Medicinal and Pharmaceutical Chemistry Commons^™

Delineating The Biosynthesis Of Capuramycin-Type Antibiotics, Ashley L. Biecker

Theses and Dissertations--Pharmacy

New antibiotic scaffolds with novel drug targets are needed to combat the rise of drug-resistant, infectious microorganisms. The bacterial translocase I is a ubiquitous enzyme in the peptidoglycan biosynthetic pathway that has yet to be targeted by clinically used antibiotics. It catalyzes the transfer of N-acetylmuramoyl-pentapeptide to undecaprenylphosphate in order to generate lipid I during cell wall biosynthesis. A screening of bacterial translocase I inhibitors led to the discovery of the novel compound capuramycin and its analogues: A-500359s, A-503083s, and A-102395, produced by various species of actinomycetes. The capuramycins show potent activity against the bacterial translocase I with IC50s …

Novel Small Molecule Antifungals For Invasive Fungal Infections, Emily Dennis

Theses and Dissertations--Pharmacy

Human fungal pathogens cause a range of diseases from benign skin conditions (i.e., ringworm) to thrush, mucosal membrane infections, and life-threatening systemic infections including bloodstream infections (i.e., aspergillosis and candidiasis) and Cryptococcal meningitis. These systemic infections occur most often in immunocompromised individuals and have high mortality rates. Current antifungal agents used in the clinic belong to three main classes: the polyenes (e.g., amphotericin B (AmB)), the echinocandins (e.g., caspofungin (CFG)), and the azoles (e.g., fluconazole (FLC)). In addition, the antimetabolite pyrimidine analogue flucytosine is used in combination with AmB. The …

Correlating The Physicochemical Properties Of Magnesium Stearate With Tablet Dissolution And Lubrication, Julie L. Calahan

Theses and Dissertations--Pharmacy

Magnesium stearate (MgSt) is the most commonly used pharmaceutical excipient and is present in over half the tablet formulations on the market. In spite of its popularity as an effective lubricant, it has been repeatedly recognized that there is significant variability between MgSt samples, which can cause inconsistent lubrication between batches of MgSt. The hypothesis of this research is that the batch-to-batch variability in tablet lubrication and dissolution observed in tablet formulations containing different MgSt samples can be correlated with differences in MgSt physicochemical properties (fatty acid salt composition, crystal hydrate form, particle size and surface area). Developing correlations between …

Toward An Enzyme-Coupled, Bioorthogonal Platform For Methyltransferases: Probing The Specificity Of Methionine Adenosyltransferases, Tyler D. Huber

Theses and Dissertations--Pharmacy

Methyl group transfer from S-adenosyl-l-methionine (AdoMet) to various substrates including DNA, proteins, and natural products (NPs), is accomplished by methyltransferases (MTs). Analogs of AdoMet, bearing an alternative S-alkyl group can be exploited, in the context of an array of wild-type MT-catalyzed reactions, to differentially alkylate DNA, proteins, and NPs. This technology provides a means to elucidate MT targets by the MT-mediated installation of chemoselective handles from AdoMet analogs to biologically relevant molecules and affords researchers a fresh route to diversify NP scaffolds by permitting the differential alkylation of chemical sites vulnerable to NP MTs that are unreactive to …

The Development Of Novel Proteasome Inhibitors For The Treatment Of Multiple Myeloma And Alzheimer’S Disease, Min Jae Lee

Theses and Dissertations--Pharmacy

Over a decade, proteasome inhibitors (PIs), bortezomib, carfilzomib (Cfz) and ixazomib, have contributed to a significant improvement in the overall survival for multiple myeloma (MM) patients. However, the response rate of PI was fairly low, leaving a huge gap in MM patient care. Given this, mechanistic understanding of PI resistance is crucial towards developing new therapeutic strategies for refractory/relapsed MM patients.

In this dissertation work, we found H727 human bronchial carcinoid cells are inherently resistant to Cfz, yet susceptible to other PIs and inhibitors targeting upstream components of the ubiquitin-proteasome system (UPS). It indicated H727 cells may serve as a …

Computational Modeling Guided Discovery Of Novel Inhibitors Of Mpges-1 And Butyrylcholinesterase As Drug Candidates, Shuo Zhou

Theses and Dissertations--Pharmacy

Ever since the advent of computer-aided drug design (CADD), in silico simulation methods have greatly accelerated the drug discovery process and lead to the discovery of numerous drug candidates. With the exponential growth of computational power, we nowadays simulate biologic systems at a scale unimaginable a decade ago and thus provides perspectives for drug design. In this dissertation research, combining in silico simulation methods like molecular docking and molecular dynamics (MD) simulation with organic synthesis, in vitro/in vivo experiments and clinical data mining, we developed new drug discovery strategies. These strategies were applied in our drug discovery projects and led …

Discovery Of New Antimicrobial Options And Evaluation Of Aminoglycoside Resistance Enzyme-Associated Resistance Epidemic, Selina Y. L. Holbrook

Theses and Dissertations--Pharmacy

The extensive and sometimes incorrect and noncompliant use of various types of antimicrobial agents has accelerated the development of antimicrobial resistance (AMR). In fact, AMR has become one of the greatest global threat to human health in this era. The broad-spectrum antibiotics aminoglycosides (AGs) display excellent potency against most Gram-negative bacteria, mycobacteria, and some Gram-positive bacteria, such as Staphylococcus aureus. The AG antibiotics amikacin, gentamicin, kanamycin, and tobramycin are still commonly prescribed in the U.S.A. for the treatment of serious infections. Unfortunately, bacteria evolve to acquire resistance to AGs via four different mechanisms: i) changing in membrane permeability to …

The Development Of Novel Non-Peptide Proteasome Inhibitors For The Treatment Of Solid Tumors, Zachary C. Miller

Theses and Dissertations--Pharmacy

The proteasome is a large protein complex which is responsible for the majority of protein degradation in eukaryotes. Following FDA approval of the first proteasome inhibitor bortezomib for the treatment of multiple myeloma (MM) in 2003, there has been an increasing awareness of the significant therapeutic potential of proteasome inhibitors in the treatment of cancer. As of 2017, three proteasome inhibitors are approved for the treatment of MM but in clinical trials with patients bearing solid tumors these existing proteasome inhibitors have demonstrated poor results. Notably, all three FDA-approved proteasome inhibitors rely on the combination a peptide backbone and reactive …

Synthesis And Biological Evaluation Of Novel Drug Candidates To Address Drug Resistance In Tuberculosis And Fungal Diseases, Huy Ngo

Theses and Dissertations--Pharmacy

Tuberculosis (TB) and fungal infections are two of the most lethal infectious diseases worldwide due to the emergence of drug-resistant Mycobacterium tuberculosis (Mtb) and fungal strains that can resist the most potent antimicrobial drugs currently employed. Due to the rise of these drug resistant strains, effective treatment options for these two infections are limited. This dissertation aims at exploring novel drug scaffolds to help combat drug resistance in TB and fungal infections.

TB caused by the pathogenic Mtb is, alongside with human immunodeficiency virus acquired immunodeficiency virus (HIV), the deadliest infectious disease worldwide with approximately 2-3 billion people …

Chemoenzymatic Studies To Enhance The Chemical Space Of Natural Products, Jhong-Min Chen

Theses and Dissertations--Pharmacy

Natural products provide some of the most potent anticancer agents and offer a template for new drug design or improvement with the advantage of an enormous chemical space. The overall goal of this thesis research is to enhance the chemical space of two natural products in order to generate novel drugs with better in vivo bioactivities than the original natural products.

Polycarcin V (PV) is a gilvocarcin-type antitumor agent with similar structure and comparable bioactivity with the principle compound of this group, gilvocarcin V (GV). Modest modifications of the polyketide-derived tetracyclic core of GV had been accomplished, but the most …

Design, Synthesis, And Pharmacological Evaluation Of Three Series Of Lobelane Analogs As Inhibitors Of The Vesicular Monoamine Transporter (Vmat2), John P. Culver

Theses and Dissertations--Pharmacy

Methamphetamine (METH) abuse is a serious problem in the United States and worldwide. The reward experienced by METH users is due to the increase in extracellular dopamine (DA) concentrations caused by an interaction between METH and the DA transporter (DAT) as well as the Vesicular Monoamine Transporter-2 (VMAT2). The reward felt by users of METH leads to further use of the drug and subsequent abuse. The current project examined the ability of three novel series of lobelane analogs to interact with a binding site on the Vesicular Monoamine Transporter-2 (VMAT2) in an attempt to inhibit the effects of METH. Lobelane …

Quantification Of Factors Governing Drug Release Kinetics From Nanoparticles: A Combined Experimental And Mechanistic Modeling Approach, Kyle Daniel Fugit

Theses and Dissertations--Pharmacy

Advancements in nanoparticle drug delivery of anticancer agents require mathematical models capable of predicting in vivo formulation performance from in vitro characterization studies. Such models must identify and incorporate the physicochemical properties of the therapeutic agent and nanoparticle driving in vivo drug release. This work identifies these factors for two nanoparticle formulations of anticancer agents using an approach which develops mechanistic mathematical models in conjunction with experimental studies.

A non-sink ultrafiltration method was developed to monitor liposomal release kinetics of the anticancer agent topotecan. Mathematical modeling allowed simultaneous determination of drug permeability and interfacial binding to the bilayer from release …

Investigating Key Post-Pks Enzymes From Gilvocarcin Biosynthetic Pathway, Nidhi Tibrewal

Theses and Dissertations--Pharmacy

Gilvocarcin V (GV) belongs to the angucycline class of antibiotics that possesses remarkable anticancer and antibacterial activities with low toxicity. Gilvocarcin exhibits its light induced anticancer activity by mediating crosslinking between DNA and histone H3. When photo-activated by near-UV light, the C8 vinyl group forms a [2+2] cycloadduct with thymine residues of double stranded DNA. _D-fucofuranose is considered essential for histone H3 interactions. However, the poor water solubility has rendered it difficult to develop gilvocarcin as a drug. We aim to design novel gilvocarcin analogues with improved pharmaceutical properties through chemo-enzymatic synthesis and mutasynthesis. Previous studies have characterized many …