Thesis (Ph. D.)--University of Texas at Austin, 2006. / Vita. Includes bibliographical references.

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Dissertation (Ph.D.) -- University of Texas Southwestern Medical Center at Dallas, 2006. / Vita. Bibliography: pp. 409-414

My investigations of the natural products of marine algae have resulted in the discovery of several new secondary metabolites. Bioassay-guided fractionation led to the isolation of these new compounds and spectroscopic analysis was utilized in their structural characterization. Two new and potent antimitotic metabolites, curacins B and C, were isolated from a Curacao collection of Lyngbya majuscula. In addition, four curacin A analogs were prepared by semisynthetic methods. The structures of the new curacins and the curacin A analogs were determined by spectroscopic analysis in comparison with curacin A. The biological properties of the new natural products and synthetic derivatives of curacin A were examined. Investigations of another Curacao collection of L. majuscula revealed a new cytotoxic lipopeptide, microcolin C. Microcolin C was found to have an interesting profile of cytotoxicity to human cancer-derived cell lines. A new metabolite, vidalenolone, was isolated from an Indonesian red alga Vidalia sp. The structure of this new cyclopentenolone-containing compound was determined by a combination of spectroscopic methods. Filamentous cells isolated from female gametophytes of the brown alga Laminaria saccharina were cultured in flasks or bioreactors. These cultures produced a variety of w6-lipoxygenase metabolites: 13-hydroxy-9,11-octadecadienoic acid (13-HODE), 13-hydroxy-6,9,11,15-octadecatetraenoic acid (13-HODTA), and 15-hydroxy-5,8,11,13-eicosatetraenoic acid (15-HETE). Five oxidized anandamide derivatives were prepared from anandamide through autoxidation in an exploration of ligand binding to the cannabinoid receptor. Their structures were determined by a combination of NMR spectroscopy and GC-MS. The cannabinoid receptor binding affinity of these derivatives was evaluated. This study revealed the following trend in activity: anandamide > 15- > 9- > 8- > 11- > 5-hydroxyanandamide. / Graduation date: 1998

An introduction, background and research progress in the areas of antifolates, receptor tyrosine kinase (RTK) inhbitors and antimitotic agents has been discussed. <br>Thymidylate synthase (TS), dihydrofolate reductase (DHFR) and glycinamide ribonucleotide formyltransferase (GARFTase) are important folate dependent enzymes that are targets for cancer chemotherapy and the treatment of infectious diseases. Classical antifolates, in most cases, are substrates for folypoly-g-glutamate synthase (FPGS) and rely on folate transporter systems to enter cells. As a part of this study, twenty-eight compounds were designed on the basis of existing clinically active compounds and crystal structures, synthesized and evaluated as single and/or muliple targeted classical and nonclassical antifolates to decrease toxicity and improve the activity and selectivity of existing therapeutic agents. In addition, these structures provides an extension to the structure activity relationship in the antifolate area. <br>RTK inhibitors and antimitotic agents are important antitumor agents and are extensively used in the clinic for the treament of various types of cancers. Pgp overexpression is one of the common reasons for drug resistance to existing antitumor agents and consequently the reason for some chemotherapeutic failures. A furo[2,3-d]pyrimidine compound was discovered to have dual RTK inhibitory activity along with antimitotic activity that circumvent pgp over expression. Antimitotic activity via the binding at the colchicine site is one of the mechanisms of action. Molecular modelling and biological evaluation suggest the importance of conformational restriction for activity. Fifty-seven furo[2,3-d]pyrimidines and six thieno[2,3-d]pyrimidines were designed on the basis of crustal structures and synthesized as potential RTK inhibitors with antimitotic antitumor activity. Four pyrrolo[2,3-d]pyrimidines were designed and synthesized as antimitotic anticancer agents that also reverse pgp action. / Mylan School of Pharmacy and the Graduate School of Pharmaceutical Sciences / Medicinal Chemistry / PhD / Dissertation

Thesis (Ph.D.)--University of Wyoming, 2008. / Title from PDF title page (viewed on August 9, 2009). Includes bibliographical references (p. 113-116).

Graduation date: 1997

Thesis (M. Phil.)--Hong Kong University of Science and Technology, 2003. / Includes bibliographical references (leaves 135-142). Also available in electronic version. Access restricted to campus users.

Thesis (Ph.D.)--University of Western Australia, 2005.