Organic Chemicals Commons^™

Studies Towards Chemical Synthesis Of Homogeneous Prion Glycoprotein, Baotong Tian

Electronic Theses & Dissertations (2024 - present)

Prion diseases are fatal neurodegenerative disorders initiated by conformational misfolding of the prion protein (PrP), which generates pathogenic conformers that propagate via templated conversion and accumulate as aggregates. Glycosylation can modulate the PrP folding energy landscape, thereby biasing folding trajectories and the distribution of resulting conformational states. Bank vole PrP contains two N-linked glycosylation sites, and disentangling the contributions of site occupancy versus glycan structure requires homogeneous, site-defined glycoforms. In contrast, biosynthetic expression typically produces heterogeneous glycoform ensembles due to multistep Golgi processing, precluding independent control of glycan identity at each site. Here we report a chemical synthesis strategy of …

Computationally Assessing The Specificity Of Receptor Tyrosine Kinase Inhibitors, Htoo Say

Theses/Capstones/Creative Projects

Receptor tyrosine kinases (RTKs) are vital to cell signaling processes such as growth, survival, and differentiation. Dysregulation through mutation or overexpression often contributes to cancer, making RTKs key therapeutic targets for tyrosine kinase inhibitors (TKIs). However, the low specificity of many TKIs leads to off-target effects. This project uses molecular docking to evaluate the binding affinities and selectivity of FDA-approved TKIs across 18 RTK subtypes. The dockings conducted revealed significant variability in binding affinities, with Sorafenib exhibiting strong specificity for EphB2 (-7.6 kcal/mol) and poor compatibility with EphA7 and ErbB4 (-3.0 kcal/mol). These findings underscore the role of specific molecular …

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 …

Nanoparticles For Applications In Specific Diagnostics And Precision Medicine, Naxhije Berisha

Dissertations, Theses, and Capstone Projects

Heterogeneity is common in the expression of cancer and treatment response. Precision medicine enables healthcare providers to tailor medical care to an individual's distinct genetic and environmental makeup. This customization has the potential to result in more efficient treatments while minimizing side effects. We believe that by studying the interface of nanotechnology and cancer medicine we can elucidate innovative solutions that address the challenges of disease heterogeneity. This includes advancements in drug delivery, formulations development, and diagnostic sensing. We highlight three studies that use nanotechnology for applications in precision medicine. In Chapter 2, we highlight design optimization of drug formulations …

Second Generation Phenyloxadiazolyl Methyl Sulfones For Thiol-Specific Bioconjugations, Guillaume Dewaele-Le Roi

Dissertations, Theses, and Capstone Projects

The role of antibody-based molecular agents for diagnosis and therapy of cancer has expanded significantly over the past decades. However, most of these constructs are synthesized using traditional bioconjugation methods based on the random ligations between the molecular cargo and lysine residues within the protein. These non-specific approaches can create poorly defined conjugates with suboptimal immunoreactivity and in vivo performance while Site-specific approaches to antibody bioconjugation based on ligations between maleimides and free cysteine residues have long stood as attractive alternatives. Yet the inherent instability of the thiol-maleimide linkage has fueled the search for new, more stable thiol-reactive prosthetic groups. …

Identification Of Novel Biosynthetic Gene Clusters Encoding For Polyketide/Nrps-Producing Chemotherapeutic Compounds From Marine-Derived Streptomyces Hygroscopicus From A Marine Sanctuary, Hannah Ruth Flaherty

Honors Theses and Capstones

Nearly one out of six deaths in 2020, around ten million people, were caused by cancer, making it a leading cause of death worldwide (WHO, 2022). This major public health issue, in addition to the rise of multidrug-resistant (MDR) pathogens, provides a high demand for the discovery of new pharmaceutical drugs to be used clinically to treat these conditions. The Streptomyces genus accounts to produce 39% of all microbial metabolites currently approved for human health, indicating its potential as an important species to study for antimicrobial and anticancer agents. The long linear genome of Streptomyces contains specialized sequences known as …

Isoprenylation Inhibition Suppresses Fcεri-Mediated Mast Cell Function And Allergic Inflammation, Aditya Kotha, Jordan M. Dailey, Aslamuzzaman Kazi, Said Sebti, John J. Ryan

Undergraduate Research Posters

Allergic disease is driven by cell signaling cascades that activate immune cells. One key player is mast cells, which is activated by IgE antibodies signaling through the high affinity IgE receptor, FceRI. Therefore, targeting FceRI-mediated cascades can offer for novel treatments for allergic disease. Statins have been demonstrated to reduce the severity of asthma, a common allergic airway disease. Statins are an FDA approved class of drugs with the intended purpose of lowering blood cholesterol. We previously found that while statins inhibit mast cell function in allergic disease, these anti-inflammatory effects vary widely amongst differing mouse strains and human donors, …

Development Of A Chemical Biology Approach To Uncover The Influence Of Sequence Variations On Ces1 Activity In Live Cells, Samuel James Knebel

Masters Theses

Drug metabolism is the biochemical process of modifying drugs to detoxify and remove them through enzymatic transformations. These biotransformation’s occur primarily in the liver and are critical to understanding how pharmaceutical compounds are chemically altered inside the human body. Human carboxylesterases (CESs) catalyze the hydrolysis of esters, amides, thioesters, and carbamates. CES-mediated hydrolysis plays an important role in the metabolism of many drugs including the first FDA approved antiviral treatment for COVID-19, remdesivir (Veklury), the seizure control medication rufinamide (Banzel), and the flu antiviral drug oseltamivir (Tamiflu). CES activity is known to be influenced by a variety of factors including …

Designing And Synthesizing A Warhead-Fragment Inhibitory Ligand For Ivyp1 Through Fragment-Based Drug Discovery, Samuel Moore

Symposium of Student Scholars

Fragment-based drug discovery (FBDD) is a powerful tool for developing anticancer and antimicrobial agents. Within this, magnetic resonance spectroscopy (NMR) provides a comprehensive qualitative and quantitative approach to screening and validating weak and robust binders with targeted proteins, making NMR among the most attractive strategies in FBDD. Inhibitor of vertebrate lysozyme (Ivyp1) of P. aeruginosa serves as an excellent target because of its active cellular location and implications in clinical prognosis for cystic fibrosis and immunocompromised patients. This study uses current NMR and biophysical techniques to develop a covalent, fragment-linked warhead inhibitor for Ivyp1 through synthetic methods, warhead linking, and …

Bis(Tryptophan) Amphiphiles: Design, Synthesis And Efficacy As Antimicrobial Agents, Michael Mckeever

Dissertations

Amphiphiles play important roles in nature. These molecules contain both hydrophilic and hydrophobic regions, leading to some astonishing properties. The lipid bilayer of the cell membrane is a fascinating organization of amphiphilic phospholipids. Natural and synthetic amphiphiles, such as antimicrobial peptides, interact with the cell membrane. Such interactions can impact transport of molecules across the cell membrane, disrupting cell functions. In this work, a library of tryptophan-containing amphiphiles was synthesized and their antimicrobial properties were explored.

First, a library of bis(tryptophan) amphiphiles was synthesized. Preparation included a coupling reaction of a diamine with tryptophan residues, via their carboxy-termini, at …

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 …

Anatomy And Physiology Preparatory Course Textbook (2nd Edition), Carlos Liachovitzky

Open Educational Resources

The goal of this preparatory textbook is to give students a chance to become familiar with some terms and some basic concepts they will find later on in the Anatomy and Physiology course, especially during the first few weeks of the course.

Organization and functioning of the human organism are generally presented starting from the simplest building blocks, and then moving into levels of increasing complexity. This textbook follows the same presentation. It begins introducing the concept of homeostasis, then covers the chemical level, and later on a basic introduction to cellular level, organ level, and organ system level. This …

Toward The Total Synthesis Of Dragonamide E And Its Potential Medicinal Application Against Leishmaniasis, Nathaniel M. Smith

Chemistry Theses

Leishmaniasis is one of the world’s most neglected tropical diseases, with hundreds of thousands of cases occurring worldwide annually. The disease originates from being infected by protozoa of the Leishmania genus, which are parasites that destroy mammalian cells as part of their life cycle. Currently utilized treatment strategies for leishmaniasis have many disadvantages, warranting the search for a new leishmaniasis treatment.

Cyanobacteria have been discovered to synthesize a wide variety of cytotoxic chemicals as part of their own defense mechanism. One strain of cyanobacteria, Lyngbya majuscula, produces several families of compounds, one of which is known as the “dragonamides”. …

Reeling In New Antibiotics: Synthesis And Antimicrobial Susceptibility Testing Of Zinc-Binding Clavanins From Styela Clava (Sea Squirt), Eduardo Badillo-Colberg

Honors Scholar Theses

Clavanins have been a quite rarely studied antimicrobial peptide (AMP) family. Though the data in the few studies published on the matter and in theoretical experimental data presented by the Wang lab in their peptide library creation [14], in that the members of this family could potentially be quite effective novel antimicrobial candidates. Among those that have been targets of studies, Clavanin A has been at the forefront of this endeavor of finding effective novel antimicrobial peptides[14]. In these aforementioned studies, Clavanin A has been shown to be quite effective against many different bacterial strains, which begs the question as …

Determining The Antibacterial Activity And Mode Of Action Of Tirandamycin, Hailey Bouchard

CMC Senior Theses

Tirandamycin is a small molecule natural product that has been isolated from various species of marine and terrestrial Streptomyces. The natural product has shown antibacterial activity against an array of Gram-positive and Gram-negative bacteria, showing promise as a pharmaceutical drug. Tirandamycin has 14 known derivatives, many of which have been created synthetically. Some of its derivatives are particularly potent against the high-risk bacteria vancomycin-resistant Enterococcus faecium, Staphylococcus aureus, Streptococcus agalactiae, Streptococcus pneumoniae and Escherichia coli. However, the antibacterial potency of these derivatives has not been tested systematically leading to the possibility of discovering more potent …

Identification Of Antibiotic Ge37468a From Pseudonocardia Symbionts Of Trachymyrmex Septentrionalis Ants, Krithika Rao

Scripps Senior Theses

In response to the growing rates of antibiotic resistance in human bacterial pathogens, this study explores the natural products involved in the defensive symbiosis between actinobacteria and fungus-growing ants to uncover new potential antibiotics. This study also seeks to understand the function of natural antibiotics in their ecological contexts, especially those involved in defensive symbioses. Defensive symbiosis can be a beneficial platform for discovering useful antibiotics, because antibiotics in these relationships must be able to selectively inhibit enemies without harming hosts, and are therefore likely more specific and less toxic. Pseudonocardia sp. associated with Trachymyrmex septentrionalis ants demonstrated antibiotic activity …

Design, Synthesis, And Evaluation Of Homochiral Peptides Containing Arginine And Histidine As Molecular Transporters, Naglaa Salem El-Sayed, Taryn Miyake, Amir Nasrolahi Shirazi, Shang Eun Park, Jimmy Clark, Stephani Buchholz, Keykavous Parang, Rakesh Tiwari

Pharmacy Faculty Articles and Research

Linear (HR)n and cyclic [HR]n peptides (n = 4,5) containing alternate arginine and histidine residues were synthesized. The peptides showed 0–15% cytotoxicity at 5–100 μM in human ovarian adenocarcinoma (SK-OV-3) cells while they exhibited 0–12% toxicity in human leukemia cancer cell line (CCRF-CEM). Among all peptides, cyclic [HR]4 peptide was able to improve the delivery of a cell impermeable fluorescence-labeled phosphopeptide by two-fold. Fatty acids of different alkyl chain length were attached at the N-terminal of the linear peptide (HR)4 to improve the molecular transporter property. Addition of fatty acyl chains was expected to help with the permeation of the …

Efficient Intracellular Delivery Of Cell-Impermeable Cargo Molecules By Peptides Containing Tryptophan And Histidine, Amir Nasrolahi Shirazi, Saghar Mozaffari, Rinzhin Tshering Sherpa, Rakesh Tiwari, Keykavous Parang

Pharmacy Faculty Articles and Research

We have previously evaluated and reported numerous classes of linear and cyclic peptides containing hydrophobic and hydrophilic segments for intracellular delivery of multiple molecular cargos. Herein, a combination of histidine and tryptophan amino acids were designed and evaluated for their efficiency in intracellular delivery of cell-impermeable phosphopeptides and the anti-HIV drug, emtricitabine. Two new decapeptides, with linear and cyclic natures, both containing alternate tryptophan and histidine residues, were synthesized using Fmoc/tBu solid-phase chemistry. The peptides were characterized and purified by using matrix-assisted laser desorption/ionization (MALDI) spectroscopy and high-performance liquid chromatography (HPLC), respectively. These peptides did not show significant toxicity up …

Site-Selective Modification Of Peptides And Proteins Via Organocatalyzed Henry Reaction, Zilma Pereira Muneeswaran

Seton Hall University Dissertations and Theses (ETDs)

In this research, peptides and protein containing serine on the N-terminus underwent site-selective modification following organocatalyzed bioconjugation that offered an additional functional group. It was shown that transforming the N-terminus serine to an aldehyde allowed site-specific bioconjugation to occur by utilizing the well-known Henry reaction. This method also grants a safer pathway for bioconjugation utilizing “green-chemistry” and biocompatible conditions. Amino acids and amino acid derived organocatalysts were utilized in the Henry reaction resulting in yields of up to 86 % conversion. Promising preliminary results were achieved in this research using peptides and myoglobin as the bioconjugation targets. Further investigation to …

Novel Combination Bmp7 And Hgf Gene Therapy Instigates Selective Myofibroblast Apoptosis And Reduces Corneal Haze In Vivo, Suneel Gupta, Michael K. Fink, Arkasubhra Ghosh, Ratnakar Tripathi, Prashant R. Sinha, Ajay Sharma, Nathan P. Hesemann, Shyam S. Chaurasia, Elizabeth A. Giuliano, Rajiv R. Mohan

Pharmacy Faculty Articles and Research

PURPOSE. We tested the potential of bone morphogenic protein 7 (BMP7) and hepatocyte growth factor (HGF) combination gene therapy to treat preformed corneal fibrosis using established rabbit in vivo and human in vitro models.

METHODS. Eighteen New Zealand White rabbits were used. Corneal fibrosis was produced by alkali injury. Twenty-four hours after scar formation, cornea received topically either balanced salt solution (BSS; n ¼ 6), polyethylenimine-conjugated gold nanoparticle (PEI2-GNP)-naked plasmid (n ¼ 6) or PEI2-GNP plasmids expressing BMP7 and HGF genes (n ¼ 6). Donor human corneas were used to obtain primary human corneal fibroblasts and myofibroblasts for mechanistic studies. …

Difatty Acyl-Conjugated Linear And Cyclic Peptides For Sirna Delivery, Hung Do, Meenakshi Sharma, Naglaa Salem El-Sayed, Parvin Mahdipoor, Emira Bousoik, Keykavous Parang, Hamidreza Montazeri Aliabadi

Pharmacy Faculty Articles and Research

A number of amphiphilic difatty acyl linear and cyclic R5K2 peptide conjugates were synthesized by solid-phase peptide methods to enhance the interaction with the hydrophobic cellular phospholipid bilayer and to improve siRNA delivery and silencing. Binding to siRNA molecules was significantly less for the cyclic peptide conjugates. A gradual decrease was observed in the particle size of the complexes with increasing peptide/siRNA ratio for most of the synthesized peptides, suggesting the complex formation. Most of the complexes showed a particle size of less than 200 nm, which is considered an appropriate size for in vitro siRNA delivery. A number of …

Diversity Oriented Synthesis, Characterization And Anti-Cancer Activity Of Killer Peptide Nucleolipid Bioconjugates, Niki K. Rana

Seton Hall University Dissertations and Theses (ETDs)

The killer peptide sequence D-(KLAKLAK)₂ has been originally designed and developed as an antibacterial agent. Despite having excellent cytotoxicity towards bacteria, this sequence maintains low cell cytotoxity in malignant mammalian cell types such as cancer. The chemical basis for its selectivity has been attributed to its poly(cationic) amphiphilic nature, which facilitates cell permeability across the negatively charged bacterial membrane, but with limited permeability across the zwitterionic membrane of mammalian cells. The positively charged D-(KLAKLAK)₂ sequence has been found to accumulate on the surface of the mitochondria causing dissipation of the negatively charged mitochondrial membrane potential. This charge disruption …

Partial Amino Acid Sequence Of Lipid Transfer Protein From Fennel (Foeniculum Vulgare) Seeds, Hasan Al-Shiyab, Caroline Aziz

Student Scholar Symposium Abstracts and Posters

Fennel (Foeniculum vulgare) is a biennial Egyptian medicinal plant with an aromatic odor that belongs to the family Apiaceae (Umbelliferae). Fennel seeds are commonly used in traditional medicine, as they are known to have anti-inflammatory, anti-fungal and anti-cancerous activities. The major constituents of the fennel plant are sugars, minerals, essential fatty acids, proteins and fibers. Although, there are numerous studies on the medicinal properties of essential oils of the fennel seeds, but there is limited data reported on the proteins and peptides. The aims of this project are to fully characterize the primary structure of proteins and to determine their …

Assembly Of Nucleic Acid-Based Nanoparticles By Gas-Liquid Segmented Flow Microfluidics, Matthew L. Capek, Ross Verheul, David H. Thompson

The Summer Undergraduate Research Fellowship (SURF) Symposium

The development of novel and efficient mixing methods is important for optimizing the efficiency of many biological and chemical processes. Tuning the physical and performance properties of nucleic acid-based nanoparticles is one such example known to be strongly affected by mixing efficiency. The characteristics of DNA nanoparticles (such as size, polydispersity, ζ-potential, and gel shift) are important to ensure their therapeutic potency, and new methods to optimize these characteristics are of significant importance to achieve the highest efficacy. In the present study, a simple segmented flow microfluidics system has been developed to augment mixing of pDNA/bPEI nanoparticles. This DNA and …

Human Anatomy And Physiology Preparatory Course (1st Edition), Carlos Liachovitzky

Open Educational Resources

The overall purpose of this preparatory course textbook is to help students familiarize with some terms and some basic concepts they will find later in the Human Anatomy and Physiology I course.

The organization and functioning of the human organism generally is discussed in terms of different levels of increasing complexity, from the smallest building blocks to the entire body. This Anatomy and Physiology preparatory course covers the foundations on the chemical level, and a basic introduction to cellular level, organ level, and organ system levels. There is also an introduction to homeostasis at the beginning.

Endothelial And Smooth Muscle-Dependent Vascular Reactivity In Immature Arterialized Collateral Capillaries, Caitlin Koeroghlian

Biomedical Engineering

Peripheral arterial occlusive disease (PAOD) occurs due to the build up of atherosclerotic plaque and reduces blood flow to cause chronic ischemia. Patients with PAOD may experience intermittent claudication, or the pain in limb skeletal muscles due to a decease in blood flow. Collateral arteries can act as a natural bypass and improve blood flow to hypoxic tissue by creating an alternate route for blood to flow, but not all patients with PAOD have pre-existing collateral networks. Animal studies indicate that tissues without pre-existing collateral networks can form de novo collaterals from capillaries following occlusion of a feed artery. Unfortunately, …

Synthesis And Stability Studies Of Prodrugs And Codrugs Of Naltrexone And 6-Β-Naltrexol, Joshua A. Eldridge

Theses and Dissertations--Pharmacy

The present study was divided between two different drug delivery goals, each involving naltrexone (NTX) or its active metabolite, 6-β-naltrexol (NTXOL). First, amino acid esters of NTX and NTXOL were prepared in order to test their candidacy for microneedle-enhanced transdermal delivery. Second, a 3-O-(-)-cytisine-naltrexone (CYT-NTX) codrug was prepared for screening as a potential oral delivery form of NTX and (-)-cytisine (CYT). The amino acid prodrugs were intended for the treatment of alcohol abuse, while the codrug was designed as a single agent for the treatment of alcoholism and tobacco-dependency co-morbidities. One hypothesis of this work was that prodrugs …

Synthesis And Biochemical Activities Of Antiproliferative Amino Acid And Phosphate Derivatives Of Microtubule-Disrupting Beta-Lactam Combretastatins, Niamh M. O'Boyle, Lisa M. Greene, Niall O. Keely, Shu Wang, Tadhg S. Cotter, Daniela M. Zisterer, Mary J. Meegan

Articles

The synthesis and biochemical activities of novel water-soluble β-lactam analogues of combretastatin A-4 are described. The first series of compounds investigated, β-lactam phosphate esters 7a, 8a and 9a, exhibited potent antiproliferative activity and caused microtubule disruption in human breast carcinoma-derived MCF-7 cells. They did not inhibit tubulin polymerisation in vitro, indicating that biotransformation was necessary for their antiproliferative and tubulin binding effects in MCF-7 cells. The second series of compounds, β-lactam amino acid amides (including 10k and 11l) displayed potent antiproliferative activity in MCF-7 cells, disrupted microtubules in MCF-7 cells and also inhibited the polymerisation of …

Common And Distinct Mechanisms Of Different Redox-Active Carcinogens Involved In The Transformation Of Mouse Jb6p+ Cells, Sun Yang, Bobbye J. Misner, Rita Chiu, Frank L. Meyskens Jr.

Pharmacy Faculty Articles and Research

We transformed JB6P+ cells with prolonged intermittent low-dose UVB radiation or prolonged exposure to low-dose H2O2 or CdCl2. Stable transformation was confirmed by an anchorage-independence assay. The JB6P+ transformants formed more colonies (∼six folds) in soft agar as compared to their JB6P+ parent cells and were associated with increased intracellular reactive oxygen species (ROS) levels. Activating protein-1 (AP-1) is a family of transcription factors that are rapidly activated by elevated intracellular ROS levels, and their composition is important in the process of cellular transformation and/or tumor progression. To investigate if carcinogenesis induced by distinct carcinogens was via similar molecular mechanisms …

The Primary Structure Of Hemoglobins Of The Adult Jaguar (Panthera Onco, Carnivora), Aftab Ahmed, Meeno Jahan, Zafar H. Zaidi, Gerhard Braunitzer, Reinhard Göltenboth

Pharmacy Faculty Articles and Research

The primary structure of the hemoglobins from Jaguar (Panthera onco) are presented. Electrophoretic separations without and with a dissociating agent revealed the presence of two hemoglobin components, OL2ß\ and a2 02. The separation of the hemoglobin components was achieved by ion-exchange chromatography. The globin chains were separated by ion-exchange chromatography and also by reversed phase HPLC. The amino-acid sequences of the native chains and peptides were determined by liquid-phase and gas-phase sequencing. N-Acetylserine was detected by FAB-mass spectroscopy as N-terminal group of the ßl chain. The sequences are compared with that of human hemoglobin (Hb A).