Bioactive meroditerpenes from Cystoseira abies-marina, collected from the coast of S. Miguel island

Abstract

Many substances isolated from marine organisms have demonstrated to possess interesting biological and pharmacological activities and have been used as leads in the development of new pharmaceutical agents. Marine macroalgae are abundant and structuring organisms of the coastal area of all the islands in the Azores Archipelago; some have a markedly seasonal pattern and others are perennial and present during the whole year in the Azorean coasts. One of these is Cystoseira abies-marina which grows abundantly in the coast of the Azores archipelago. Interestingly, it was observed in situ that this alga was not attacked by common predators, such as marine gastropods which led to the suggestion that the great resistance to predation of this species was due to the presence of potentially active compounds, such as antifeedant and/or cytotoxic. Preliminary study on the extracts of Cystoseira abies-marina, collected in S. Miguel Island, showed very promising results for antitumour and antioxidant activities [3]. These results have increased our interest in this alga and led to its phytochemical study. Recently, we have reported the isolation and identification of benzoic acid and two new meronorsesquiterpenes [Cystoazores A (1) and Cystoazores B (2)] from the extracts of this marine alga [4]. Further investigation of this species led to isolation of other two new meroditerpene derivatives (3 and 4). We report here the isolation of the compounds 3 and 4, from Cystoseira abies-marina whose structures were established by 1D and 2D NMR spectral analysis as well as by MS. Additionally, the cytotoxic, anti-inflammatory and antioxidant activities of compounds 1-4 were evaluated and the results will be presented.