Aqueous and ethanolic extracts obtained from nine Chilean marine macro-algae collected at different seasons were examined in vitro and in vivo for properties that reduce the growth of plant pathogens or decrease the injury severity of plant foliar tissues following pathogen infection. Particular crude aqueous or organic extracts showed effects on the growth of pathogenic bacteria whereas others...

Bioactive polymers mainly polysaccharides such as cellulose, chitin, amylose and beta-glucan are well discovered from various sources in nature. Amongst chitin, as the second most abundant polysaccharides after cellulose, is known as a highly insoluble polysaccharide consisting of β-4-linked N-acetyl-D-glucosamine, which has been identified as a structural component of crustaceans, crabs, shrim...

The alxM gene encoding a D-mannuronan-specific alginate lyase has been cloned from a marine bacterium isolated as an epiphyte on the brown alga, Sargassum fluitans. Expression of this gene in Escherichia coli provides a source of this enzyme for probing alginate structure and modifying the mannuronan-rich alginate polymers produced by bacterial pathogens.

Marine brown alga Dictyota dichotoma (Dictyotaceae) collected from the Karachi coast of the Arabian Sea has yielded three new C-16 oxidized seco-dolastanes (diterpenoids) named dichotenol-A, B and C. Their structures have been characterized with the aid of 2D-NMR spectroscopic techniques.

Chemotaxonomic study of the diterpenes from the brown alga Dictyota menstrualis Valéria Laneuville Teixeira*, Diana Negrão Cavalcanti, Renato Crespo Pereira Departamento de Biologia Marinha, Universidade Federal Fluminense, C.P. 100.644, 24001-970, Niterói, RJ, Brazil b Programa de Pós-Graduação em Quı́mica Orgânica, Instituto de Quı́mica, Universidade Federal Fluminense, 24020-150, Niterói, RJ, ...

Bioassay-guided fractionation of an ethanol extract of the brown alga, Dictyota dichotoma, led to the isolation of a novel chlorine-containing perhydroazulene diterpene together with two known diterpenes, dictyolactone and sanadaol. The structure of the novel compound, named dictyol J, was elucidated on the basis of spectroscopic information. Dictyolactone showed the highest algicidal activity ...

The meroditerpenoids atomaric acid (1), epitaondiol (2) and the peroxylactone of 5'a-desmethyl-5'-acetylatomaric acid (3) were isolated from the Brazilian brown alga Stypopodium zonale collected in two localities (Búzios and Marataízes, RJ and ES States). These compounds showed strong anti-HSV-1 activity in vitro but neither of them inhibited the transcriptase reverse enzyme of HIV-1.