Analysis of two drying methods on the yield and activity of sulphated polysaccharides extracted from Halymenia sp. /Analise de dois metodos de secagem sobre o rendimento e atividade de polissacarideos sulfatados extraidos da rodoficea Halymenia sp

Sulfated polysaccharides (SPs) have attracted growing interest for various biotechnological applications. We evaluated the efficiency of two methods of drying SPs (M I and II) extracted from Halymenia sp Rhodophyceae in order to compare the yield, purification and anticoagulant activity. The total SPs (TSPs) were first extracted with papain in 100 mM sodium acetate (pH 5.0) containing cysteine and EDTA (5 mM). The TSPs obtained were dried in an oven (M I) or lyophilized (M II) and then examined by ion exchange chromatography (DEAE-cellulose) using the NaCl gradient technique. The fractions were analyzed by 0.5% agarose gel electrophoresis and the in vitro anticoagulant activity was evaluated by the activated partial thromboplastin time test using normal human plasma and compared to heparin (HEP) (193.00 IU [mg.sup.-1]). There was a difference in TSP yield of 19.05% and similar chromatographic SP profiles. Electrophoresis revealed fractions with distinct resolutions. The fractions eluted with 0.75 M of salt (M I and II) were the most active, measuring 27.40 and 72.66 IU [mg.sup.-1], respectively, when compared to HEP. Therefore, obtaining SP with anticoagulant activity from Halymenia sp. is more efficient by freeze-drying. Keywords: Halymeniales, sulfated macromolecules, drying methods, blood coagulation. Os polissacarideos sulfatados (PS) tem despertado interesse crescente para diversas aplicacoes em biotecnologia. Avaliou-se a eficiencia de duas metodologias de secagem de PSs (M I e II) extraidos da rodoficea Halymenia sp. a fim de se comparar o rendimento, a purificacao e a atividade anticoagulante. Inicialmente, os PS totais (PSTs) foram extraidos com papaina em tampao acetato de sodio 100 mM (pH 5,0) contendo cisteina e EDTA (5 mM). Os PSTs foram secados em estufa (M I) ou liofilizados (M II), seguido por cromatografia de troca ionica (DEAE-celulose) utilizando um gradiente de NaCl. As fracoes foram analisadas por eletroforese em gel de agarose a 0,5% e a atividade anticoagulante "in vitro" avaliada por meio do teste do tempo de tromboplastina parcial ativada usando plasma humano normal e comparadas a heparina (HEP) (193.00 UI [mg.sup.-1]). Verificaram-se diferenca no rendimento de PSTs (19,05%) e semelhantes perfis cromatograficos de PS, revelando, por eletroforese, fracoes de PS distintas em grau de resolucao entre os metodos. As fracoes eluidas com 0,75 M de sal (M I e II) foram as mais ativas, com valores de atividade da ordem de 27,40 e 72,66 UI [