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Data of Thesis


Author: Simone Maciel da Costa Gouvea

Title: Antimicrobial activity of compounds isolated from strains of cyanobacteria family Oscillatoriaceae.

Year: 1998.    Full text (in Portuguese)


Biological activity of secondary metabolites produced by cyanobacteria have been studied due to their importance in biotechnology and/or pharmacology. These metabolites have a wide spectrum of activity: while: allelopathic, algicidal; antibacterial, antifungal, antineoplastic, cytotoxic, antiviral, enzyme inhibitors and inflammatory. Biotechnological potential of polar extracts of some strains of cyanobacteria (Oscillatoriales) of Brazilian water bodies were evaluated through the following biological tests: diffusion tests, platelet aggregation, antiviral and cytotoxic activity. In diffusion tests, the better results were with MeOH 80% (N) extracts of the strains NPCD-2 (Limnothrix sp), NPDF-2 (Leptolyngbya sp) and NPBT-l (Tychonema sp) strains against Candida albicans. However the extract lost activity when the strains were subcultured for long periods, probably due to a decreased production of the bioactive metabolite. In the platelet aggregation tests, the extracts (N) and (I) of NPFX -1 - Leptolyngbya sp (MeOH 20%), NPFE-l - Tychonema sp (MeOH 20%) and NPCD-2- Limnothrix sp (H20) strains, were able to induce a natural platelet aggregation in the absence of the agonists ADP and P AF. This result suggests indirectly a potential inflammatory activity of these extracts. Nevertheless antiviral tests showed no activity against HSV -1 (Herpes simplex virus - type 1). Cytotoxic tests showed that the aqueous extracts of NPRG-l, NPDF-2 and NPRE-3 strains, both Leptolyngbya sp (Pseudoanabaenaceae) genera, can provide important information to developed new anti-cancer drugs. These results confirm the potential of extracts of cyanobacteria from the order Oscillatoriales as a promising source of new bioactive metabolites and could provide subsidy to future investigations chemical and biotechnological.