Analysis of two precipitation methods on the yield, structural features and activity of sulfated polysaccharides from Gracilaria cornea (Rhodophyta)

The global demand for natural products from seaweeds has increased worldwide; however, no description of the use of isoamly alcohol (IAA) for obtaining of sulfated polysaccharides (SPs) has been reported. We investigated the efficiency of two precipitation methods (M) in obtaining SPs from the red seaweed Gracilaria cornea. SPs enzymatically isolated were concentrated with cetylpyridinium chloride (M I) or IAA (M II) and extracts were examined with regard to their yield, structural features and in vitro effects on the activated partial thromboplastin time (APTT) using normal human plasma and standard heparin (193 IU [mg.sup.-1]). Yield difference reached 12.99%. Quantitative determination of sulfate was similar between the two methods (26%), but extracts revealed different pattern on charge density by agarose gel electrophoresis. Whereas both extracts revealed as agarocolloids, alternative M II was also efficient for lipids, proteins and nucleic acids according to the infrared analysis. Extracts had virtually no effect on APPT (1.95 and 2 IU [mg.sup.-1] for M I and M II, respectively). The results revealed IAA as an alternative solvent for obtaining SPs from the red seaweed G. cornea, depending on the industry' usage criterion. Keywords: Rhodophyceae, polysulfated, precipitation methods, structural analysis, APTT test. A demanda global de produtos naturais de algas marinhas tem aumentado mundialmente. Entretanto, a obtencao de polissacarideos sulfatados (PSs) com alcool isoamilico (AIA) nao e relatada. Investigou-se a eficiencia de dois metodos (M) de precipitacao de PSs da alga marinha vermelha Gracilaria cornea. Os PSs isolados enzimaticamente foram concentrados com cloreto cetilpiridiminio (M I) ou AIA (M II). Os extratos foram examinados, segundo seu rendimento, caracteristicas estruturais e efeitos in vitro sobre o tempo de tromboplastina parcial ativada (TTPA) usando plasma humano normal e heparina padrao (193 UI [mg.sup.-1]). A diferenca nos rendimentos foi 12,99% e semelhante determinacao quantitativa de sulfato foi obtida entre os metodos (26%). A eletroforese em gel de agarose revelou diferencas em termos de densidade de cargas entre os extratos. Enquanto ambos os extratos revelaram agarocoloides, o metodo M II tambem se mostrou alternativo para lipidios, proteinas e acidos nucleicos de acordo com a analise de infravermelho. Os extratos praticamente nao modificaram o TTPA (1,95 e 2 UI [mg.sup.-1] para M I e M II, respectivamente). Os resultados r