Geographic Distribution of Natural Products Produced by the Red Alga Laurencia dendroidea J. Agardh.

In order to evaluate the chemical diversity of Laurencia dendroidea J. Agardh, a widely distributed seaweed in Brazilian coast, a phytochemical study was carried out with algae collected from six different locations along the Southeast Brazilian coast. Purified compounds were identified by MS and NMR techniques. The chemical profiles of lipophilic extracts were obtained by GC/MS for each population. In total, 15 compounds were described. The sesquiterpene composition accounted for 49 - 63% of the GC/MS chromatogram area. The discrimination of three chemotypes was done by the use of HCA on GC/MS chromatograms. They were also analyzed by the PCA and, together with peak area analysis, it was possible to discriminate all populations by the main variation of elatol, obtusol, rogiolol, and triquinane. The results revealed the high diversity of sesquiterpene composition among populations of L. dendroidea. Curiously, the within and among population variation of elatol and obtusol suggested a biochemical interplay on the content of these compounds. More studies are necessary to understand the patterns of chemical diversity and compound variation within and among populations of L. dendroidea.

Antiviral activity of extracts from Brazilian seaweeds against herpes simplex virus

Organic extracts of 36 species of marine algae (sixteen species of Rhodophyta, eight species of Ochrophyta and twelve species of Chlorophyta) from seven locations on the Brazilian coast were evaluated for their anti-HSV-1 and anti-HSV-2 activity resistant to Acyclovir (ACV). Activity tests in crude extracts, followed by the identification of the major compounds present, were performed for all species. The chemical profiles of all crude extracts were obtained by ¹H-NMR and 13C-NMR spectroscopy. The percentage of extracts with antiviral activity was higher for HSV-1 (86.1%) than for HSV-2 (55.5%). The green algae Ulva fasciata and Codium decorticatum both showed the highest activity (99.9%) against HSV-1, with triacylglycerols and fatty acids as the major components. The red alga Laurencia dendroidea showed good activity against HSV-1 (97.5%) and the halogenated sesquiterpenes obtusol and (-)-elatol were identified as the major components in the extract. Against HSV-2, the green alga Penicillus capitatus (Chlorophyta) and Stypopodium zonale (Ochrophyta) were the most active (96.0 and 95.8%). Atomaric acid, a meroditerpene, was identified as the major secondary metabolite in the S. zonale extract. These results reinforce the role of seaweeds as important sources of compounds with the potential to enter into the pipeline for development of new drugs against herpes simplex.