Widen, John2018-03-142018-03-142017-01https://hdl.handle.net/11299/194590University of Minnesota Ph.D. dissertation. January 2017. Major: Medicinal Chemistry. Advisor: Daniel Harki. 1 computer file (PDF); xii, 368 pages.Extra- and intracellular stimuli results in gene expression changes by controlling transcription factor activity. Transcription factors are at the hub of cellular signaling and are responsible for controlling virtually all cellular processes by binding DNA to directly modulate gene expression. Because transcription factors control many cell decisions based on cellular pathway signaling, aberrant transcription factor activity is involved in many human diseases, making them interesting targets for drug discovery. With the exception of nuclear receptors, which are the only class of transcription factors known to contain ligand-binding domains, there are no FDA approved drugs directly targeting transcription factors. Historically, transcription factors have been referred to as ‘undruggable’ protein targets. This is likely due to the difficulty in developing small molecules toward transcription factors because they typically contain no enzymatic activity, lack ligand binding pockets, and have non-discrete tertiary structure. Thus, directly targeting transcription factors with small molecules must occur at protein-protein or DNA-binding interfaces, which contain shallow binding pockets over large surface areas. One strategy to overcome the difficulty in directly targeting transcription factors at protein-protein and DNA-binding interfaces with small molecules is through targeting nucleophilic amino acids within protein or DNA binding surfaces. This thesis describes efforts in developing cysteine reactive small molecules for direct targeting of transcription factors. Small molecule probes containing a cysteine reactive group(s) were developed, which were inspired by natural products. Chapter 2 discusses the design and synthesis of bis-electrophile probes based on the pseudoguaianolide natural product helenalin to target the transcription factor p65 of the NF-κB (p50/p65) heterodimer. Chapter 3 describes the synthesis and testing of additional helenalin-based inhibitors containing a single Michael acceptor for targeted inhibition of the NF-κB pathway. Chapter 6 explores small molecule probes that contain a chlorohydrin for covalent inhibition of the androgen receptor N-terminal domain for castration resistant prostate cancer inhibition. Other projects discussed in this thesis relate to the development of cysteine reactive probes for target identification studies. Chapter 4 communicates the synthesis of cysteine reactive probes based on the sesquiterpene lactone natural product parthenolide and their ability to target leukemic stem cells versus healthy bone marrow cells. Chapter 5 presents the synthesis of parthenolide-based alkyne probes for target identification studies in primary human AML cells via pulldown and LC-MS/MS proteomic analysis. Chapter 7 examines the Nicholas reaction and its application toward the attachment of terminal alkynes to complex small molecules.encovalent small moleculesexocyclic methylene butyrolactonehetero-Michael acceptorp65/RelA transcription factorpseudoguaianolide helenalinthiol/cysteine reactive probesThesis or Dissertation