University of St. Thomas' 2004 Research Symposium, Abstract Three

University of St. Thomas featuring:

Performing a GC/MS Technique to Study Secondary Metabolites of Lichens*...

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This experiment continues with the study of secondary metabolites in lichens. However, the experimenters did not primarily focus on the bioactivity of various fractions (the metabolites) extracted from the experiment, but rather, they were interested in identifying the different kinds of secondary metabolites in lichens and to determine their structures. In order to do this, they used the lichens of the genus Ramalina, which were collected from Spain, and then pulverized them in liquid nitrogen. After this, the pulverized lichens were extracted with acetone and were then further separated into ether soluble and insoluble fractions. Once the fractions were derivatized with BSTFA to cap the –OH and –COOH groups, they were then analyzed by the gas chromatography mass spectrometry (GC/MS). Electron and chemical ionizations were used along with several reagent gases like isobutene. (Oviedo commented that they could have used ammonia in the experiment, but didn't.)

In addition to these experimental procedures, the experimenters compared these possible matches to the metabolites that were already known and identified in previous lichen samples by taking note of the molecular weights (measured in Daltons) and major fragment ions of the fractions. The experimenters used a chart of the various known and identified metabolites to perform this procedure in order to identify the structures of the metabolites. Furthermore, the experimenters also found many other structures of metabolites that were found in their sample of lichens that were not previously reported yet. However, possible structures were proposed, and hopefully, future experiments would be conducted.

Literature Cited

Oviedo C, Cocciani R. Electron and chemical ionization mass spectrometry characterization of secondary metabolites extracted from lichens. 2004 UST Research Symposium; 2004 Apr 16; Houston (TX) at Crooker Center: [the program booklet], pg. 29.

--Reviews by Kathy Nguyen, 2004.

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* The full-length abstract is not displayed for public view, because it is compiled in the UST's 2004 Research Symposium program booklet. For more information on what the Research Symposium is, please visit the site: The UST Research Symposium.