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Articles 1 - 30 of 911

Full-Text Articles in Medicinal-Pharmaceutical Chemistry

Donnan Potential Across The Outer Membrane Of Gram-Negative Bacteria And Its Effect On The Permeability Of Antibiotics, Olaniyi Alegun, Ankit Pandeya, Jian Cui, Isoiza Ojo, Yinan Wei Jun 2021

Donnan Potential Across The Outer Membrane Of Gram-Negative Bacteria And Its Effect On The Permeability Of Antibiotics, Olaniyi Alegun, Ankit Pandeya, Jian Cui, Isoiza Ojo, Yinan Wei

Chemistry Faculty Publications

The cell envelope structure of Gram-negative bacteria is unique, composed of two lipid bilayer membranes and an aqueous periplasmic space sandwiched in between. The outer membrane constitutes an extra barrier to limit the exchange of molecules between the cells and the exterior environment. Donnan potential is a membrane potential across the outer membrane, resulted from the selective permeability of the membrane, which plays a pivotal role in the permeability of many antibiotics. In this review, we discussed factors that affect the intensity of the Donnan potential, including the osmotic strength and pH of the external media, the osmoregulated periplasmic glucans ...


Synthetic And Biological Studies On Benzazepine Derivatives As Dopamine Receptor Ligands, Rajan Giri Jun 2021

Synthetic And Biological Studies On Benzazepine Derivatives As Dopamine Receptor Ligands, Rajan Giri

Dissertations, Theses, and Capstone Projects

Dopamine (DA) receptors, members of the G-protein coupled receptors (GPCRs) family, are divided in two groups based on their transmembrane structural homology domains: D1R-like (D1R, D5R sub-types) and D2R-like DA receptors (D2R, D3R and D4R sub-types). Disturbances in dopaminergic neurotransmission are associated with several CNS disorders. Hence, DA receptor selective ligands have been sought as pharmacological agents to normalize perturbations in the dopaminergic system. Despite several notable efforts, the discovery of highly selective ligands for dopamine receptor sub-types has proved challenging due to close transmembrane structural similarity, especially between DA receptor sub-types within the same group.

The 1-phenylbenzazepine scaffold is ...


Theranostic Applications Of Sirna Bioconjugates In Cancer Detection And Treatment, Sunil S. Shah May 2021

Theranostic Applications Of Sirna Bioconjugates In Cancer Detection And Treatment, Sunil S. Shah

Seton Hall University Dissertations and Theses (ETDs)

Abstract

The emerging field of RNA nanotechnology has led to rapid advances in the applications of RNA in chemical biology, medicinal chemistry, and biotechnology. At the forefront of its utility is the ability to self-assemble multiple siRNAs into nanostructure formulations capable of targeting selected oncogenes and potentiating the gene therapy of malignant tumors. Self-assembled siRNA integrates multiple siRNAs within a single molecular platform for silencing multiple oncogenic mRNA targets with high precision and efficacy to potentially induce cancer cell apoptosis through the RNA interference (RNAi) pathway. Furthermore, the conjugation of siRNA self-assemblies with bio-active probes results in multi-functional theranostic (therapy ...


Structure Elucidation Of The Elusive Enzyme I Monomer Reveals The Molecular Mechanisms Linking Oligomerization And Enzymatic Activity, Trang T. Nguyen, Rodolfo Ghirlando, Julien F. Roche, Vincenzo Venditti May 2021

Structure Elucidation Of The Elusive Enzyme I Monomer Reveals The Molecular Mechanisms Linking Oligomerization And Enzymatic Activity, Trang T. Nguyen, Rodolfo Ghirlando, Julien F. Roche, Vincenzo Venditti

Chemistry Publications

Enzyme I (EI) is a phosphotransferase enzyme responsible for converting phosphoenolpyruvate (PEP) into pyruvate. This reaction initiates a five-step phosphorylation cascade in the bacterial phosphotransferase (PTS) transduction pathway. Under physiological conditions, EI exists in an equilibrium between a functional dimer and an inactive monomer. The monomer–dimer equilibrium is a crucial factor regulating EI activity and the phosphorylation state of the overall PTS. Experimental studies of EI’s monomeric state have yet been hampered by the dimer’s high thermodynamic stability, which prevents its characterization by standard structural techniques. In this study, we modified the dimerization domain of EI (EIC ...


Theranostic Nanoparticles Folic Acid-Carbon Dots-Drug(S) For Cancer, Godwin Kweku Babanyinah May 2021

Theranostic Nanoparticles Folic Acid-Carbon Dots-Drug(S) For Cancer, Godwin Kweku Babanyinah

Electronic Theses and Dissertations

This study aims to prepare theranostic nanoparticles (NPs) that are expected to increase cancer diagnostics and therapeutic efficacy. We prepared the NPs constituting carbon dots (CDs) as an imaging agent, folic acid as a targeting agent, doxorubicin (DOX), or gemcitabine (GEM) as chemotherapy agents. The NPs include noncovalent FA-CDs-DOX, covalent CDs-FA-DOX, and covalent FA-CDs-GEM. Through ultraviolet-visible spectroscopy, fluorescence spectroscopy, and Fourier transform-infrared spectroscopy, the fabrication of these NPs was confirmed. It was discovered that the high drug loading efficiency is the noncovalent series while the high drug loading capacity is the covalent series The in-vitro pH-dependent drug release data indicate ...


Sulfur Anions: Comments Upon Structure, Charles A. Kingsbury Mar 2021

Sulfur Anions: Comments Upon Structure, Charles A. Kingsbury

Faculty Publications -- Chemistry Department

This work emphasizes the need for solvent simulation as well as a counterion in calculations concerning anions, although optimization may be difficult. Solvent and counterion both play a large role in conformation of the ion. Part of the reason for the success of sulfur anions in chemical reactions may be the ability of sulfone oxygen(s) to coordinate with the counterion (usually lithium). The “solvent” partially dissociates lithium from the carbanion center.


Using Molecular Dynamics Simulations To Understand Receptor-Complex Communication And Signaling, Hannah Margaret Hoag Feb 2021

Using Molecular Dynamics Simulations To Understand Receptor-Complex Communication And Signaling, Hannah Margaret Hoag

Theses and Dissertations

The overarching purpose of this document is to use Computer-aided drug design and Molecular dynamic simulations to better understand elusive drug-receptor interactions, as well as various types of inter-receptor signaling. Chapter One introduces the theory and importance of Computer-aided drug design and the methodology used in both Chapters Two and Three.

Chapter Two uncovers the relationship between the well-studied ABCB1 transporter and a newly identified drug known as Xanthohumol (XN). XN is compared to a commonly used drug, Doxorubicin (DOX), in this chapter. If the ABCB1 transporter can be properly inhibited, cancer-fighting drugs will be able to stay within the ...


Label‑Free Spectral Imaging To Study Drug Distribution And Metabolism In Single Living Cells, Qamar Alshammari, Rajasekharreddy Pala, Nir Katzir, Surya M. Nauli Feb 2021

Label‑Free Spectral Imaging To Study Drug Distribution And Metabolism In Single Living Cells, Qamar Alshammari, Rajasekharreddy Pala, Nir Katzir, Surya M. Nauli

Pharmacy Faculty Articles and Research

During drug development, evaluation of drug and its metabolite is an essential process to understand drug activity, stability, toxicity and distribution. Liquid chromatography (LC) coupled with mass spectrometry (MS) has become the standard analytical tool for screening and identifying drug metabolites. Unlike LC/MS approach requiring liquifying the biological samples, we showed that spectral imaging (or spectral microscopy) could provide high-resolution images of doxorubicin (dox) and its metabolite doxorubicinol (dox’ol) in single living cells. Using this new method, we performed measurements without destroying the biological samples. We calculated the rate constant of dox translocating from extracellular moiety into the ...


The Mechanism Of Β-N-Methylamino-L-Alanine Inhibition Of Trna Aminoacylation And Its Impact On Misincorporation, Nien-Ching Han, Tammy J. Bullwinkle, Kaeli F. Loeb, Kym F. Faull, Kyle Mohler, Jesse Rinehart, Michael Ibba Jan 2021

The Mechanism Of Β-N-Methylamino-L-Alanine Inhibition Of Trna Aminoacylation And Its Impact On Misincorporation, Nien-Ching Han, Tammy J. Bullwinkle, Kaeli F. Loeb, Kym F. Faull, Kyle Mohler, Jesse Rinehart, Michael Ibba

Biology, Chemistry, and Environmental Sciences Faculty Articles and Research

β-N-methylamino-l-alanine (BMAA) is a nonproteinogenic amino acid that has been associated with neurodegenerative diseases, including amyotrophic lateral sclerosis (ALS) and Alzheimer's disease (AD). BMAA has been found in human protein extracts; however, the mechanism by which it enters the proteome is still unclear. It has been suggested that BMAA is misincorporated at serine codons during protein synthesis, but direct evidence of its cotranslational incorporation is currently lacking. Here, using LC-MS–purified BMAA and several biochemical assays, we sought to determine whether any aminoacyl-tRNA synthetase (aaRS) utilizes BMAA as a substrate for aminoacylation. Despite BMAA's previously predicted ...


Nad(H) Phosphates Mediate Tetramer Assembly Of Human C-Terminal Binding Protein (Ctbp), Jeffry C. Nichols, Celia A. Schiffer, William E. Royer Jan 2021

Nad(H) Phosphates Mediate Tetramer Assembly Of Human C-Terminal Binding Protein (Ctbp), Jeffry C. Nichols, Celia A. Schiffer, William E. Royer

University of Massachusetts Medical School Faculty Publications

C-terminal binding proteins (CtBPs) are co-transcriptional factors that play key roles in cell fate. We have previously shown that NAD(H) promotes the assembly of similar tetramers from either human CtBP1 and CtBP2 and that CtBP2 tetramer destabilizing mutants are defective for oncogenic activity. To assist structure-based design efforts for compounds that disrupt CtBP tetramerization, it is essential to understand how NAD(H) triggers tetramer assembly. Here, we investigate the moieties within NAD(H) that are responsible for triggering tetramer formation. Using multi-angle light scattering (MALS) we show that ADP is able to promote tetramer formation of both CtBP1 and ...


Unique Structural Solution From A Vh3-30 Antibody Targeting The Hemagglutinin Stem Of Influenza A Viruses, Wayne D. Harshbarger, Derrick Deming, Gordon J. Lockbaum, Nattapol Attatippaholkun, Maliwan Kamkaew, Shurong Hou, Mohan Somasundaran, Jennifer P. Wang, Robert W. Finberg, Quan Karen Zhu, Celia A. Schiffer, Wayne A Marasco Jan 2021

Unique Structural Solution From A Vh3-30 Antibody Targeting The Hemagglutinin Stem Of Influenza A Viruses, Wayne D. Harshbarger, Derrick Deming, Gordon J. Lockbaum, Nattapol Attatippaholkun, Maliwan Kamkaew, Shurong Hou, Mohan Somasundaran, Jennifer P. Wang, Robert W. Finberg, Quan Karen Zhu, Celia A. Schiffer, Wayne A Marasco

Schiffer Lab Publications

Broadly neutralizing antibodies (bnAbs) targeting conserved influenza A virus (IAV) hemagglutinin (HA) epitopes can provide valuable information for accelerating universal vaccine designs. Here, we report structural details for heterosubtypic recognition of HA from circulating and emerging IAVs by the human antibody 3I14. Somatic hypermutations play a critical role in shaping the HCDR3, which alone and uniquely among VH3-30 derived antibodies, forms contacts with five sub-pockets within the HA-stem hydrophobic groove. 3I14 light-chain interactions are also key for binding HA and contribute a large buried surface area spanning two HA protomers. Comparison of 3I14 to bnAbs from several defined ...


Crystal Structure Of Sars-Cov-2 Main Protease In Complex With The Non-Covalent Inhibitor Ml188, Gordon J. Lockbaum, Archie C. Reyes, Jeong Min Lee, Ronak Tilvawala, Ellen A. Nalivaika, Akbar Ali, Nese Kurt Yilmaz, Paul R. Thompson, Celia A. Schiffer Jan 2021

Crystal Structure Of Sars-Cov-2 Main Protease In Complex With The Non-Covalent Inhibitor Ml188, Gordon J. Lockbaum, Archie C. Reyes, Jeong Min Lee, Ronak Tilvawala, Ellen A. Nalivaika, Akbar Ali, Nese Kurt Yilmaz, Paul R. Thompson, Celia A. Schiffer

COVID-19 Publications by UMMS Authors

Viral proteases are critical enzymes for the maturation of many human pathogenic viruses and thus are key targets for direct acting antivirals (DAAs). The current viral pandemic caused by SARS-CoV-2 is in dire need of DAAs. The Main protease (M(pro)) is the focus of extensive structure-based drug design efforts which are mostly covalent inhibitors targeting the catalytic cysteine. ML188 is a non-covalent inhibitor designed to target SARS-CoV-1 M(pro), and provides an initial scaffold for the creation of effective pan-coronavirus inhibitors. In the current study, we found that ML188 inhibits SARS-CoV-2 M(pro) at 2.5 microM, which is ...


Synthesis And Cytotoxicity Of Trisubstituted Imidazoles, Venkata Agasthya Kasibotla Jan 2021

Synthesis And Cytotoxicity Of Trisubstituted Imidazoles, Venkata Agasthya Kasibotla

Theses and Dissertations

Aza heterocyclic compounds are an important class of organic compounds that play a major role in medicinal chemistry. Majority of the heterocyclic motifs such as imidazoles, triazoles, piperazines etc. act as building blocks for synthesizing active pharmaceutical ingredients. Several pharmaceutical drugs include these motifs due to their varying physicochemical properties, which enable them to exhibit wide range of pharmacological activities ranging from anti-fungal, anti-neoplastic, anti-helmintic, anti-microbial etc. Owing to their electron rich ring system, imidazole and piperazine based motifs have become an attractive target for design and development of novel chemical structures as new drugs. In the current study, we ...


Two-Way Regulation Of Mmpl3 Expression Identifies And Validates Inhibitors Of Mmpl3 Function In Mycobacterium Tuberculosis, Shipra Grover, Curtis A. Engelhart, Esther Perez-Herran, Wei Li, Katherine A. Abrahams, Kadamba Papavinasasundaram, James M. Bean, Christopher M. Sassetti, Alfonso Mendoza-Losana, Gurdyal S. Besra, Mary Jackson, Dirk Schnappinger Jan 2021

Two-Way Regulation Of Mmpl3 Expression Identifies And Validates Inhibitors Of Mmpl3 Function In Mycobacterium Tuberculosis, Shipra Grover, Curtis A. Engelhart, Esther Perez-Herran, Wei Li, Katherine A. Abrahams, Kadamba Papavinasasundaram, James M. Bean, Christopher M. Sassetti, Alfonso Mendoza-Losana, Gurdyal S. Besra, Mary Jackson, Dirk Schnappinger

Open Access Publications by UMMS Authors

MmpL3, an essential mycolate transporter in the inner membrane of Mycobacterium tuberculosis (Mtb), has been identified as a target of multiple, chemically diverse antitubercular drugs. However, several of these molecules seem to have secondary targets and inhibit bacterial growth by more than one mechanism. Here, we describe a cell-based assay that utilizes two-way regulation of MmpL3 expression to readily identify MmpL3-specific inhibitors. We successfully used this assay to identify a novel guanidine-based MmpL3 inhibitor from a library of 220 compounds that inhibit growth of Mtb by largely unknown mechanisms. We furthermore identified inhibitors of cytochrome bc1-aa3 oxidase as one class ...


Using Nmr Spectroscopy And Computational Chemistry To Confirm The Structure Of Novel Antibiotic Nocamycin O, Stephanie Lewis Jan 2021

Using Nmr Spectroscopy And Computational Chemistry To Confirm The Structure Of Novel Antibiotic Nocamycin O, Stephanie Lewis

CMC Senior Theses

In recent years, many medically promising antibiotics have been discovered in nature, especially in insect-microbe symbioses. One of the better-studied examples of this kind of defensive relationship is that of fungus-growing ants and the antibiotic-producing Actinobacteria. These bacteria produce several defensive chemicals with myriad uses, including one antibiotic that inhibits the growth of several bacterial strains, including other Actinobacteria. This antibiotic (known as nocamycin O) is a promising candidate for medicinal use due to its similarities to bacterial RNA polymerase inhibitors tirandamycin and streptolydigin, which inhibit several human pathogens. The determination of the structure of nocamycin O will be an ...


Synthesis Of Dual Small Molecule Hybrids To Probe The Synergy Between Dna Repair Enzymes And Ido1, Nathaniel George Jan 2021

Synthesis Of Dual Small Molecule Hybrids To Probe The Synergy Between Dna Repair Enzymes And Ido1, Nathaniel George

Theses and Dissertations--Chemistry

Indoleamine 2 3-dioxygenase (IDO) has recently been highlighted as a promising target for small molecule based immunotherapy. IDO is often coopted by various cancer cells to promote an immune-suppressive environment around tumors. DNA damage repair (DDR) enzymes have recently been targeted for inhibition to promote genetic instability and bolster immune recognition. DDR enzymes such as PARP and POLγ are common inhibition targets due to their direct effects on cellular function. In the process of designing conjugate inhibitors of IDO and DDR enzymes, novel synthetic methodology was developed for the mild deprotection of N-Tert-butyloxycarbonyl (N-BOC) group from various amines. Conjugate ...


Docosanoic Acid Conjugation To Sirna Enables Functional And Safe Delivery To Skeletal And Cardiac Muscles, Annabelle Biscans, Jillian Caiazzi, Nicholas Mchugh, Vignesh Hariharan, Manish Muhuri, Anastasia Khvorova Dec 2020

Docosanoic Acid Conjugation To Sirna Enables Functional And Safe Delivery To Skeletal And Cardiac Muscles, Annabelle Biscans, Jillian Caiazzi, Nicholas Mchugh, Vignesh Hariharan, Manish Muhuri, Anastasia Khvorova

Open Access Publications by UMMS Authors

Oligonucleotide therapeutics hold promise for the treatment of muscle- and heart-related diseases. However, oligonucleotide delivery across the continuous endothelium of muscle tissue is challenging. Here, we demonstrate that docosanoic acid (DCA) conjugation of small interfering RNAs (siRNAs) enables efficient (~5% of injected dose), sustainable ( > 1 month), and non-toxic (no cytokine induction at 100 mg/kg) gene silencing in both skeletal and cardiac muscles after systemic injection. When designed to target myostatin (muscle growth regulation gene), siRNAs induced ~55% silencing in various muscle tissues and 80% silencing in heart, translating into a ~50% increase in muscle volume within 1 week. Our ...


Peptidylarginine Deiminase Inhibition Prevents Diabetes Development In Nod Mice, Fernanda M. C. Sodré, Samal Bissenova, Ylke Bruggeman, Ronak Tilvawala, Dana P. Cook, Claire Berthault, Santanu Mondal, Aïsha Callebaut, Sylvaine You, Raphael Scharfmann, Roberto Mallone, Paul R. Thompson, Chantal Mathieu, Mijke Buitinga, Lut Overbergh Nov 2020

Peptidylarginine Deiminase Inhibition Prevents Diabetes Development In Nod Mice, Fernanda M. C. Sodré, Samal Bissenova, Ylke Bruggeman, Ronak Tilvawala, Dana P. Cook, Claire Berthault, Santanu Mondal, Aïsha Callebaut, Sylvaine You, Raphael Scharfmann, Roberto Mallone, Paul R. Thompson, Chantal Mathieu, Mijke Buitinga, Lut Overbergh

Thompson Lab Publications

Protein citrullination plays a role in several autoimmune diseases. Its involvement in murine and human type 1 diabetes has recently been recognized through the discovery of antibodies and T-cell reactivity against citrullinated peptides. In the current study, we demonstrate that systemic inhibition of peptidylarginine deiminases (PADs), the enzymes mediating citrullination, through BB-Cl-amidine treatment, prevents diabetes development in NOD mice. This prevention was associated with reduced levels of citrullination in the pancreas, decreased circulating autoantibody titers against citrullinated GRP78 and reduced spontaneous NETosis of bone marrow-derived neutrophils. Moreover, BB-Cl-amidine treatment induced a shift from Th1 to Th2 cytokines in the serum ...


Coevolution, Dynamics And Allostery Conspire In Shaping Cooperative Binding And Signal Transmission Of The Sars-Cov-2 Spike Protein With Human Angiotensin-Converting Enzyme 2, Gennady M. Verkhivker Nov 2020

Coevolution, Dynamics And Allostery Conspire In Shaping Cooperative Binding And Signal Transmission Of The Sars-Cov-2 Spike Protein With Human Angiotensin-Converting Enzyme 2, Gennady M. Verkhivker

Mathematics, Physics, and Computer Science Faculty Articles and Research

Binding to the host receptor is a critical initial step for the coronavirus SARS-CoV-2 spike protein to enter into target cells and trigger virus transmission. A detailed dynamic and energetic view of the binding mechanisms underlying virus entry is not fully understood and the consensus around the molecular origins behind binding preferences of SARS-CoV-2 for binding with the angiotensin-converting enzyme 2 (ACE2) host receptor is yet to be established. In this work, we performed a comprehensive computational investigation in which sequence analysis and modeling of coevolutionary networks are combined with atomistic molecular simulations and comparative binding free energy analysis of ...


Synthesis, In Vitro, And In Vivo Evaluation Of Novel N-Phenylindazolyl Diarylureas As Potential Anti-Cancer Agents., Lucas N Solano, Grady L Nelson, Conor T Ronayne, Shirisha Jonnalagadda, Sravan K Jonnalagadda, Kaija Kottke, Robert Chitren, Joseph L Johnson, Manoj K Pandey, Subash C. Jonnalagadda, Venkatram R Mereddy Oct 2020

Synthesis, In Vitro, And In Vivo Evaluation Of Novel N-Phenylindazolyl Diarylureas As Potential Anti-Cancer Agents., Lucas N Solano, Grady L Nelson, Conor T Ronayne, Shirisha Jonnalagadda, Sravan K Jonnalagadda, Kaija Kottke, Robert Chitren, Joseph L Johnson, Manoj K Pandey, Subash C. Jonnalagadda, Venkatram R Mereddy

Faculty Scholarship for the College of Science & Mathematics

Novel N-phenylindazole based diarylureas have been designed, synthesized and evaluated as potential anticancer agents. In vitro cell viability studies of these derivatives illustrate good potency with IC50 values in the range of 0.4–50 μM in several cancer cell lines including murine metastatic breast cancer 4T1, murine glioblastoma GL261, human triple negative breast cancer MDA-MB-231, human pancreatic cancer MIAPaCa-2, and human colorectal cancer cell line WiDr. The ester group in the lead compound 8i was modified to incorporate amino-amides to increase solubility and stability while retaining biological activity. Further in vitro studies reveal that lead candidates inhibit tube length ...


Weak Binding To The A2re Rna Rigidifies Hnrnpa2 Rrms And Reduces Liquid–Liquid Phase Separation And Aggregation, Veronica H. Ryan, Scott Watters, Joshua Amaya, Balabhadra Khatiwada, Vincenzo Venditti, Mandar T. Naik, Nicolas L. Fawzi Sep 2020

Weak Binding To The A2re Rna Rigidifies Hnrnpa2 Rrms And Reduces Liquid–Liquid Phase Separation And Aggregation, Veronica H. Ryan, Scott Watters, Joshua Amaya, Balabhadra Khatiwada, Vincenzo Venditti, Mandar T. Naik, Nicolas L. Fawzi

Chemistry Publications

hnRNPA2 is a major component of mRNA transport granules in oligodendrocytes and neurons. However, the structural details of how hnRNPA2 binds the A2 recognition element (A2RE) and if this sequence stimulates granule formation by enhancing phase separation of hnRNPA2 has not yet been studied. Using solution NMR and biophysical studies, we find that each of the two individual RRMs retain the domain structure observed in complex with RNA but are not rigidly confined (i.e. they move independently) in solution in the absence of RNA. hnRNPA2 RRMs bind the minimal rA2RE11 weakly but at least, and most likely, two hnRNPA2 ...


Isolation, Structure Elucidation, And Synthesis Of Natural Products From Marine Cyanobacteria, Keren Solomon Aug 2020

Isolation, Structure Elucidation, And Synthesis Of Natural Products From Marine Cyanobacteria, Keren Solomon

Electronic Theses and Dissertations

This thesis describes the isolation, structure elucidation, and synthesis of natural products from marine cyanobacteria. A crude extract from a cyanobacterium collected in Curacao showed selective affinity for the dopamine D5 receptor in a screen against a panel of CNS receptors. Due to the high similarity of the D5 and D1 receptor, to date there are no known ligands that differentiate them. Attempts to purify the compound responsible for this affinity led to the isolation of the known compound caylobolide A. A second extract from a cyanobacterium collected in Panama underwent bioassay-guided fractionation and yielded the novel ...


Separation And Identification Of Permethylated Glycan Isomers By Reversed Phase Nanolc-Nsi-Msn [Preprint], Simone Kurz, M. Osman Sheikh, Shan Lu, Lance Wells, Michael Tiemeyer Aug 2020

Separation And Identification Of Permethylated Glycan Isomers By Reversed Phase Nanolc-Nsi-Msn [Preprint], Simone Kurz, M. Osman Sheikh, Shan Lu, Lance Wells, Michael Tiemeyer

University of Massachusetts Medical School Faculty Publications

High performance liquid chromatography has been employed for decades to enhance detection sensitivity and quantification of complex analytes within biological mixtures. Among these analytes, glycans released from glycoproteins and glycolipids have been characterized as underivatized or fluorescently tagged derivatives by HPLC coupled to various detection methods. These approaches have proven extremely useful for profiling the structural diversity of glycoprotein and glycolipid glycosylation but require the availability of glycan standards and secondary orthogonal degradation strategies to validate structural assignments. A robust method for HPLC separation of glycans as their permethylated derivatives, coupled with in-line MSn fragmentation to assign structural features independent ...


Visualization Without Vision – How Blind And Visually Impaired Students And Researchers Engage With Molecular Structures, Croix J. Laconsay, Henry B. Wedler, Dean J. Tantillo Jul 2020

Visualization Without Vision – How Blind And Visually Impaired Students And Researchers Engage With Molecular Structures, Croix J. Laconsay, Henry B. Wedler, Dean J. Tantillo

Journal of Science Education for Students with Disabilities

This article examines the tools and techniques currently available that enable blind and visually impaired (BVI) individuals to visualize three-dimensional objects used in learning chemistry concepts. How BVI individuals engage with and visualize molecular structure is discussed and recent tactile (or haptic) and auditory methods for visualization of various chemistry concepts are summarized. Remaining challenges for chemistry education researchers are described with the aim of highlighting the potential value of educational research in further enabling BVI students to pursue careers in science, technology, engineering, and mathematics (STEM) fields.


Chemical Manipulation Of Macrophages: Nanomaterial And Molecular Approaches, Joseph Hardie Jul 2020

Chemical Manipulation Of Macrophages: Nanomaterial And Molecular Approaches, Joseph Hardie

Doctoral Dissertations

Macrophages, phagocytic cells of the innate immune system, are the body’s first line of defense against pathogens and are responsible for tissue maintenance. Macrophages are capable of sensing and internalizing external stimuli, and in response change their morphology and phenotype accordingly. Because macrophages are integral to immune function and tissue maintenance, dysregulation of macrophage behavior is associated with a range of diseases including infections, cancer, autoimmune disorders, atherosclerosis, and more. Because of the implications of macrophage failure, there is interest in creating new materials to manipulate macrophage behavior for a therapeutic effect. In this thesis, I describe the application ...


Synthesis Of The Natural Alkaloids Angustureine, Cuspareine, Galipeine, Galipinine Using Α-Aminocycloalkyl Copper Reagents, Zane Bertoli May 2020

Synthesis Of The Natural Alkaloids Angustureine, Cuspareine, Galipeine, Galipinine Using Α-Aminocycloalkyl Copper Reagents, Zane Bertoli

Master of Science in Chemical Sciences Theses

Tetrahydroquinolines (THQs) are a group of N-heterocyclic molecules derived from natural sources. They show a wide range of interesting biological activity and have been the basis for a variety of different medications including antibacterial and antiparasitic drugs. The Hancock alkaloids, Galipinine, Galipeine, Cuspareine and Angustureine, are natural 1,2,3,4- tetrahydroquinoline compounds that are found in the South American Angostura tree. Extracts containing these alkaloids have been used to treat fever, dysentery and other ailments. Interestingly, These compounds have shows in vitro antimalarial activity. However, it does not appear in the literature that they have been evaluated for their ...


Synthesis And Evaluation Of Novel Biologically Active Compounds, Madhurima Das May 2020

Synthesis And Evaluation Of Novel Biologically Active Compounds, Madhurima Das

University of New Orleans Theses and Dissertations

SCP-1, a potent derivative of acetaminophen, exhibits significantly diminished hepatotoxicity and nephrotoxicity relative to acetaminophen and nitrate ester derivatives of acetaminophen. It was therefore of interest to explore the development of nitric oxide donor analogs of SCP-1 to identify compounds that could have enhanced analgesic and/or antipyretic activity while taking advantage of the very low liver and kidney toxicity inherent to SCP-1. In this project, a series of nitrate ester analogues of the SCP-1 were prepared as potential nitric oxide donors. The synthesis of SCP analogs was achieved by triflic acid catalyzed O-acylation of SCP-1 with chloroalkanoyl chlorides followed ...


Flavonoid And Cannabidiol Neural Glyoxalase Pathway Enhancement Against Aging And Alzheimer’S Disease, Joel R. Frandsen May 2020

Flavonoid And Cannabidiol Neural Glyoxalase Pathway Enhancement Against Aging And Alzheimer’S Disease, Joel R. Frandsen

Theses & Dissertations

Alzheimer’s Disease is a neurodegenerative condition featuring neural cell death and a decline in cognitive capacity caused by elevated inflammation and production of reactive oxygen species. The glyoxalase pathway is an endogenous antioxidant system that neutralizes reactive methylglyoxal through sequential reactions. Dysfunction of the glyoxalase pathway contributes to oxidative stress and the accumulation of inflammatory metabolic byproducts. Plant-produced compounds with antioxidant activity can enhance endogenous antioxidant pathways and protect cells from elevated ROS production. We hypothesize that flavonoids and limited Cannabis Sativa-produced cannabidiol can enhance glyoxalase pathway function through regulation of antioxidant and pro-apoptotic signaling pathways to prevent ...


Silver-Catalyzed Synthesis Of Disubstituted Fluorinated Isoxazoles, Micah Stewart May 2020

Silver-Catalyzed Synthesis Of Disubstituted Fluorinated Isoxazoles, Micah Stewart

Honors Theses

The presence of fluorine can provide organic compounds with useful biological properties, such as increased metabolic stability and drug uptake. Because of these advantages, fluorinated compounds make up about 30% of the drug industry. However, fluorination of complex molecules is difficult due to fluorine’s high electronegativity.

Fluorinated isoxazoles are of particular interest in the pharmaceutical industry. Isoxazoles are five-membered heterocycles with oxygen and nitrogen in the 1, 2 positions that are able to engage in interactions unavailable to other ring structures, conferring advantageous biological properties upon compounds containing them. However, there are limited synthetic routes for fluorinated isoxazoles, and ...


Isolation, Identification, And Investigation Of A Novel Bioactive Furanocoumarin From Leaves Of Amyris Elemifera, Amy K. Bracken May 2020

Isolation, Identification, And Investigation Of A Novel Bioactive Furanocoumarin From Leaves Of Amyris Elemifera, Amy K. Bracken

Honors Theses

Plants produce biologically active compounds that humans have utilized for many agricultural applications. Amyris elemifera was investigated due to the known bioactivity of its family, Rutaceae, and its use in medicines in tribes of the Bahamas. Biotage® and TLC guided fractionation of the EtOAc, hexane, and MeOH extracts of the leaves of Amyris elemifera yielded bioactive compounds. Most significantly, a novel furanocoumarin, 8-(3-methylbut-2-enyloxy)-marmesin acetate (1), and its analog 8-(3-methylbut-2-enyloxy)-marmesin (2), were isolated. The structures were identified via NMR and X-ray crystallography techniques; the X-ray crystal structure for 1 was reported for the first time, and the ...