Date of Award
1-1-2025
Document Type
Dissertation
Degree Name
Ph.D. in Pharmaceutical Sciences
First Advisor
Sudeshna Roy
Second Advisor
John M. Rimoldi
Third Advisor
David A. Colby
School
University of Mississippi
Relational Format
dissertation/thesis
Abstract
Opportunistic fungal pathogens, such as Cryptococcus neoformans, pose a significant public health risk, particularly for immunocompromised individuals. C. neoformans, a ubiquitous environmental yeast, can cause severe meningitis, which is often life-threatening and considered a global health threat. Responsible for over 112,000 deaths annually, particularly among individuals with advanced HIV/AIDS, C. neoformans has been classified as a critical fungal pathogen by the World Health Organization (WHO). The limited effectiveness of current treatments highlights the urgent need for novel antifungal therapies. The existing antifungal arsenal is not only small but also faces challenges such as drug resistance, toxicity, and a narrow spectrum of activity. Our initial findings highlight the potential of cysteine mimetics as effective inhibitors of C. neoformans, with minimum inhibitory concentration (MIC) values ranging from 1 to 128 μg/mL and potent fungicidal activity. These promising results underscore the potential of amino acid mimetics as a novel class of antifungal agents. Given the pressing need for more effective treatments against opportunistic fungal infections, particularly in immunocompromised individuals, our research aims to build upon these findings by further exploring structure-activity relationships (SAR). Ultimately, our work seeks to address the critical gap in the antifungal drug arsenal and contribute to the development of more effective therapies for combating fungal pathogens.
Further complementing this effort are the direct fluorination strategies for both 1,2,3-triazoles and 1,2,4-triazoles. Notably, we developed the first transition-metal-free defluorinative cycloaddition of gem-difluoroalkenes with organic azides using morpholine as a solvent. This method enables the synthesis of fully decorated morpholine-substituted 1,2,3-triazoles, which are otherwise challenging to access, from readily available starting materials. Mechanistic studies reveal the formation of an addition–elimination intermediate between morpholine and gem-difluoroalkenes before triazolization, proceeding via two plausible pathways. The straightforward and regioselective nature of this approach offers an attractive means for synthesizing fully substituted 1,2,3-triazoles.
Recommended Citation
Djugovski, Mario, "Part 1: First-In-Class Amino Acid Mimetics Small Molecules as Antifungal Agents - A Structure Activity Relationship Study; Part 2: Synthetic Strategiesf Fluorinating Nitrogen-Containing Heterocycles and Morpholine-Mediated Defluorinative Cycloaddition of gem-Difluoroalkenes" (2025). Electronic Theses and Dissertations. 3270.
https://egrove.olemiss.edu/etd/3270