Biopharmaceuticals from Algae Fight AIDs

Marine drug discovery is making headway into the fight against AIDs. New generations of anti-virals isolated from phototrophic organisms (those that derive energy from light) show promise for the treatment of a number of diseases. The pharmaceuticals are a class of sulfur-containing lipid found in plants called sulfoquinovosyl diacylglycerol (SQDG). SQDGs are antibacterial and have antiviral properties, specifically against the AIDs and Herpes viruses. They are also promising for a number of other uses, such as enhancing radiosensitivity during combination therapy with radiation and antiangiogenesis drugs, in the treatment of cancer.

The new SQDGs, currently under investigation by the University of Erlangen-Nuremburg, Germany, are produced by algae. Most plants do produce SQDGs, but the compounds from higher plants are different and more complex. In order to produce enough SQDG, algae is grown in tall chambers surrounded by light. The products are harvested and isolated by TLC and solid-phase extraction methods. Generating enough biomass has presented a challenge in the past, and new methods for producing them in bulk quantities, are being developed. Testing and screening of new SQDGs is also problematic, and the development of new bioassays is required to effectively test them. However, several years ago, the discovery of genes for the sulfur-containing lipids, allowed scientists to investigate the potential for their overexpression in fast-growing GMOs, and mass production of these versatile compounds.

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Benning, C., Garavito, R.M., and Shimojima, M. 2008. Sulfur Metabolism in Phototrophic Organisms: Sulfolipid Biosynthesis and Function in Plants. In: Advances in Photosynthesis and Respiration. Rudiger Hell et al. (eds). p 185-200. Springer. Sakimoto et al. 2006. Alpha-sulfoquinovosylmonoacylglycerol is a Novel Potent Radiosensitizer Targeting Tumor Angiogenesis. Cancer Research 66, 2287-2295.