Bioactive compounds from marine microalgae

Marine microalgae are relatively unexploited but rich resources for bioactive compounds. Toxins initially isolated from fish or shellfish were found to originate from microalgae, especially dinoflagellates. These toxins are useful tools to investigate the structure and function of ion channels on cell membranes or to elucidate the mechanism of tumor promotion based on their specific inhibitory action against protein phosphatases. The number of antifungal or antitumoral substances of microalgal origin is rapidly increasing. More importantly, structural similarities have been found between many bioactives found in marine invertebrates and those in freshwater blue-green algae. The similarities point to a great potential of marine blue-greens, the least explored resource, for producing bioactive compounds of medicinal value.