Isolation and Characterization of Natural Products from Marine Cyanobacteria Aided by Enhanced NMR Methodologies
- Author(s): Alexander, Kelsey Leigh
- Advisor(s): Gerwick, William;
- Burkart, Michael
- et al.
The natural world is an extraordinary source of diverse organisms and natural product compounds. The use of natural products and their derivatives has been a recurring theme in the discovery and development of new therapeutics. The marine world is vast and contains incredible biological and chemical diversity. Therefore, the oceans have the potential for new discoveries of compounds with medicinal applications. One group of marine organism that has been shown to be a prolific producer of bioactive compounds is the cyanobacteria. This work focuses on the study of new compounds from marine cyanobacteria for their chemical diversity and biological activity. The work in this dissertation focuses on the discovery and characterization of compounds from two different species of cyanobacteria, Leptolyngbya sp. and Moorena producens. These were collected from American Samoa and Puerto Rico, respectively. The characterization of these compounds was achieved through the integration of a variety of techniques including mass spectrometry, advanced NMR technology and genomic information. This analysis led to the characterization of a new ionophore from the Leptolygbya sp. The collection of Moorena producens afforded new analogues of the bioactive compound, curacin A. 2D NMR was an essential aspect in these studies. Therefore, the optimization of different NMR techniques for faster data acquisition was studied in this dissertation for its applications on lower concentrations of natural products. This work highlights the novelty of compounds that can be discovered by the application of the multiple techniques. Additionally, it demonstrates the reduction in time that is possible with new techniques for the experimental acquisition of NMR data. Finally, this dissertation adds to the body of knowledge of the chemistry that originates from the world’s oceans.