Made available in DSpace on 2014-12-17T14:03:32Z (GMT). No. of bitstreams: 1 CinthiaBST.pdf: 1239764 bytes, checksum: b0f986e10d6574ec55e837255b634b41 (MD5) Previous issue date: 2010-02-11 / Coordena??o de Aperfei?oamento de Pessoal de N?vel Superior / The exopolysaccharides are extracellular compounds produced by some species of fungi and bacteria. It is suggested that these molecules, even when in the form of complex polysaccharide-peptide, are the main bioactive molecules of many fungus. Some of the biological activities displayed by these compounds can be accentuated and others may arise when you add chemically polar or nonpolar groups to polysaccharides. The fruiting body of Pleurotus sajor-caju produces a heteropolysaccharide with antineoplastic and antimicrobial activity, but other biological activities of this polymer have not been evaluated. In this work the exopolysaccharide of Pleurotus sajor-caju was sulfated chemically and structurally characterized. We also evaluated the antiproliferative, antioxidant and anticoagulant activities from native exopolysaccharide (PN) and its sulfated derivated (PS). Polyacrylamide gel electrophoresis, infrared spectroscopy and nuclear magnetic resonance (??C) proved successful in sulfation of PN to obtain PS. Analysis by gas chromatography-mass spectroscopy showed that PN and PS are composed of mannose, galactose, 3-O-methyl-galactose and glucose in proportion percentage of 44,9:16,3:19,8:19 and 49, 7:14,4:17,7:18,2, respectively. The percentage of sulfate found in PS was 22.5%. Antioxidants assays revealed that the sulfation procedure affects differently the activities of exopolysaccharides, while the total antioxidant capacity, the scavenging activity of superoxide radical and ferric chelating were not affected by sulfation, on the other hand the chemical modification of PN enhanced the scavenging activity of hydroxyl radical and reducing power. PS also showed anticoagulant activity in a dose-dependent manner and clotting time was 3.0 times higher than the baseline value in APTT at 2 mg/mL. The exopolysaccharide not presented antiproliferative activity against HeLa tumor cells, but PS affects the cellular proliferation in a time-dependent manner. After 72 h, the inhibition rate of PS (2.0 mg/mL) on HeLa cells was about 60%. The results showed that PN sulfation increase some of their activities. / Os exopolissacar?deos s?o compostos extracelulares produzidos por algumas esp?cies de fungos e bact?rias. ? sugerido que estas mol?culas, inclusive quando na forma de complexo polissacar?deo-pept?deo, s?o as principais mol?culas bioativas de v?rios fungos. Muitas das atividades biol?gicas apresentadas por esses compostos podem ser acentuadas e outras podem surgir quando se adiciona quimicamente aos polissacar?deos grupamentos polares ou apolares. O corpo de frutifica??o de Pleurotus sajor-caju produz um heteropolissacar?deo com atividade antioneopl?sica e antimicrobiana, contudo outras atividades biol?gicas desse pol?mero ainda n?o foram avaliadas. Neste trabalho o exopolissacar?deo de Pleurotus sajor-caju foi sulfatado quimicamente e caracterizado estruturalmente. Tamb?m foram avaliadas as atividades antiproliferativa, antioxidante e anticoagulante do exopolissacar?deo nativo (PN) e de seu derivado sulfatado (PS). Eletroforese em gel de agarose, espectroscopia de infravermelho e resson?ncia magn?tica nuclear (??C) comprovaram o sucesso na sulfata??o de PN para a obten??o de PS. An?lise por cromatografia gasosa acoplada a espectroscopia de massa mostrou que PN e PS s?o constitu?dos de manose, galactose, 3-O-metil-galactose e glicose na propor??o percentual de 44,9:16,3:19,8:19 e 49,7:14,4:17,7:18,2, respectivamente. O percentual de sulfato encontrado em PS foi de 22,5%. Testes antioxidantes revelaram que o processo de sulfata??o influencia de forma diferente nas atividades do exopolissacar?deo. Enquanto a capacidade antioxidante total, a capacidade de seq?estro de radical super?xido e a quela??o f?rrica n?o foram influenciadas pela sulfata??o, essa potencializou a atividade seq?estradora de radicais hidroxila e o poder redutor do exopolissacar?deo. Ap?s o processo de sulfata??o o exopolissacar?deo passou a apresentar atividade anticoagulante de forma dose-dependente, triplicando o tempo de coagula??o em rela??o ao controle numa concentra??o de aproximadamente 2 mg/mL. O exopolissacar?deo n?o apresentou atividade antiproliferativa frente ?s c?lulas tumorais HeLa, por?m ap?s sulfata??o ele passou a apresentar essa atividade de forma tempo- ependente, chegando a inibir em 60% a taxa de prolifera??o das c?lulas com 2 mg/mL, ap?s 72 h de exposi??o. Os resultados aqui obtidos mostraram que a sulfata??o do exopolissacar?deo potencializou algumas de suas atividades.