Antimicrobial (including antimollicutes), antioxidant and anticholinesterase activities of Brazilian and Spanish marine organisms – evaluation of extracts and pure compounds

AbstractThis work describes the antimicrobial, antioxidant and anticholinesterase activities in vitro of organic extracts from fourteen seaweeds, eleven sponges, two ascidians, one bryozoan, and one sea anemone species collected along the Brazilian and Spanish coast, as well as the isolation of the diterpene (4R, 9S, 14S)-4α-acetoxy-9β,14α-dihydroxydolast-1(15),7-diene (1) and halogenated sesquiterpene elatol (2). The most promising antimicrobial results for cell wall bacteria were obtained by extracts from seaweeds Laurencia dendroidea and Sargassum vulgare var. nanun (MIC 250μg/ml), and by the bryozoan Bugula neritina (MIC 62.5μg/ml), both against Staphylococcus aureus. As for antimollicutes, extracts from seaweeds showed results better than the extracts from invertebrates. Almost all seaweeds assayed (92%) exhibited some antimicrobial activity against mollicutes strains (Mycoplasma hominis, Mycoplasma genitalium, Mycoplasma capricolum and Mycoplasma pneumoniae strain FH). From these seaweeds, A1 (Canistrocarpus cervicornis), A11 (Gracilaria sp.) and A4 (Lobophora variegata) showed the best results for M. pneumoniae strain FH (MIC 250μg/ml). Furthermore, compounds 1 and 2 were also assayed against mollicutes strains M. hominis, M. genitalium, M. capricolum, M. pneumoniae strain 129 and M. pneumoniae strain FH, which showed MIC>100μg/ml. Antioxidant activities of extracts from these marine organisms were inactive, except for E7 (from sponge Ircinia sp.), which exhibited moderated antioxidant activities for two methods assayed (IC50 83.0±0.1μg/ml, and 52.0±0.8mg AA/g, respectively). Finally, for the anticholinesterase activity, all the 29 samples evaluated (100%) exhibited some level of activity, with IC50