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Seaweeds are subject to numerous biological interactions and sometimes to extreme abiotic conditions, so they have developed among other defense mechanisms, the ability to produce biologically active substances. Thus, these organisms produce mainly terpenes and phenols. Among others, the antifungal activity, due to its importance in human and animal health and the production of agricultural products, has been the subject of several studies. In the present work, this activity was investigated in ten seaweeds extracts, by direct bioautography assays, compared to Colletotrichum lagenarium and disk diffusion assay, compared to Aspergillus flavus. The organisms studied were: Stypopodium zonale, Laurencia dendroidea, Ascophyllum nodosum, Sargassum muticum, Pelvetia canaliculata, Fucus spiralis, Sargassum filipendula, Sargassum stenophyllum, Laminaria hyperborea and Gracilaria edulis. S. zonale, L. dendroidea, P. canaliculata, S. muticum, A. nodosum and F. spiralis extracts significantly inhibited the C. lagenarium growth, but not inhibited significantly the A. flavus growth. The presence of terpenes in all of these extracts was confirmed by thin layer chromatography whereas the presence of phenolic compounds was confirmed only in extracts of P. canaliculata, A. nodosum and S. muticum. In chemical study by column chromatography, followed by gas chromatography/mass spectrometry analysis, the terpenes neophytadiene, cartilagineol, obtusol elatol; and the ester ethyl hexadecanoate were identified in the L. dendroidea extract. This is the first report on the activity of seaweed extracts against C. lagenarium, a fungus bearing agricultural importance.Index terms: Etanolic extract, Colletotrichum lagenarium, Aspergillus flavus. RESUMOAs macroalgas marinhas, por estarem sujeitas a numerosas interações biológicas e, por vezes, a condições abióticas extremas, desenvolveram, entre outros mecanismos de defesa, a capacidade de produzir substâncias biologicamente ativas. Assim, esses organismos produzem, principalmente, terpenos e fenóis. Entre outras, a atividade antifúngica, por sua importância na saúde humana e animal e na preservação de produtos agrícolas, tem sido objeto de diversos estudos. No presente trabalho, esta atividade foi investigada em dez extratos de macroalgas marinhas, por ensaios de bioautografia direta, frente ao fungo Colletotrichum lagenarium e por ensaio de difusão em disco, frente ao Aspergillus flavus.

Abstract:In Brazil, the Laurencia complex is represented by twenty taxa: Laurencia s.s. with twelve species, Palisada with four species (including Chondrophycus furcatus now that the proposal of its transference to Palisada is in process), and Osmundea and Yuzurua with two species each. The majority of the Brazilian species of the Laurencia complex have been phylogenetically analyzed by 54 rbcL sequences, including five other Rhodomelacean species as outgroups. The analysis showed that the Laurencia complex is monophyletic with high posterior probability value. The complex was separated into five clades, corresponding to the genera: Chondrophycus, Laurencia, Osmundea, Palisada, and Yuzurua. A bibliographical survey of the terpenoids produced by Brazilian species showed that only six species of Laurencia and five of Palisada (including C. furcatcus) have been submitted to chemical analysis with 48 terpenoids (47 sesquiterpenes and one triterpene) isolated. No diterpenes were found. Of the total, 23 sesquiterpenes belong to the bisabolane class and eighteen to the chamigrene type, whose biochemical precursor is bisabolane, two are derived from lauranes and four are triquinols. Despite the considerable number of known terpenes and their ecological and pharmacological importance, few experimental biological studies have been performed. In this review, only bioactivities related to human health were considered.

Recebido em 8/10/99; aceito em 18/4/00 HALOGENATED AND/OR SULFATED PHENOLS FROM MARINE MACROALGAE. During the biological evolution, marine macroalgae have developed biochemicals tools in order to utilize components of seawater such as sulfates and halogens, to produce a variety of chemicals (secondary metabolites).This review shows and discuss the occurrence of sulfated and/or halogenated phenolic compounds in seaweeds.Keywords: seaweed; halogenated phenols; sulfated phenols. REVISÃO INTRODUÇÃOO oceano é resultado de uma gigantesca reação ácido -base, onde os ácidos que continuamente afloram do interior da terra são misturados com bases que estão sendo liberadas constantemente das rochas, pela ação do tempo. Suas águas são comparadas a um meio de cultura de composição praticamente constante, o que é verdadeiro para a quase totalidade de seus parâmetros, como por exemplo a porcentagem dos sais dissolvidos, que mantem-se em torno de 3,5%. Este equilíbrio é sustentado por uma série de reações químicas e de processos físico-químicos 1,2 . A vida teve origem nos oceanos. Nesse imenso laboratório, os organismos aquáticos e o ambiente abiótico estão interrelacionados e interagem entre si. Por isso, organismos marinhos adaptaram-se às altas concentrações de sais do meio e desenvolveram mecanismos para utilizar os solutos disponíveis 3,4,5 . Dentre os mais importantes íons presentes no ambiente marinho estão o sulfato, o cloreto, o brometo e o iodeto, em concentrações de 885, 19000, 65, e 0,06 mg.L -1 , respectivamente 1,2 . Portanto, não é de surpreender que os organismos marinhos produzam substâncias halogenadas e sulfatadas em abundância, com maior ou menor eficiência.De todos os organismos marinhos produtores dessas substâncias, sobressaem as algas vermelhas (Rhodophyta), capazes de sintetizar metabólitos halogenados da mais fascinante diversidade, que podem pertencer a praticamente todas as classes químicas, desde hidrocarbonetos de baixo peso molecular, cetonas simples, fenóis, acetogeninas até sofisticados terpenos 3 . Além disso, são eficientes na produção de polissacarídeos sulfatados, os carragenanos e o ágar, que chegam a representar mais de 70 % do seu peso seco e que têm razoá-vel valor comercial 6,7,8,9 . As algas marinhas pardas (Phaeophyta) e verdes (Chlorophyta) são menos eficientes na produção de substâncias halogenadas, sendo que ambas, e particularmente as pardas, apresentam polissacarídeos sulfatados 7,8 . As macroalgas marinhas pertencem ao grupo não homogêneo de organismos denominado "Algae", que se encontra subdividido entre os Reinos Monera e Protista. Esses organismos são fotossintetizantes, não vasculares, contêm clorofila a e apresentam estruturas reprodutivas simples, isto é, sem a proteção de células esteréis 8,10,11 .Enquadram-se nesse conceito desde corpús-culos unicelulares microscópicos até os gigantescos "kelps", algas pardas (Phaeophyta) gigantescas que podem alcançar 60m de comprimento. Tal variedade de organismos encontra-se distribuída por diferentes "habitats": oceanos, corpos de á...

-(Cyanobacterial occurrence and detection of microcystins by planar chromatography in surface water of Billings and Guarapiranga Reservoirs, SP, Brazil). Billings and Guarapiranga Reservoirs were deeply affected by environmental disturbances, which more evident consequence are the cyanobacterial blooms. Microcystins are the most common cyanotoxin in freshwaters and more than 70 types are known. Different methods for microcystins analysis in water can be used, among which ELISA and HPLC are the most frequently employed. However, less sophisticated and more economic methods can also be used. This is the case of planar chromatography (thin-layer chromatography) method previously used in cyanotoxins purification but gradually replaced by others. Posterior optimization of the microcystin chromatography conditions and because of its simplicity, rapidity, efficiency and low cost, this method is again considered an option for the analysis of microcystins and nodularins. Considering the importance of Billings and Guarapiranga Reservoirs for drinking water supplies and the few scientific data about cyanobacteria and cyanotoxins in these water bodies, the aims of this work are to analyze the biodiversity of cyanobacteria in the Billings and Guarapiranga Reservoirs and the detection of dissolved microcystins in the water. It was possible to identify 17 species of cyanobacteria, 9 of them being potentially toxic. In Billings Reservoir Microcystis aeruginosa (Kützing) Kützing and Cylindrospermopsis raciborskii (Woloszynska) Seenayya & Subba Raju are the most common species, while in Guarapiranga Reservoir only M. aeruginosa was considered as a common species. Microcystins were detected in all Billings Reservoir samples and in only one sample from Guarapiranga Reservoir.Key words -cyanobacteria, drinking water, microcystins, planar chromatography, reservoirs RESUMO -(Ocorrência de cianobactérias e detecção por cromatografia planar de microcistinas dissolvidas nas águas superficiais das represas Billings e de Guarapiranga, SP, Brasil). As represas Billings e Guarapiranga foram profundamente afetadas por fatores ambientais cuja conseqüência mais evidente são as florações de cianobactérias. As microcistinas formam a classe de cianotoxinas mais freqüente em água doce e são comumente analisadas por ELISA ou CLAE. No entanto, processos menos sofisticados e mais econômicos também podem ser usados. Este é o caso da cromatografia planar (cromatografia em camada delgada), método anteriormente usado em trabalhos de purificação de cianotoxinas, mas que foi gradualmente substituído por outros. Assim, considerando a importância das represas Billings e Guarapiranga para o abastecimento público e a carência de informações científicas sobre as cianobactérias e as cianotoxinas que nelas ocorrem, nossos objetivos foram o estudo da composição desses organismos e a detecção de microcistina dissolvida na água. Foi possível identificar 19 espécies de cianobactérias, das quais 9 são consideradas potencialmente tóxicas. Microcystis aeruginosa...

Cyanobacteria are common members of the freshwater microbiota in lakes and drinking water reservoirs, and are responsible for several cases of human intoxications in Brazil. Pseudanabaena galeata and Geitlerinema splendidum are examples of the toxic species that are very frequently found in reservoirs in Sao Paulo, which is the most densely populated area in Brazil. In the search for toxic strains collected from water reservoirs and maintained in the Cyanobacterial Culture Collection (CCIBt) of the Institute of Botany of Brazil, the acetic acid extracts (AE) of P. galeata CCIBt 3082 and G. splendidum CCIBt 3223 were analyzed by planar chromatography, which indicated the absence of cyanotoxins. Animal tests were then carried out, and both extracts were found to induce toxic effects in mice when administered intraperitoneally. The present study aimed to investigate whether the oral ingestion of the above mentioned cyanobacteria extracts would also induce toxic effects in mice. Necropsy and histopathological studies were conducted using tissue samples from the animals, which were euthanized one week after the administration of the extracts. The AE of P. galeata did not cause death but did induce transient symptoms, including eyebrow ptosis, straub tail, and pain. The euthanized animals presented hemorrhage in the liver, whereas the histological analysis showed disorganization of the hepatic parenchyma, necrosis, hyperemia, and proximity of the centrilobular vein in the liver. In addition, alterations in the convoluted tubules of the kidneys were observed, and the lungs were unaffected. The AE of G. splendidum caused only one death, and induced transient symptoms, such as dyspnea, paralysis, and pain, in the other mice. The necropsy of the euthanized mice showed hemorrhage in the lungs and liver. The lungs presented hemorrhagic focuses, alveolar collapse, and granulomatous foci. The liver presented hemorrhagic and enlarged sinusoids, hyperemia, proximity of the centrilobular vein, and disorganization of the hepatic parenchyma. Some areas also exhibited an inflammatory infiltrate and calcified tissue inside blood vessels. Necrosis and rupture of the convoluted tubule cells were observed in the kidneys. Further analysis of the both extracts indicated the lack of hemolytic activity, and the presence of two unknown anti-AChE substances in the AE of G. splendidum. Thus, P. galeata and G. splendidum are producers of novel toxins that affect mammals when administered orally.

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