, Olga; Duran, Nelson; Rai, Mahendra; SGB Amravati Univ; Universidade Federal de São Paulo (UNIFESP); Univ La Frontera; Universidade Estadual de Campinas (UNICAMP)Copper nanoparticles play an important role in the field of optics and electronics, and also as a novel antimicrobial. in the present study, we report antifungal activity of copper nanoparticles against selected crop pathogenic fungi. Copper nanoparticles were synthesized by chemical reduction of Cu2+ in the presence of Cetyl Trimethyl Ammonium Bromide and isopropyl alcohol. Characterizations of copper nanoparticles were carried out by UV-visible spectroscopy, nanoparticles tracking analysis (NTA), Fourier transform infrared spectroscopy (FTIR) and transmission electron microscopy (TEM) which revealed that synthesized nanoparticles were coated by Cetyl Trimethylammonium Bromide (CTAB) having particle size of 3-10 nm. Copper nanoparticles demonstrated significant antifungal activity against plant pathogenic fungi: Phoma destructive (DBT-66), Curvularia lunata (MTCC no. 2030), Alternaria alternate (MTCC No. 6572) and Fusarium oxysporum (MTCC No. 1755). Since for the synthesis of copper nanoparticles the present chemical method by using C-TAB-IPA is found to be simple, economic and fast, the synthesized copper nanoparticles can be used as a novel antifungal agent in agriculture to control the plant pathogenic fungi as well as potent disinfectant in poultry and animal husbandry. (C) 2013 Elsevier B.V. All rights reserved.