Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 3 de 3
Filtrar
Mais filtros








Base de dados
Intervalo de ano de publicação
1.
Artigo em Inglês | MEDLINE | ID: mdl-35112078

RESUMO

The aim of the present study was to investigate the cytotoxicity induced by an omega-3 derivative, didocosahexaenoin (Dido) on human prostate carcinoma cells and to compare the cytotoxicity to that of docosahexaenoic acid (DHA). Different carcinoma- and non-carcinoma cells were exposed to various concentrations of omega-3 compounds at varying exposure times and the cytotoxicity was measured by MTT assay. The mechanism of Dido-induced apoptosis was investigated in prostate carcinoma cells. Dido induced stronger cytotoxicity than DHA in human prostate carcinoma cells in a dose- and time-dependent manner. Dido was also more selective and potent in inducing cytotoxicity in prostate carcinoma cells than other carcinoma cell lines tested. Pre-treatment with Dido increased the level of reactive oxygen species (ROS) in prostate carcinoma cells. Pre-treatment with various antioxidants reduced the cytotoxicity induced by Dido. Pre-treatment with Dido ≥30 â€‹µM also induced apoptosis which was suggested to involve an externalisation of phosphatidyl serine, a significant increase in the mitochondrial membrane potential (p â€‹< â€‹0.01) and the level of activated caspase 3/7 (p â€‹< â€‹0.05) in prostate carcinoma cells. This study is the first to show that Dido induced cytotoxicity with high selectivity and higher potency than DHA in human prostate carcinoma cells. The mechanism of action is likely to involve an increase in the level of ROS, loss in the mitochondrial membrane potential as well as externalisation of phosphatidyl serine and increase in the caspase 3/7 activity. Dido may have potential to be used for the adjuvant therapy or combination therapy with conventional chemotherapeutic drugs.

2.
Carbohydr Res ; 349: 6-11, 2012 Feb 15.
Artigo em Inglês | MEDLINE | ID: mdl-22197068

RESUMO

In alkaline pulping wood pulp is reacted with concentrated aqueous alkali at elevated temperatures. In addition to producing cellulose for the manufacture of paper, alkaline pulping also generates large amounts of isosaccharinic acids as waste products. Isosaccharinic acids are potentially useful raw materials: they are good metal chelating agents and, in their enantiomerically pure form, they are valuable carbon skeletons with predefined stereochemistry that can be easily functionalised for use in synthesis. Despite this, there is no simple procedure for isolating pure beta-(gluco)isosaccharinic acid and very limited work has been undertaken to determine the chemical and physical properties of this compound. We report here a very simple but effective method for the synthesis of a mixture containing equal portions of the two isosaccharinic acids ((2S,4S)-2,4,5-trihydroxy-2-(hydroxymethyl)pentanoic acid and (2R,4S)-2,4,5-trihydroxy-2-(hydroxymethyl)pentanoic acid) and the separation of the two as their tribenzoate esters. We also report for the first time the aqueous pK(a) of beta-(gluco)isosaccharinic acid (3.61).


Assuntos
Celulose/química , Açúcares Ácidos/síntese química , Açúcares Ácidos/isolamento & purificação , Configuração de Carboidratos , Cristalografia por Raios X , Géis/química , Concentração de Íons de Hidrogênio , Espectroscopia de Ressonância Magnética , Espectrometria de Massas , Modelos Moleculares , Dióxido de Silício/química , Açúcares Ácidos/química , Água/química
3.
Carbohydr Res ; 346(17): 2710-7, 2011 Dec 13.
Artigo em Inglês | MEDLINE | ID: mdl-22000767

RESUMO

The bile adapted strain Bifidobacterium animalis subsp. lactis IPLA-R1 secretes a high molecular weight exopolysaccharide (HMW-EPS) when grown on the surface of agar-MRSC. This EPS is composed of L-rhamnopyranosyl, D-glucopyranosyl, D-galactopyranosyl and D-galactofuranosyl residues in the ratio of 3:1:1:1. Linkage analysis and 1D and 2D NMR spectroscopy were used to show that the EPS has a hexasaccharide repeating unit with the following structure: [See formula in text]. Treatment of the EPS with mild acid cleanly removed the terminal d-galactofuranosyl residue. The eps cluster sequenced for strain IPLA-R1 showed high genetic homology with putative eps clusters annotated in the genomes of strains from the same species. It is of note that several genes coding for rhamnose-precursors are present in the eps cluster, which could be correlated with the high percentage of rhamnose detected in its EPS repeated unit.


Assuntos
Bifidobacterium , Polissacarídeos Bacterianos/química , Configuração de Carboidratos , Sequência de Carboidratos , Hidrólise , Espectroscopia de Ressonância Magnética , Dados de Sequência Molecular , Peso Molecular
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA