Heterocyclic Compounds Commons^™

Total Synthesis Of The Marine Cytotoxic Mansouramycin And Derivatives, Aditya Dantu, Gabriella L. Madrigal, Neel Gondi, David Osazee, Ahmad Amro, Whard Alsabbagh, Shizue Mito

Research Colloquium

Purpose: Isoquinolinequinones are a group of organic compounds which are composed of an isoquinoline fused to a quinone ring. This class of molecules is known to exhibit a wide variety of biological activities, including cytotoxic and antitumor properties. Among the many families of isoquinolinequinones are the Caulibugulones and Mansouramycins, which exhibit anticancer properties and are thus desirable subjects for cancer-related research. They are obtained by isolation from marine bryozoan Caulibugula intermis and marine Streptomyces sp respectively, however these compounds are difficult to extract. Thus, organic synthesis is being explored as a method of obtaining them; this project focuses on the …

Advances In Indole Chemistry: Regiodivergent Annulations And Bridged Azacycle Synthesis, Zachary Tihomir Protich

Dartmouth College Ph.D Dissertations

An important aspect for the research and development of new drug therapies is the ability to use modular synthetic methods to rapidly access structurally diverse drug-like building blocks. Nitrogen-containing heterocycles represent one of the most prevalent structural motifs found in pharmaceutical agents and biologically active natural products. However, despite their ubiquity, existing methods for accessing these structures often remain limited in scope, efficiency, and structural diversity, particularly when targeting densely functionalized or sterically demanding scaffolds from simple starting materials.

To address this problem, the research described in this dissertation focuses on the design and development of (3+2) annulation reactions for …

Unplanned Hospitalization Among Advanced Prostate Cancer Patients By Diabetes Status: A Population-Based Study, Amy L. Shaver, Krupa Gandhi, Scott W. Keith, Nikita Nikita, Christopher C. Yang, Felix J. Kim, Hushan Yang, William K. Kelly, Stephen J. Freedland, Grace Lu-Yao

Kimmel Cancer Center Faculty Papers

BACKGROUND: Older adults with advanced prostate cancer and type 2 diabetes mellitus are underrepresented in trials of androgen receptor pathway inhibitors. This study examined changes in unplanned hospitalization rates in patients receiving androgen receptor pathway inhibitors by type 2 diabetes mellitus status and assessed if unplanned hospitalization varies according to androgen receptor pathway inhibitors.

METHODS: This population-based study of advanced prostate cancer patients aged older than 66 years used Surveillance, Epidemiology, and End Results-Medicare data. Prepost androgen receptor pathway inhibitor initiation changes and androgen receptor pathway inhibitor differences in unplanned hospitalization rates were estimated by adjusted incidence rate ratio with …

Novel Piperidone And Bispidine Derivatives: A New Approach In Cancer Therapy, Lereen Khaled Youssry

Theses and Dissertations

Cancer remains the second leading cause of death worldwide. As a result, scientists have been trying to find novel therapeutic approaches that target specific metabolic pathways selective to tumor cells. In this study, two novel piperidone and bispidine derivatives, organic molecules that target polyamine metabolism, were synthesized, and their potential cytotoxic, antioxidant and anti-inflammatory effects were investigated. Polyamines are naturally occurring metabolites that were reported to be in excess at cancer cells and were accounted for tumor proliferation, invasion and metastasis. Accordingly, the novel piperidone and bispidine derivatives were expected to disrupt tumor growth and progression via up-regulation of key …

Synthesis Of Medicinally Privileged Spiro-Β-Lactams, Debasish Bandyopadhyay, Reinaldo Mendes, Subhash C. Chauhan

Research Symposium

Background: Four-membered cyclic amide, commonly known as β-lactam, has been playing a crucial role in drug discovery research since its discovery by Alexander Fleming in 1928 from Penicillium notatum. The β-lactam antibiotics are broadly effective against several bacterial infections through acylating the transpeptidase involved in cross-linking peptides to form peptidoglycan or periplasmic murein, which is a fundamental constituent of the bacterial cell wall for both the gram-positive (ten or more layers) and gram-negative (one or two layers) bacteria. Although for more than eight decades, β-lactams have been recognized as antibiotics, later, other medicinal activities of β-lactam derivatives have been …

Design, Synthesis, And Nmr-Guided Characterization Of A Targeted Covalent Inhibitor-Like Molecule Against Ivyp1 From P. Aeruginosa, Samuel Taylor Moore

Master's Theses

Multi-drug resistance poses a serious threat to future generations and historical antibiotic pipelines; consequently, the medical and economic burdens associated with treating multidrug-resistant bacteria are substantiated. In this context, P. aeruginosa (PA) emerges as one of the most significant healthcare challenges, being a leading cause of resistance-associated mortality worldwide. Despite modern efforts to combat these poor outcomes, drug-resistant cases continue to rise, and the need for novel antibiotic treatment is apparent. To this end, we investigated relevant resistance mechanisms and past antibiotic targets within PA, and in doing so, we identified relationships between peptidoglycan biology and a periplasmic protein, Inhibitor …

Synthesis Of Photocleavable Molecules For Neurological Applications, Nishal Madujith Egodawaththa Arachchilage Don

Theses and Dissertations

In recent biomedical research, the precise control of molecular dynamics through light activation has emerged as a powerful tool, particularly in the field of neurobiology. This approach involves the use of photocleavable cages or photoprotective groups (PPGs) that are chemically tethered to biologically active molecules such as neurotransmitters or calcium chelators. These cages remain inert until exposed to specific wavelengths of light, typically in the visible range, triggering the release of the active compound with high spatiotemporal precision.

For neurotransmitter systems, such as glutamate (Glu), which plays a critical role in synaptic transmission and memory formation, researchers have developed novel …

Advancing Small Molecule Therapies For Myotonic Dystrophy Type 1, Sawyer M. Hicks

Electronic Theses & Dissertations (2024 - present)

Myotonic dystrophy type 1 (DM1) is a multisystemic disorder caused by the expression of expanded CUG (CUG^exp) repeat RNA from the myotonic dystrophy protein kinase (DMPK) gene. This CUG^exp repeat RNA’s gain-of-function mechanism leads to the sequestration of muscleblind-like (MBNL) proteins, resulting in widespread alternative splicing dysregulation across tissues. Despite significant research, there are currently no approved therapeutics targeting the underlying causes of DM1. This dissertation explores the development and optimization of a novel class of small molecules, Modified Polycyclic Compounds (MPCs), designed to address splicing dysregulation in DM1. MPCs were designed from previously published …

Synthesis Of Selenotryptophan For Protein Elucidation, James P. Reiselman

[Archive] Belmont University Research Symposium (BURS)

Through complex intermolecular and intramolecular forces, proteins conformationally change to form complex 3-d geometry that carries out biochemical processes and mapping their structures is becoming a field of interest in the biological community. Techniques for modeling protein’s structure typically follow the path of X-ray crystallography, which has an intrinsic phase problem that can make reading the electron density map they produce very difficult. This can be mitigated by appending a heavy-atom containing amino acid analogue into a crystal sample of the protein being studied. A selenium containing tryptophan analogue will be synthesized to be appended into proteins as a chemical …

Fluorometric Characterization Of A Methylene Blue Derivative Sensitive To Reactive Oxygen Species (Ros), Matthew Weeks

Honors Theses

Methylene blue (MB) has many uses within both microbiology and pharmacology. MB can treat disorders such as methemoglobinemia, malaria, Alzheimer’s disease, and certain forms of cancer. MB is also useful for molecular imaging due to its off-on fluorescent capabilities. MB derivatives with a urea bond at the 10-N position have been cleavable by triggers such as light. However, I was interested in sensitivity to reactive oxygen species (ROS). In this study, I wanted to determine if the MB derivative MB-EA exhibited sensitivity to ROS. MB-EA was exposed to varying concentrations of hydrogen peroxide and MB release was measured. I concluded …

Synthesis Of Oxadeazoles With Electron Withdrawing Groups And The Analysis Of Product Yield With Bond Length, Elizabeth Ann Hall Peters

Undergraduate Honors Thesis Projects

2,5-disubstituted 1,3,4-oxadiazoles are a class of organic compound that are widely used and successful in pharmaceutical chemistry because they demonstrate strong biological activity. They are part of a larger class of compound called heterocycles, which make up most pharmaceutical drugs today. When synthesizing the compounds, higher yield means higher reactivity of the compound, and this is important for pharmaceuticals that need to have a strong biological activity. Per past studies, electron withdrawing groups on the compound allow higher, product yields. Along with electron withdrawing group addition, the bond length from electron withdrawing group and its corresponding carbon is analyzed to …

A Diversity-Oriented Synthesis Approach To Functionalized Azaheterocycles Using Cyclic Alpha-Halo Eneformamides, Spencer A. Langevin

All Master's Theses

Functionalized piperidines, azepanes, azamacrocycles, morpholines, and thiomorpholines are common structural motifs found in a wide range of pharmaceuticals such as carmegliptine, levofloxacin, thioridazine, claviciptic acid, and azithomycin. As a result, there is a strong desire to construct highly functionalized nitrogen-bearing ring scaffolds in order to construct a wide range of drug possibilities. There are several non-modular and step-uneconomical synthetic methods used in the construction of these aforementioned motifs such as ring closing metathesis, ring expansions, and intramolecular reductive amination. In this research, we present a step-economical, cost-effective, scalable, and diversity-oriented synthesis approach to highly functionalized N-heterocycles through the intermediacy of …

Chemoselective And Stereoselective Exploration Of The Chemical Reactivity Space Of Castagnoli-Cushman-Derived Allylic Lactamoyl Esters: Application To The Synthesis Of Aza-Polycyclic Architectures, Brandon Joseph Mansker

All Master's Theses

The synthesis and evaluation of structure-activity relationships of saturated nitrogen heterocycles is the focal point of various pharmaceutical companies thanks to the high biological activity of previously isolated azacycles. Here, we describe an operationally simple and highly efficient approach to macrocyclic lactams bearing vicinal stereocenters and a challenging cycloalkyne motif. The outcomes are achieved through a novel [4 + 2] cycloaddition reaction between an N-iodoarylated-1,3-azadiene and cyclic anhydrides, followed by interception of the cycloadducts in cross-coupling manifolds (e.g., Sonogashira coupling) and concomitant lithiation-cyclization of the tethered alkyne. An unprecedented example of a hydroamino alkylation that is transition …

Target-Directed Biosynthetic Evolution: Redirecting Plant Evolution To Genomically Optimize A Plant’S Pharmacological Profile, Dustin Paul Brown

Theses and Dissertations--Neuroscience

The dissertation describes a novel method for plant drug discovery based on mutation and selection of plant cells. Despite the industry focus on chemical synthesis, plants remain a source of potent and complex bioactive metabolites. Many of these have evolved as defensive compounds targeted on key proteins in the CNS of herbivorous insects, for example the insect dopamine transporter (DAT). Because of homology with the human DAT protein some of these metabolites have high abuse potential, but others may be valuable in treating drug dependence. This dissertation redirects the evolution of a native Lobelia species toward metabolites with greater activity …