Rocha, Hugo Alexandre de OliveiraQuieregati, João Pedro Bauman2021-10-262021-10-262021-09-17QUIEREGATI, João Pedro Bauman, Extração e quantificação de Polissacarídeos Sulfatados da Microalga Nannochloropis Oculata e Avaliação da Atividade Antioxidante In Vitro. 2021. 40. Trabalho de Conclusão de Curso (Graduação em Química-Bacharelado) - Instituto de Química, Universidade Federal do Rio Grande do Norte, Natal, 2021.https://repositorio.ufrn.br/handle/123456789/44710Much of the extension of planet Earth is covered by marine or fresh waters, and in this there are several organisms from the simplest to the most complex, among the many can stand out as algae. Marine microalgae have an ability to synthesize during their lifetime carotenoids, long chain unsaturated fatty acids, polysaccharides, in some rare cases sulfated polysaccharides (PS). However, these SP from microalgae usually have different pharmacological activities. Within this context, we can mention the microalgae Nannochloropsis oculata, whose ability to synthesize PS was demonstrated in 2019. It was also that a polysaccharide-rich extract from N. oculata has antioxidant activity, but it was not identified whether this activity come from PS. Therefore, to fill this gap, this work aimed to extract PS from N. oculata and evaluate them as antioxidant agents in different in vitro tests. Therefore, a freeze-dried seaweed was delipidated with methanol:chloroform (1: 2 v/v) and subsequently macerated (NaCl, 0.25 M, 4 h, 65 °C). After centrifugation (8000 x g, 4 °C, 20 min), the supernatant was lyophilized and named crude extract. This was subjected to ion exchange chromatography (TKSgel DEAE-5PW resin) and 4 fractions were displaced. Chemical dosages and agarose gel electrophoresis confirmed the presence of PS in the 1.0M fraction. The antioxidant activity of this fraction was evaluated in 4 in vitro tests: iron chelation; copper chelation; reducing power, total antioxidant capacity (CAT). In the first three tests the sample revealed low activity. However, in the CAT test, 1 g of the sample showed an activity equivalent to approximately 118 mg of ascorbic acid. As far as we know, this is the biggest CAT activity ever identified for a PS. It is expected in the future to chemically characterize the PS of N. oculata, as well as its antioxidant activity(ies) in vivo.Attribution 3.0 Brazilhttp://creativecommons.org/licenses/by/3.0/br/polissacarídeos sulfatados(PS)Nannochloropsis oculatamicroalgasatividades antioxidantebachelorThesis