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Effect Of Peptide Hydrolysates From Riceberry On Reducing Endoplasmic Reticulum Stress In Cells, Theeranuch Jaroenchuensiri

Chulalongkorn University Theses and Dissertations (Chula ETD)

Oxidative stress, resulting from an imbalance between reactive oxygen species (ROS) and antioxidants, contributes to diseases and induces endoplasmic reticulum (ER) stress. Antioxidants can mitigate ER stress. We investigated synthetic peptides from riceberry rice hydrolysates against ER stress. Ten peptides were evaluated for toxicity and antioxidant activity in SH-SY5Y and L929 cell lines. Peptides ID 3 to ID 5 ,and ID 10 showed significant antioxidant activity protecting cells from oxidative stress induced by IAA and H2O2. These peptides alleviated ER stress induced by TM, as observed through fluorescence microscopy analysis using ConA dye. Peptides ID 3 to 5 reduced ConA …

Analysis Of Sex-Specific Prostanoid Production Using A Mouse Model Of Selective Cyclooxygenase-2 Inhibition, Rita K. Upmacis, Wendy L. Becker, Donna M. Rattendi, Raven S. Bell, Kelsey D. Jordan, Shayan Saniei, Elena Mejia

Faculty Papers and Publications

Background: Prostanoids are a family of lipid mediators formed from arachidonic acid by cyclooxygenase enzymes and serve as biomarkers of vascular function. Prostanoid production may be different in males and females indicating that different therapeutic approaches may be required during disease.

Objecti ves: We examined sex-dependent differences in COX-related metabolites in genetically modified mice that produce a cyclooxygenase- 2 (COX2) enzyme containing a tyrosine 385 to phenylalanine (Y385F) mutation. This mutation renders the COX2 enzyme unable to form a key intermediate radical required for complete arachidonic acid metabolism and provides a model of selective COX2 inhibition.

Design and …

Poly(Β-Gal-Thr): A New Scalable Synthetic Mucin, Manuel A. Lema

Dissertations and Theses

A method for the preparation of glycosylated polypeptides via the nucleophilic ring-opening polymerization of a glycosylated N-carboxyanhydride (NCA) monomer is reported. The synthesis of 2,3,4,6-tetraacetyl-β-galactose-threonine N-carboxyanhydride (β-AcO-Gal-Thr-NCA) monomer in 5 steps with an 8 % overall yield is described, and the single-crystal X-ray structure is provided. The effect of a series of Ni⁰-based organometallic initiators, nucleophilic amine initiators, co-catalysts, and solvents on the polymerization were explored. The kinetics of the three most promising conditions were studied in greater detail. The conditions that provided the highest yield, low polydispersity (Ð), and …

Copper(Ii) And Silver(I)‑1,10‑Phenanthroline‑5,6‑Dione Complexes Interact With Double‑Stranded Dna: Further Evidence Of Their Apparent Multi‑Modal Activity Towards Pseudomonas Aeruginosa, Anna Clara Milesi Galdino, Lívia Viganor, Matheus Mendonça Pereira, Michael Devereux, Malachy Mccann, Marta Helena Branquinha, Zara Molphy, Sinéad O'Carroll, Conor Bain, Georgia Menounou, Andrew Kellett, André Luis Souza Dos Santos

Articles

Tackling microbial resistance requires continuous efforts for the development of new molecules with novel mechanisms of action and potent antimicrobial activity. Our group has previously identified metal-based compounds, [Ag(1,10-phenanthroline-5,6-dione)2]ClO4 (Ag-phendione) and [Cu(1,10-phenanthroline-5,6-dione)3](ClO4)2.4H2O (Cu-phendione), with efficient antimicrobial action against multidrug-resistant species. Herein, we investigated the ability of Ag-phendione and Cu-phendione to bind with double-stranded DNA using a combination of in silico and in vitro approaches. Molecular docking revealed that both phendione derivatives can interact with the DNA by hydrogen bonding, hydrophobic and electrostatic interactions. Cu-phendione exhibited the highest binding affinity to either major (− 7.9 kcal/mol) or minor (− 7.2 kcal/mol) …

Advancing Competency In Managing Risk And Knowledge: Steps Toward Operationalisation Of The Risk-Knowledge Infinity Cycle (Rki Cycle) - Part 1: Improving Effectiveness Of Risk-Based Decision Making (Rbdm), Martin Lipa, Paige Kane, Anne Greene

Articles

To date, literature on the Risk-Knowledge Infinity Cycle (RKI Cycle) has mainly been theoretical. This paper series intent is to focus on the operationalisation of the RKI Cycle by describing a series of steps – the “How to” – for RKI Cycle deployment, to help move the RKI Cycle from theory to practice. The first paper in this series focuses on how the RKI Cycle can support effective Risk-Based Decision Making (RBDM).

Oxidative Damage To Brain Cells Underlies: (I) Resistance To Radiation And Increased Tumor Cell Growth In Glioblastoma; (Ii) Apoe Allele Status And Pentose Phosphate Pathway Proteins In Alzheimer Disease Mouse Models, Nicole Rummel

Theses and Dissertations--Chemistry

Oxidative phosphorylation occurs within the inner mitochondrial membrane producing ATP for the cell’s energy needs. The Electron Transport Chain carries out the transfer of electrons from electron carriers through a series of proteins to form a proton gradient across the inner mitochondrial membrane. This gradient acts as the energy source needed to put a phosphate onto ADP and form ATP. With the large amounts of free electrons and oxygen within the mitochondria, an inevitable by-product of free radicals in the form of superoxide are produced. Superoxide (O^-̇₂) is a reactive radical that can react further to …

Synthesis Of 6,6- And 7,7-Difluoro-1-Acetamidopyrrolizidines And Their Oxidation Catalyzed By The Nonheme Fe Oxygenase Lolo, Nabin Panth

Theses and Dissertations--Chemistry

One of the remarkable steps in loline alkaloid biosynthesis is the installation of an ether bridge between two unactivated C atoms in 1-exo-acetamidopyrrolizidine (AcAP). LolO, a 2-oxoglutarate-dependent nonheme Fe oxygenase, catalyzes both the hydroxylation of AcAP and the resulting alcohol's cycloetherification to give N-acetylnornoline (NANL). The mechanism of hydroxylation is well understood, but the mechanism of the oxacyclization is not. I synthesized difluorinated analogs of AcAP in an attempt to further understand the mechanism of the unusual cycloetherification step.

I prepared 6,6-F₂-AcAP in eight steps from N,O-protected 4-oxoproline. The key step was a Dieckmann …

Mass Spectrometric Analysis Of Lignin Model Compounds: Fundamental Investigations Of Ionization And Supramolecular Interactions For Lignocellulosic Biomass Applications, Kimberly Dean

Theses and Dissertations--Chemistry

Lignocellulosic biomass is pivotal for the development of renewable energy sources and materials essential to mitigate the exploitation of fossil fuels causing climate change and environmental pollution issues. The conversion of biomass into fuel requires the hydrolysis of cellulose and a biproduct of this process is the isolation of millions of tons of lignin as biorefinery waste. Lignin is a complex high molecular weight polymer whose structure remains undefined and critically limits potential industrial applications of lignocellulosic biomass. The advancement of analytical methods for structural elucidation of lignin and its ensemble of phenolic compounds is therefore essential to advance this …

The Role Of Charge On Dna Packaging And Integrity Within Reconstituted Peptide-Dna Assemblies, Ehigbai Oikeh

Theses and Dissertations--Chemistry

In nature, DNA exists primarily in a highly compacted form. The compaction of DNA in vivo is mediated by cationic proteins; histone in somatic nuclei and arginine-rich peptides called protamines in sperm chromatin. The packaging in the sperm nucleus is significantly higher than somatic nuclei resulting in a final volume roughly 1/20^th that of a somatic nucleus. This tight packaging results in a near crystalline packaging of the DNA helices. While the dense packaging of DNA in sperm nuclei is considered essential for both efficient genetic delivery as well as DNA protection against damage by mutagens and oxidative species, …

Development Of Fluorescence Based Approaches To Understand Astrocyte Biology In The Context Of Nicotine And Nicotinic Receptor Activity, Surya P. Aryal

Theses and Dissertations--Chemistry

Smoking and tobacco use (STU) is a major global health problem and worldwide more than six million people die due to tobacco related diseases each year. Although majority of smokers try to quit smoking several times in their life, traditional therapeutic approaches, which focus only on neuronal cells, have a very low success rate. Understanding the effect of nicotine on glial cells, synaptic communication and blood vasculature in the brain can provide further insights on the neurobiology of substance abuse and can potentially help to design better therapeutic approaches. Glial cells are non-excitable cells in the brain which do not …

Application Of Mass Spectrometry For Characterization Of Plant-Based Phenolics And Alkaloids, Masoumeh Dorrani

Theses and Dissertations--Chemistry

Plant-derived compounds have the potential to produce value-added compounds with a variety of applications. For example, the lignin part of the lignocellulosic biomass, produced in large quantities as waste from the paper and pulp industries, is a rich source of phenolics with potential applications in the renewable energy sector, pharmaceutical, and chemical industries. On the other hand, plant alkaloids are the primary source for developing plant-derived therapeutics. Unfortunately, the recalcitrant nature of plant cell walls, low extraction yields of small secondary metabolites, and the lack of effective analytical methods for a rapid and accurate identification of plant-based compounds and plant’s …

Nanomaterial Synthesis And Real Time Investigation Of Thermal Effects On Nanomaterial And Nano-Interfaces For Real World Applications, Rose H. Pham

Theses and Dissertations--Chemistry

As interest in nanomaterials and nanotechnology continues to grow, so does the need for more efficient and economical synthesis methods to keep up with the demand. The applications for nanomaterials are seemingly endless as they have functions in energy, biomedical, environmental, and many more. Working to develop different morphologies and sizes of nanomaterials will further help expand its utility. With the use of advanced characterization techniques such as in situ transmission electron microscopy (TEM), real time studies on the effects of external forces on nanomaterials are possible under controlled environments. This will give insight on how nanomaterials will perform in …

Development Of Ph-Sensitive And Amine-Reactive Lifters For The Detection Of Latent Fingermarks, Andrei Gregory Mlakar

Graduate Research Theses & Dissertations

Latent fingermarks are among the most common forms of physical evidence left at crime scenes. Being composed largely of eccrine and sebaceous secretions, they are typically invisible unless they are treated with, e.g., powders or cyanoacrylate fumes. Drawbacks to these and other commonly used methods, however, may include limited substrate compatibility, safety hazards, inability to detect older marks, and the need for expensive instrumentation and expert practitioners. Fingermarks on curved, reflective, patterned, or luminescent substrates are particularly challenging to image with most common techniques. After treatment, fingermarks on such difficult substrates may be transferred to, or “lifted” by, flexible adhesives, …

A Study Of Π – Π Stacking Interactions In Rhenium Carbonyl Complexes Based On Backbone Functionalized Bis(Pyrazolyl)Methane Ligands, Balamani Guduru

Masters Theses

π – π Stacking interactions are one of the most important non-covalent inter-molecular forces, which play an important role in the architecture of 1D and 2D networks of supramolecular chemistry. This associative contact involves the attractive interactions of aromatic molecules with each other. To describe and study the strength of the π – π stacking interactions, four new bis(pyrazolyl)ethanamine ligands having different aromatic groups (1-pyrenyl, 1-naphthyl, 2-naphthyl, and 9-anthracenyl) known for their propensity to be involved in π – π stacking interactions were prepared by the reaction of one equivalent of bis(pyrazolyl)ethanamine with one equivalent of the corresponding aromatic aldehyde. …

The Design And Synthesis Of New Organic Dithiols For Environmental Applications, Shashika Nadishani Bandara

Theses and Dissertations--Chemistry

A thiol molecule, 2,6-pyridinediamidoethanethiol (PB9), was synthesized based on the pyridine-2,6-dicarboxamide scaffold with appended cysteamine groups. PB9 acts as an effective chelator for Pb(II) due to multiple binding sites (N₃S₂) through irreversible binding precipitating Pb(II). Removal of aqueous Pb(II) from solution was demonstrated by exploring the effects of time, initial PB9:Pb(II) ratios, pH, exposure time, and solution temperature. After 15 min the Pb(II) concentrations were reduced from 50.00 ppm to 0.30 ppm (99.4%) and 0.25 ppm (99.5%) for PB9:Pb ratios of 1:1 and 2:1, respectively. Removal of > 93% Pb(II) was observed over multiple pH values with …

1,2-Diamination Of Alkenes Via Reduction Of 1,2,3-Triazolinium Ions, Setareh Saryazdi

Theses and Dissertations--Chemistry

1,2-Diamine substructures are prevalent functional motifs in natural products, pharmaceutical compounds, and ligands. The interesting functionalities of 1,2-diamines have inspired many synthetic chemists to design various methodologies for preparing these structures from simple precursors such as alkenes. In this work, we described two different but related methods using simple and easily accessible reagents for 1,2-diamination of alkenes. In the first method, an alkene undergoes 1,3-dipolar cycloaddition with an organic azide to form a 1,2,3-triazoline. Subsequent N-alkylation of the generated 1,2,3-triazoline gives the 1,2,3-triazolinium ion, which is then hydrogenated over Raney Ni with a balloon of H₂ to produce …

Genomic Analysis Of Pollen Grains For Forensic Applications, Luz Kelley

Electronic Theses and Dissertations, 2020-2023

With over 300,000 plant species on the planet and more than 90% of them relying on pollen for reproduction, palynology, the study of pollen grains plays a vital role in many research fields. One of them is forensic palynology, which uses pollen as a proxy to link individuals or objects to a location or instance. It relies on the fact that (1) pollen is an ever-present feature of the environment; (2) different locations have different pollen signatures, allowing for inference related to spatial tracking; (3) plants bloom at different times, allowing for temporal inference; and (4) pollen is exceptionally durable …

Density Functional Theory Of Samarium(Ii) Reactivity In Thf And Water, Parisa Fasihianifard

Dissertations and Theses

Sm(II) diiodide is widely used in organic synthesis for the reduction of functional groups such as esters, anhydrides, amides, carbonyls, and arenes. Moreover, in aqueous systems and in mixtures of water and THF, the addition of Sm(II) diiodide can reduce water directly resulting in the formation of hydrogen gas. However, the mechanism of these reactions is not completely understood, making it difficult to improve experimental design. The reaction can proceed either through subsequent electron-transfer proton-transfer (ET-PT), subsequent proton transfer electron-transfer (PT-ET), or via proton coupled electron transfer (PCET). Density functional theory (DFT) calculations were performed to understand the speciation of …

Semiconducting Polymer Dots-Based Ratiometric Fluorescent Probes For Detection Of Biomarkers, Shuyi He

Dissertations and Theses

Biomarkers serve a key role in illness diagnosis and treatment. Importantly, early detection can boost the therapy success rate greatly. However, traditional approaches to detect biomarkers based on fluorescence intensity changes of individual fluorophores did not completely realize the potential due to several technical problems such as low sensitivity. Ratiometric fluorescent methods use changes in the intensity of two or more emission bands (caused by the analyte) to create an internal reference that improves detection sensitivity. Due to their unique photophysical properties, such as high fluorescence intensity, high quantum yield, and low toxicity, semiconductor quantum dots (Pdots) are an ideal …

Gas-Phase Acid-Base Properties And Conformations Of Oligopeptides Through Mass Spectrometry And Computational Studies, Yuntao Zhang

University of the Pacific Theses and Dissertations

This dissertation presents a comprehensive study of the peptides of interest to deeper understand the gas-phase acid-base properties in relation to their conformations and chirality. In the first part of the study, two pairs of alanine (A)-based isomeric peptides consisting of a basic probe, lysine (Lys) or 2,3-diaminopropionic acid (Dap), were investigated to understand the nature of the enhanced basicity when the basic probe was moved from the N-terminus to the C-terminus. In the second part of the study, alanine-based peptides containing a cysteine (C) as the acidic probe were investigated to understand the chirality effects on the gas-phase acidity …

Investigation Of Intramolecular And Intermolecular Aza-Michael Reactions, Nadia Z. Singleton

College of Graduate Studies: Theses & Dissertations

The hydroamination of dimaleimides with diamines has been accomplished to access novel polymers. Various dimaleamides and dimaleimides were synthesized from commercially available diamines and maleic anhydride. The resulting dimaleamides were then ring-closed to their respective dimaleimides either directly in the presence of acid or via the synthesis of mixed amide-esters which then ring close in the presence of acid under heat. Hydroamination of the dimaleimides with piperazine was accomplished in bulk at room temperature. The reaction is spontaneous thus leading to the formation of polyimides with high functional group conversion within minutes. The kinetics of the maleamides and maleimides was …

Stratospheric Aerosol Composition Observed By The Atmospheric Chemistry Experiment Following The 2019 Raikoke Eruption, Chris D. Boone, Peter F. Bernath, Keith Labelle, Jeff Crouse

Chemistry & Biochemistry Faculty Publications

Infrared aerosol spectra derived from Atmospheric Chemistry Experiment measurements following the June 2019 Raikoke volcanic eruption are used to evaluate the composition of stratospheric aerosols in the Arctic. A blanket of aerosols, spanning an altitude range from the tropopause (8–11 km) to 20 km, persisted in the stratosphere over northern latitudes for many months. The aerosols within this blanket were almost exclusively sulfates. The percentage of sulfuric acid in the aerosols decreased over time, dropping below 50% H₂SO₄ concentration at some altitudes by March 2020. Contrary to previous reports, the aerosol blanket was not comprised of smoke …

Design And Synthesis Of Purine Based Neuroprotectors And Novel Synthetic Methods For The Trifluoromethylation Of Aldehyde Hydrazones, Puspa Aryal

Doctoral Dissertations

"Purine-derived compounds are widely investigated as cyclin-dependent kinase inhibitors that have broad applications in the design of pharmaceuticals for treating diseases, such as diabetes, atherosclerosis, and cancers. Towards the goal of effective AGE-inhibitors, and neuroprotector compounds we have synthesized a series of novel purine-based triazoles and investigated their neuroprotective effects, using SHSY-3Y human neuroblastoma cell line. Through these studies, we have identified purine-based neuroprotector compounds that favorably modulate oxidative stress induced by the Fenton reaction-generated reactive oxygen species (ROS).

The C(sp²−H)-trifluoromethylation of hydrazones would give access to the αtrifluoromethylated hydrazones that can serve as intermediates in the synthesis …

Peripherally Restricted Opioid Conjugates And Its Use As Pharmacological Probes And Potential Therapeutics, Md Tariqul Haque Tuhin

University of the Pacific Theses and Dissertations

Opioid-induced constipation (OIC) is one of the major adverse effects of opioid analgesics used by millions of patients each year. While progress has been made, there remains a significant unmet medical need in the treatment of OIC. Major gaps remain in our understanding of the role of the gastrointestinal tract and central nervous system (CNS) in precipitating OIC. For the last four decades, numerous investigations to study the sites of action of opioid analgesics have utilized peripherally acting mu-opioid receptor antagonists (PAMORAs), which have been incorrectly believed to have limited penetration across the blood-brain barrier (BBB). Several preclinical and clinical …

Biocatalytic Intramolecular C−H Aminations Via Engineered Heme Proteins: Full Reaction Pathways And Axial Ligand Effects, Yang Wei, Melissa Conklin, Yong Zhang

Chemistry: Faculty Publications and Other Works

Engineered heme protein biocatalysts provide an efficient and sustainable approach to develop amine-containing compounds through C−H amination. A quantum chemical study to reveal the complete heme catalyzed intramolecular C−H amination pathway and protein axial ligand effect was reported, using reactions of an experimentally used arylsulfonylazide with hemes containing L=none, SH−, MeO−, and MeOH to simulate no axial ligand, negatively charged Cys and Ser ligands, and a neutral ligand for comparison. Nitrene formation was found as the overall rate-determining step (RDS) and the catalyst with Ser ligand has the best reactivity, consistent with experimental reports. Both RDS and non-RDS (nitrene transfer) …

Development Of Electrochemical Detection For Cortisol And Hepatitis C Virus Core Antigen, Pannaporn Pusomjit

Chulalongkorn University Theses and Dissertations (Chula ETD)

This dissertation focused on the development of electrochemical biosensors for the determination of essential biomarkers by using a label-free assay. This dissertation can be divided into two parts. In the first part, a non-invasive aptamer-based electrochemical biosensor using disposable screen-printed graphene electrodes (SPGEs) was developed for simple, rapid, and sensitive determination of cortisol. The specific recognition of the cortisol DNA aptamer (CApt) was modified with streptavidin magnetic beads (MBs) before simple immobilization onto the electrode surface using a neodymium magnet. The electrochemical behavior of the aptamer-based biosensor was assessed by using electrochemical impedance spectroscopy (EIS) and cyclic voltammetry (CV). Furthermore, …

Surface-Enhanced Raman Scattering Technique For Nanoplastics Detection, Boonphop Chaisrikhwun

Chulalongkorn University Theses and Dissertations (Chula ETD)

The size-dependent effect of nanoplastics (NPLs) restricts the quantification of NPLs by surface-enhanced Raman scattering (SERS) technique. In this study, we successfully established an innovative preparation method to eliminate this effect. This developed SERS method allowed us to quantify 100-, 300-, 600-, and 800-nm polystyrene nanospheres (PSNSs) in diverse aqueous conditions at a low concentration. The SERS substrate was easily fabricated and used as NPLs signal enhancement with sputtering gold particles onto a glass cover slide. By preconcentrating and dissolving PSNSs in toluene, SERS technique can be successfully quantify NPLs at extremely low concentrations with a limit of detection (LOD) …

Enzyme-Free Hydrogen Peroxide Sensor From Dual-Shaped Plasmonic Silver Nanoparticles, Charles Oliver Avenido

Chulalongkorn University Theses and Dissertations (Chula ETD)

A novel growth-based strategy for the determination of hydrogen peroxide has been developed using a mixture of silver nanospheres (AgNSs) and citrate-capped silver nanoprisms (AgNPrs). The unique ability of hydrogen peroxide to oxidize silver nanoparticles and reduce silver metal consequently was exploited to produce a highly sensitive and selective sensor (AgNSs/NPrs). Citrate-capping of the AgNPrs only allows the lateral growth that resulted in a red shift and intensity enhancement of the in-plane dipole plasmon resonance (IPDPR) band. Consequently, distinct hues from yellow, orange, red, purple to blue were produced from the diluted sensors. Ratiometric analysis was employed to quantify H2O2 …

Theoretical Study Of Lithium Absorption In Silicon Nanostructures For Application As Anodes In Lithium-Ion Batteries, Fadjar Mulya

Chulalongkorn University Theses and Dissertations (Chula ETD)

The absorption and adsorption of lithium in silicon nanostructures: silicon quantum dots (SiQDs), silicon nanowires (SiNWs) and silicon nanopores (SiNPs) were studied using density functional theory (DFT) with M06-2X hybrid functional and 6-31G+(d) basis set. The tetrahedral sites, both Tdinner and Tdsurface, are the most preferred sites for lithiation due to their favorable binding energy profiles. For single lithium absorption and adsorption, SiQDs exhibit a binding energy of 1 eV, SiNWs demonstrate a binding energy of 1.28 eV, and SiNPs display a binding energy of 0.73 eV. Similarly, multiple lithium adsorptions yield binding energies of 1.12 eV for SiQDs, 1.21 …

Dna-Templated Synthesis Of Cationic Styryl Dyes, Kriangsak Faikhruea

Chulalongkorn University Theses and Dissertations (Chula ETD)

Styryl dye is a class of pi-conjugated dye that shows several desirable optical properties, such as high photostability, solvatochromic characteristics, and high fluorescence quantum yields. Due to the responsiveness to the binding with the target biomolecules such as nucleic acids, some of these dyes have been widely employed for biomolecular detection and cellular imaging. These dyes are typically synthesized via an aldol-type reaction between a methyl heterocycle and an aromatic aldehyde in the presence of acid or base as a catalyst. However, the conventional method of synthesizing these dyes is inefficient, time-consuming, and involves the use of excessive chemicals, as …