15 research outputs found
Partial characterization and anticoagulant activity of a heterofucan from the brown seaweed Padina gymnospora
The brown algae Padina gymnospora contain different fucans. Powdered algae were submitted to proteolysis with the proteolytic enzyme maxataze. The first extract of the algae was constituted of polysaccharides contaminated with lipids, phenols, etc. Fractionation of the fucans with increasing concentrations of acetone produced fractions with different proportions of fucose, xylose, uronic acid, galactose, and sulfate. One of the fractions, precipitated with 50% acetone (v/v), contained an 18-kDa heterofucan (PF1), which was further purified by gel-permeation chromatography on Sephadex G-75 using 0.2 M acetic acid as eluent and characterized by agarose gel electrophoresis in 0.05 M 1,3 diaminopropane/acetate buffer at pH 9.0, methylation and nuclear magnetic resonance spectroscopy. Structural analysis indicates that this fucan has a central core consisting mainly of 3-Ă-D-glucuronic acid 1-> or 4-Ă-D-glucuronic acid 1 ->, substituted at C-2 with alpha-L-fucose or Ă-D-xylose. Sulfate groups were only detected at C-3 of 4-alpha-L-fucose 1-> units. The anticoagulant activity of the PF1 (only 2.5-fold lesser than low molecular weight heparin) estimated by activated partial thromboplastin time was completely abolished upon desulfation by solvolysis in dimethyl sulfoxide, indicating that 3-O-sulfation at C-3 of 4-alpha-L-fucose 1-> units is responsible for the anticoagulant activity of the polymer.Universidade Federal do Rio Grande do Norte Departamento de BioquĂmica LaboratĂłrio de GlicobiologiaUniversidade Federal do Rio Grande do Norte Departamento de BioquĂmica LaboratĂłrio de Biotecnologia de PolĂmeros NaturaisUniversidade Federal de SĂŁo Paulo (UNIFESP) Escola Paulista de Medicina Departamento de BioquĂmicaUNIFESP, EPM, Depto. de BioquĂmicaSciEL
Estudo do potencial antimicrobiano e citotóxico da espécie Pouteria venosa (Sapotaceae)
Partial characterization and anticoagulant activity of a heterofucan from the brown seaweed Padina gymnospora
Dna Damage In Peripheral Blood Lymphocytes And Association With Polymorphisms In The Promoter Region Of The Cyp2e1 Gene In Alcoholics From Central Brazil
DNA damage caused by the accumulation of bio-products generated in the biotransformation of ethanol to acetaldehyde mediated by the CYP2E1 enzyme has been studied. To evaluate DNA damage in peripheral blood lymphocytes and the possible association with polymorphisms in the promoter region of the CYP2E1 gene, we performed a case-control study including 75 alcoholics and 59 individuals who consume alcohol socially. Alcoholics were previously diagnosed by the Psychosocial Care Center â Alcohol and Drugs (CAPS A/D) in the city of Goiania, Goias state, Central Brazil. DNA damage was evaluated by comet assay. The analysis of the rs3813867, rs2031920, and rs2031921 polymorphisms in the promoter region of CYP2E1 gene was performed by Sanger sequencing. Men older than 35 years old were the most common alcoholics. We found increased DNA damage in the case group, compared to the control group (p < 0.001). Alcoholics who were heterozygous in the rs3813867, rs2031920, and rs2031921 polymorphisms showed higher DNA damage (tail length and olive tail moment), compared to individuals with the homozygous non-mutated allele. Previous studies have shown that polymorphisms in the promoter region of the CYP2E1 gene could cause higher CYP2E1 transcriptional activity, increasing enzyme activity compared with nondrinkers, indicating that the presence of the mutated allele (heterozygous or homozygous) may be associated with higher alcohol metabolic rates and therefore show increased acetaldehyde levels after alcohol consumption, which then can exert its carcinogenic effect. © 2016 Elsevier Inc.573539201210267001217, FAPEG, Fundação de Amparo Ă Pesquisa do Estado de GoiĂĄ