Introduction: Snow algae grow under extreme conditions of temperature and high exposure to ultraviolet (UV) radiation. These organisms must have evolved ways to protect their cellular components from the harmful effects of UV. Snow algae, consequently, may produce compounds of benefit for protecting humans from skin cancer and other diseases resulting from exposure to UV light. This investigation ... (ASAC project #1099 in 2001) collected snow algae from various locations around Casey Station and the Windmill Islands, Antarctica. One of the primary goals was to examine algal extracts for UV-protecting compounds.
Samples: Snow algal samples were returned to the laboratory in the US for characterization and analysis. Algae were identified, photomicrographed, characterized, compared to cultured snow algae and collecting results made in previous years (Ling).
Methods/chemical analysis: Upon return to the US snow algae were processed in the following manner: green snow algae from Churchill Point (Ulothrix and Chloromonas species) and red snow algae collected from Sparkes Bay (Chlorosarcina and Chloromonas polyptera), were compared to cultured green snow algae (Chloromonas sp.). The Antarctic snow algae in melt water was centrifuged and the pellet resuspended in distilled water, sonicated and extracted with 2 X 4 ml ethyl acetate. The cultured snow algae was filtered and sonicated in water, then extracted with 2 X 4 ml ethyl acetate. After removal of the solvent the sample was either analyzed directly or converted to the TMS derivative prior to GC/MS analysis. Tentative structural assignments are based on the NIST mass spectral library and are summarized in the attached table.
Preliminary results: Chromatograms and mass spectra of the free and TMS derivatized ethyl acetate soluble components of the cultured and two samples of the wild (Antarctic) snow algae have been compared using GC/MS methods. Structural assignments of the various components were based on a comparison of the unknown spectrum of the sample with NIST mass spectral library spectra; the structures are tentative. The samples differ in their complexity, with the cultured green snow algae showing major components distributed fairly evenly across the chromatogram. The wild green snow algae has components concentrated above the 13.5 min region of the chromatogram, with fewer components in the lower MW range. In contrast, the red snow algae (collected primarily at Sparkes Bay and Newcombe Bay near Casey), have a higher concentration of lower MW components than the other samples. Differences are also evident in the presence/absence of major components in the chromatograms.
The fields in this dataset are: