Chemical Ecology of Marine Cyanobacterial Secondary Metabolites: a Mini-review

More than 300 nitrogen-containing secondary metabolites have been reported from the procaryotic marinecyanobacteria. A majority of these compounds are of the polypeptide or mixed polyketide-polypeptidestructural class and they are a potential source of novel pharmaceuticals. In spite of the chemical richnessof marine cyanobacteria, not much is known regarding their ecological functions. To date only a handful ofmarine cyanobacterial compounds have been examined for their involvement in predator-prey interactions.This mini-review surveys the various chemical ecology studies conducted on marine cyanobacterialcompounds. From these ecological studies, many marine cyanobacterial compounds are known to deterfeeding by several species of marine predators. Such chemical defense may be crucial in maintaining thepopulation of marine cyanobacterial bloom in nature. In addition, a series of ecological studies from ourlaboratory revealed the anti-settlement properties of a number of benthic marine cyanobacterialcompounds. These studies suggested marine cyanobacteria as a potential source of natural antifoulants forthe control of fouling organisms

Chemical Ecology of Marine Cyanobacterial Secondary Metabolites: a Mini-review

More than 300 nitrogen-containing secondary metabolites have been reported from the procaryotic marinecyanobacteria. A majority of these compounds are of the polypeptide or mixed polyketide-polypeptidestructural class and they are a potential source of novel pharmaceuticals. In spite of the chemical richnessof marine cyanobacteria, not much is known regarding their ecological functions. To date only a handful ofmarine cyanobacterial compounds have been examined for their involvement in predator-prey interactions.This mini-review surveys the various chemical ecology studies conducted on marine cyanobacterialcompounds. From these ecological studies, many marine cyanobacterial compounds are known to deterfeeding by several species of marine predators. Such chemical defense may be crucial in maintaining thepopulation of marine cyanobacterial bloom in nature. In addition, a series of ecological studies from ourlaboratory revealed the anti-settlement properties of a number of benthic marine cyanobacterialcompounds. These studies suggested marine cyanobacteria as a potential source of natural antifoulants forthe control of fouling organisms

Diversity, Distribution and Biological Activity of Soft Corals (Octocorallia, Alcyonacea) in Singapore

The Southern Islands of Singapore are known to contain coral reefs which are high in biodiversity. However, the diversity of soft corals had received little attention to date. This study was conducted to determine the soft coral diversity in Singapore reefs as well as to conduct preliminary bioactivity tests on the organic extracts from these soft corals. A 100-meter line transect was used to survey soft corals at a 3m depth at ten different sample sites. Sclerites from samples were used to identify the soft corals to the generic level. This study uncovered the following genera of soft corals: Carijoa spp., Cladiella spp., Sinularia spp., Lobophytum spp., Sarcophyton spp., Stereonephthya spp., and Nephthea spp. In addition, an unidentified genus of soft coral was observed at Kusu Island. Cladiella spp. yielded the highest number of colonies, and Sarcophyton spp. had the highest coverage in terms of total colony diameter. The brine shrimp (Artemia salina) toxicity assay was carried out to screen for toxicity of the soft coral extracts at concentrations of 10, 100, and 1000 ppm. Results showed high levels of toxicity in extracts of Sarcophyton spp. and Cladiella spp., indicating that these soft corals are potentially good sources of bioactive compounds for drug discovery