Costa, Leandro SilvaSoeiro, Vinícius Campelo2020-09-212020-09-212020-08-07SOEIRO, Vinícius Campelo. Avaliação do potencial antioxidante, antibacteriano e antibiofilme de polissacarídeos sulfatados obtidos da alga verde Codium isthmocladum. 2020. 126f. Tese (Doutorado em Bioquímica) - Centro de Biociências, Universidade Federal do Rio Grande do Norte, Natal, 2020.https://repositorio.ufrn.br/jspui/handle/123456789/30149The green macroalgae Codium isthmocladum it is a bioactive sulfated polysaccharide (SP) rich source. In addition to being found in abundance on Rio Grande do Norte coast, the SP of this alga have already been described in terms of their anticoagulant and antinociceptive potential in previous studies. In this context, the seaweed SP were evaluated for antioxidant capacity in several in vitro systems, as well as the potential of these compounds as possible antibacterial and antibiofilm agents against susceptible and multi-resistant bacteria in vitro. After collected, the seaweed was treated in order to obtain an isolate polysaccharides-rich (crude extract). From a subsequent fractionation of this extract, five ketone fractions were obtained (Ci 0.3, Ci 0.5, Ci 0.7, Ci 0.9 and Ci 1.2). All fractions have a low proteins and phenolic compounds content (< 1%). Ci 0.7 is the fraction with the highest yield and sulfate content. All polysaccharides showed antioxidant capacity, acting as potent hydroxyl and superoxide radicals scavengers, as well as a chelator of copper and iron ions. However, only Ci 0.7 and Ci 0.9 were able to inhibit the growth of resistant Staphylococcus aureus (MRSA) and Escherichia coli in adjuvance to several antibiotics, especially with gentamicin and ampicillin. Both fractions were subjected to ion exchange chromatography and tend to generate two chromatographic peaks at different molarities, eluted with 1.0 M and 2.0 M NaCl, respectively for Ci 0.7, and 2.0 M and 3.0 M NaCl for Ci 0.9. Based on the data obtained from chemical and structural analyzes, it is possible to state they are sulfated galactans. Galactans from Ci-0.7-1M and Ci-0.9-3M showed antibacterial and antibiofilm capacity, especially in adjuvance to antibiotics, as well as decreasing the expression pattern of various proteins. Therefore, sulfated galactans from C. isthmocladum are promising biomolecules in possible pharmacological treatments, especially as an antibacterial and antibiofilm compounds.Acesso AbertoGalactanas sulfatadasPurificaçãoAdjuvânciaStaphylococcus aureus resistente (MRSA)Escherechia colidoctoralThesis