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Articles 31 - 60 of 406
Full-Text Articles in Chemicals and Drugs
Morphological Test Of Areca Nut Fiber Ceramic Membrane Using Scanning Electron Microscopy Energy Dispersive X-Ray Mapping Spectroscopy, Amelia Marzain, Siti Umi Kalsum, Marhadi Marhadi, Ahmad Nabil Shahab
Morphological Test Of Areca Nut Fiber Ceramic Membrane Using Scanning Electron Microscopy Energy Dispersive X-Ray Mapping Spectroscopy, Amelia Marzain, Siti Umi Kalsum, Marhadi Marhadi, Ahmad Nabil Shahab
Journal of Materials Exploration and Findings
This study investigates the potential of ceramic membranes derived from areca nut fiber as a cost-effective and environmentally sustainable material for the removal of iron (Fe) and manganese (Mn) from groundwater. Two types of membranes were fabricated: one without activation and one chemically activated using 10% sodium hydroxide (NaOH). The morphological and elemental characteristics of both membranes were analyzed using Scanning Electron Microscopy (SEM) and Energy Dispersive X-ray (EDX) mapping. The concentrations of Fe and Mn before and after treatment were measured using Atomic Absorption Spectroscopy (AAS). The NaOH-activated membrane exhibited a more porous surface structure and higher oxygen content, …
Analysis Of Leakage In Nearshore Pipelines Using Fitness For Service Method To Ensure Mechanical Integrity Based On Api-579 Level 3, Elriandri Elriandri, Dedi Priadi
Analysis Of Leakage In Nearshore Pipelines Using Fitness For Service Method To Ensure Mechanical Integrity Based On Api-579 Level 3, Elriandri Elriandri, Dedi Priadi
Journal of Materials Exploration and Findings
The Fitness for Service (FFS) analysis is performed as a quantitative assessment to evaluate the integrity condition of a pipeline. Essentially, FFS assessment helps determine whether equipment components can operate safely despite existing deficiencies. This evaluation is carried out using the Finite Element Method (FEM). In the case of an underwater pipeline that experiences leak due to anchor pull at the flange connection, it undergoes plastic deformation and is lifted approximately 1 meter. As a mitigation step, inspection and repairs have been carried out by the company. Subsequently, modeling is performed to reconstruct the deformation process of the pipeline. Then, …
Allosteric Control Overcomes Steric Limitations For Neutralizing Antibodies Targeting Conserved Binding Epitopes Of The Sars-Cov-2 Spike Protein: Exploring The Intersection Of Binding, Allostery, And Immune Escape With A Multimodal Computational Approach, Mohammed Alshahrani, Vedant Parikh, Brandon Foley, Gennady M. Verkhivker
Allosteric Control Overcomes Steric Limitations For Neutralizing Antibodies Targeting Conserved Binding Epitopes Of The Sars-Cov-2 Spike Protein: Exploring The Intersection Of Binding, Allostery, And Immune Escape With A Multimodal Computational Approach, Mohammed Alshahrani, Vedant Parikh, Brandon Foley, Gennady M. Verkhivker
Mathematics, Physics, and Computer Science Faculty Articles and Research
Understanding the atomistic basis of multi-layer mechanisms employed by broadly reactive neutralizing antibodies of the SARS-CoV-2 spike protein without directly blocking receptor engagement remains an important challenge in coronavirus immunology. Class 4 antibodies represent an intriguing case: they target a deeply conserved, cryptic epitope on the receptor-binding domain yet exhibit variable neutralization potency across subgroups F1 (CR3022, EY6A, COVA1-16), F2 (DH1047), and F3 (S2X259). The molecular basis for this variability is not fully understood. Here, we employed a multi-modal computational approach integrating atomistic and coarse-grained molecular dynamics simulations, binding free energy calculations, mutational scanning, and dynamic network analysis to elucidate …
Techno-Enviro-Economic Approach For Electrification Of Rural And Shrimp Farming Regional Development Of An Isolated Island In Indonesia By Utilizing Hybrid Renewable Energy Systems, Fiqih Akbar Wijaya, Mohammad Akita Indianto
Techno-Enviro-Economic Approach For Electrification Of Rural And Shrimp Farming Regional Development Of An Isolated Island In Indonesia By Utilizing Hybrid Renewable Energy Systems, Fiqih Akbar Wijaya, Mohammad Akita Indianto
Journal of Materials Exploration and Findings
One of the challenges in developing and archipelagic countries such as Indonesia is maintaining energy demand in rural and isolated areas due to difficulties in electrical distribution. For instance, in areas like Bawean Island, no additional electricity capacity has been introduced in the past year, leading to an unmet potential customer demand. One of the possible options is by utilizing Hybrid Renewable Energy Systems (HRES) that are integrated with existing fossil fuel-based energy systems to support the growing energy demand in the remote island. A case study in Bawean Island is conducted with the projected energy demand covers the energy …
Remaining Life Assessment And Fitness For Service Evaluation Of Aging Chemical Reactors In Polyethylene Terephthalate Resin Industry, Aditya Pahlawan Munthe, Donanta Dhaneswara, Wahyuaji Narottama Putra, Gama Widyaputra
Remaining Life Assessment And Fitness For Service Evaluation Of Aging Chemical Reactors In Polyethylene Terephthalate Resin Industry, Aditya Pahlawan Munthe, Donanta Dhaneswara, Wahyuaji Narottama Putra, Gama Widyaputra
Journal of Materials Exploration and Findings
Aging chemical reactors in the polyethylene terephthalate (PET) resin industry require comprehensive evaluation to ensure safe continued operation. This study conducts a remaining life assessment (RLA) and fitness-for-service (FFS) evaluation on five 30-year-old reactors, based on API 510, API 579/ASME FFS-1, and ASME BPVC Section VIII Div. 1 standards. The analysis involves corrosion rate measurement, future corrosion allowance (FCA) projection, and minimum thickness verification. Among the reactors, R-120 was found to have the shortest remaining life less than 15 years. FFS assessments using three criteria Average Measured Thickness, MAWP from Point Thickness Readings, and Minimum Measured Thickness confirm that R-120 …
A Study Of Wear Measurement And Life Prediction Of Insert Chute Liner On Gold Ore Processing, Ferry Ardika Natanael, Nony Maulidya, Dedi Priadi
A Study Of Wear Measurement And Life Prediction Of Insert Chute Liner On Gold Ore Processing, Ferry Ardika Natanael, Nony Maulidya, Dedi Priadi
Journal of Materials Exploration and Findings
Chutes are critical materials handling assets to transport solid particles from one process step to another in mineral processing, coal mining and cement industries. The material transport, because of material characteristics, cause severe wear on internal lining of chutes or bins’ structure. The wear problem on internal lining of bins or chutes needs to be checked to keep production efficiency. Therefore, not checked wear rate causes liner replacement schedule becomes unpredictable. It leads to production loss and highly cost maintenance in industry. This study shows that condition-based maintenance through regular thickness measurement using Ultrasonic Transducer (UT) to predict life service …
Analysis Of Leak Testing Planning For Carbon Dioxide Piping Systems In The Development Of Carbon Capture, Utilization, And Storage Facilities In The Bintuni Basin, Devi Sentiani, Akhmad Herman Yuwono Professor
Analysis Of Leak Testing Planning For Carbon Dioxide Piping Systems In The Development Of Carbon Capture, Utilization, And Storage Facilities In The Bintuni Basin, Devi Sentiani, Akhmad Herman Yuwono Professor
Journal of Materials Exploration and Findings
Carbon Capture, Utilization, and Storage (CCUS) technologies have become a key strategic response to global efforts to reduce CO2 emissions. This study presents a leak testing strategy designed for a carbon dioxide (CO₂) piping system as part of a Carbon Capture, Utilization, and Storage (CCUS) project in the Bintuni Basin, West Papua, Indonesia. This study aims to ensure the system is properly prepared before commissioning by designing a leak test plan that is both practical and technical, based on ASME B31.3, ASME PCC-2, and API STD 520 Part 1. We conducted the process, which involves identifying the system boundaries, …
Dynamic Mutational Profiling Of Binding Interactions And Allosteric Networks In Conformational Ensembles Of The Sars-Cov-2 Spike Protein Complexes With Classes Of Antibodies Targeting Cryptic Binding Sites: Confluence Of Binding And Allostery Determines Molecular Mechanisms And Hotspots Of Immune Escape, Mohammed Alshahrani, Vedant Parikh, Brandon Foley, Gennady M. Verkhivker
Dynamic Mutational Profiling Of Binding Interactions And Allosteric Networks In Conformational Ensembles Of The Sars-Cov-2 Spike Protein Complexes With Classes Of Antibodies Targeting Cryptic Binding Sites: Confluence Of Binding And Allostery Determines Molecular Mechanisms And Hotspots Of Immune Escape, Mohammed Alshahrani, Vedant Parikh, Brandon Foley, Gennady M. Verkhivker
Mathematics, Physics, and Computer Science Faculty Articles and Research
The ongoing evolution of SARS-CoV-2 variants has underscored the need to understand not only the structural basis of antibody recognition but also the dynamic and allosteric mechanisms that could underlie complexity of broad and escape-resistant neutralization. In this study, we employed a multi-scale approach integrating structural analysis, hierarchical molecular simulations, mutational scanning and network-based allosteric modeling to dissect how Class 4 antibodies (represented by S2X35, 25F9, and SA55) and Class 5 antibodies (represented by S2H97, WRAIR-2063 and WRAIR-2134) can modulate conformational behavior, binding energetics, allosteric interactions and immune escape patterns of the SARS-CoV-2 spike protein. Using hierarchical simulations of the …
A Mutational Analysis Of Thatisin: How Single Point Mutations Impact The Biosynthetic Process Of A Group 16 Graspetide, John F. Boynton Jr
A Mutational Analysis Of Thatisin: How Single Point Mutations Impact The Biosynthetic Process Of A Group 16 Graspetide, John F. Boynton Jr
Chemistry and Chemical Biology ETDs
Abstract:
Graspetides are a family of Ribosomally synthesized and Post-translationally modified Peptide (RiPP) natural products named for their ATP Grasp Macrocyclases. We identified several Graspetide Biosynthetic Gene Clusters containing common double glycine cleavage motifs and attempted characterization of the mature Graspetides. One of the resulting peptides, Thatisin, has a topology with two interlocking macrolactones installed by a single ATP Grasp Ligase named ThtC. Here we use single and double point mutations to observe the impact or variation on the installation of these macrocycles. Alanine scan mutagenesis is used to assess leader peptide residues in the precursor peptide ThtA to determine …
Ensemble-Based Binding Free Energy Profiling And Network Analysis Of The Kras Interactions With Darpin Proteins Targeting Distinct Binding Sites: Revealing Molecular Determinants And Universal Architecture Of Regulatory Hotspots And Allosteric Binding, Mohammed Alshahrani, Vedant Parikh, Brandon Foley, Gennady M. Verkhivker
Ensemble-Based Binding Free Energy Profiling And Network Analysis Of The Kras Interactions With Darpin Proteins Targeting Distinct Binding Sites: Revealing Molecular Determinants And Universal Architecture Of Regulatory Hotspots And Allosteric Binding, Mohammed Alshahrani, Vedant Parikh, Brandon Foley, Gennady M. Verkhivker
Mathematics, Physics, and Computer Science Faculty Articles and Research
KRAS is a pivotal oncoprotein that regulates cell proliferation and survival through interactions with downstream effectors such as RAF1. Despite significant advances in understanding KRAS biology, the structural and dynamic mechanisms of KRAS allostery remain poorly understood. In this study, we employ microsecond molecular dynamics simulations, mutational scanning, and binding free energy calculations together with dynamic network modeling to dissect how engineered DARPin proteins K27, K55, K13, and K19 engage KRAS through diverse molecular mechanisms ranging from effector mimicry to conformational restriction and allosteric modulation. Mutational scanning across all four DARPin systems identifies a core set of evolutionarily constrained residues …
Molecular Insights Into The Role Of Estrogen Receptor Beta In Ecdysterone Mediated Anabolic Activity, Syeda Sumayya Tariq, Madiha Sardar, Muhammad Shafiq, Hendrick Heinz, Mohammad Nur-E-Alam, Aftab Ahmad, Zaheer Ul-Haq
Molecular Insights Into The Role Of Estrogen Receptor Beta In Ecdysterone Mediated Anabolic Activity, Syeda Sumayya Tariq, Madiha Sardar, Muhammad Shafiq, Hendrick Heinz, Mohammad Nur-E-Alam, Aftab Ahmad, Zaheer Ul-Haq
Pharmacy Faculty Articles and Research
Ecdysterone, often dubbed a “natural steroid,” has garnered significant attention among athletes for its reputed growth-promoting and anabolic properties. Unlike synthetic anabolic steroids, which are classified as controlled substances, ecdysteroids remain largely unregulated in many countries and are widely marketed as dietary supplements. Notably, ecdysterone has been included in the World Anti-Doping Agency (WADA) monitoring program, highlighting its potential impact on athletic performance and raising questions about its regulation. Emerging evidence indicates that, unlike traditional anabolic steroids that act primarily via the Androgen Receptor (AR), ecdysterone’s anabolic effects may be mediated through Estrogen Receptors (ERs), particularly Estrogen Receptor beta (ERβ). …
Integrative Computational Modeling Of Distinct Binding Mechanisms For Broadly Neutralizing Antibodies Targeting Sars-Cov-2 Spike Omicron Variants: Balance Of Evolutionary And Dynamic Adaptability In Shaping Molecular Determinants Of Immune Escape, Mohammed Alshahrani, Vedant Parikh, Brandon Foley, Gennady M. Verkhivker
Integrative Computational Modeling Of Distinct Binding Mechanisms For Broadly Neutralizing Antibodies Targeting Sars-Cov-2 Spike Omicron Variants: Balance Of Evolutionary And Dynamic Adaptability In Shaping Molecular Determinants Of Immune Escape, Mohammed Alshahrani, Vedant Parikh, Brandon Foley, Gennady M. Verkhivker
Mathematics, Physics, and Computer Science Faculty Articles and Research
In this study, we conducted a comprehensive analysis of the interactions between the receptor-binding domain (RBD) of the SARS-CoV-2 spike protein and four neutralizing antibodies—S309, S304, CYFN1006, and VIR-7229. Using integrative computational modeling that combined all-atom molecular dynamics (MD) simulations, mutational scanning, and MM-GBSA binding free energy calculations, we elucidated the structural, energetic, and dynamic determinants of antibody binding. Our findings reveal distinct dynamic binding mechanisms and evolutionary adaptation driving the broad neutralization effect of these antibodies. We show that S309 targets conserved residues near the ACE2 interface, leveraging synergistic van der Waals and electrostatic interactions, while S304 focuses on …
Probing Binding And Allosteric Mechanisms Of The Kras Interactions With Monobodies And Affimer Proteins : Ensemble-Based Mutational Profiling And Thermodynamic Analysis Of Binding Energetics And Allostery Reveal Diversity Of Functional Hotspots And Cryptic Pockets Linked By Conserved Communication Network, Mohammed Alshahrani, Vedant Parikh, Brandon Foley, Guang Hu, Gennady M. Verkhivker
Probing Binding And Allosteric Mechanisms Of The Kras Interactions With Monobodies And Affimer Proteins : Ensemble-Based Mutational Profiling And Thermodynamic Analysis Of Binding Energetics And Allostery Reveal Diversity Of Functional Hotspots And Cryptic Pockets Linked By Conserved Communication Network, Mohammed Alshahrani, Vedant Parikh, Brandon Foley, Guang Hu, Gennady M. Verkhivker
Mathematics, Physics, and Computer Science Faculty Articles and Research
KRAS, a historically "undruggable" oncogenic driver, has eluded targeted therapies due to its lack of accessible binding pockets in its active state. This study investigates the conformational dynamics, binding mechanisms, and allosteric communication networks of KRAS in complexes with monobodies (12D1, 12D5) and affimer proteins (K6, K3, K69) to characterize the binding and allosteric mechanisms and hotspots of KRAS binding. Through molecular dynamics simulations, mutational scanning, binding free energy analysis and network-based analyses, we identified conserved allosteric hotspots that serve as critical nodes for long-range communication in KRAS. Key residues in β-strand 4 (F78, L80, F82), α-helix 3 (I93, H95, …
Nifuroxazide And 4-Hydroxybenzhydrazone Derivatives As New Antiparasitic (Trypanosoma Cruzi And Leishmania Mexicana) And Anti-Mycobacterium Tuberculosis Agents, Timoteo Delgado-Maldonado, Diana V. Navarrete-Carriola, Lenci K. Vazquez-Jimenez, Alma D. Paz-Gonzalez, Baojie Wan, Scott Franzblau, Othman Mueen Mohammed, Lorena Rodríguez-Páez, Charmina Aguirre-Alvarado, Debasish Bandyopadhyay
Nifuroxazide And 4-Hydroxybenzhydrazone Derivatives As New Antiparasitic (Trypanosoma Cruzi And Leishmania Mexicana) And Anti-Mycobacterium Tuberculosis Agents, Timoteo Delgado-Maldonado, Diana V. Navarrete-Carriola, Lenci K. Vazquez-Jimenez, Alma D. Paz-Gonzalez, Baojie Wan, Scott Franzblau, Othman Mueen Mohammed, Lorena Rodríguez-Páez, Charmina Aguirre-Alvarado, Debasish Bandyopadhyay
School of Integrative Biological & Chemical Sciences Faculty Publications
Background/Objectives: Nifuroxazide (Nfz) is a drug that has been used as a scaffold for designing antimicrobial and antiparasitic agents. This study aimed to synthesize and evaluate in vitro of Nfz and twenty-five 4-hydroxybenzhydrazone derivatives as potential anti-Trypanosoma cruzi, anti-Leishmania mexicana, and anti-Mycobacterium tuberculosis agents.
Methods: The compounds were synthesized by condensing 4-hydroxybenzhydrazide with appropriate aldehydes in acidic conditions and structurally confirmed by spectroscopic techniques. All compounds were evaluated in vitro against T. cruzi strains (NINOA and A1), L. mexicana (M379 and FCQEPS strains), and M. tuberculosis (H37Rv strain), followed by enzymatic assays against T. cruzi …
Assessment Of H2s-Induced Cracking Susceptibility In Steam Line Pipes And Weld Zones During Geothermal Well Construction, Riene Kaelamanda Pragitta, Yudha Pratesa
Assessment Of H2s-Induced Cracking Susceptibility In Steam Line Pipes And Weld Zones During Geothermal Well Construction, Riene Kaelamanda Pragitta, Yudha Pratesa
Journal of Materials Exploration and Findings
The susceptibility of steam line pipes, especially in the HAZ (heat-affected zone) and weldment areas, to hydrogen sulfide in the geothermal industry is crucial to understand from the early stages, particularly during construction. The combination of tensile stress from residual stresses after welding and metallurgical phase transformation makes the joint areas vulnerable to sulfide stress cracking. This condition becomes even more extreme when the equipment operates during the well stimulation phase. This research assesses the severity of H₂S-induced cracking using NACE MR0175 and ISO 15156-1 standards, focusing on the effects of pH and partial pressure of H₂S (pH₂S …
Antiproliferative Effects Of Salvia On Breast Cancers., Allison C. Portaro
Antiproliferative Effects Of Salvia On Breast Cancers., Allison C. Portaro
College of Arts & Sciences Senior Theses
Breast cancer is the most common cancer diagnosed in female adults, with 2.3 million new cases worldwide in 2020. Plants have been used in traditional medicine and are a potential source of pharmaceuticals. One example is the large Lamiaceae (mint) family. The Salvia genus, commonly known as the sages, is the largest genus in Lamiaceae with almost 900 known species. Salvia lyrata (lyre-leaved sage) has a history of Native American medicinal use to treat cancers and other ailments resulting in this plant being referred to as ‘cancer weed.’ Extracts were produced from the leaves of S. lyrata, S. lyrata …
Mechanistic Investigation Of Ring-Opening Polymerization Of Polycaprolactone Using Tin(Ii) Catalysts: Ligand Effects And Biomedical Applications, Eva-Larue M. Barber
Mechanistic Investigation Of Ring-Opening Polymerization Of Polycaprolactone Using Tin(Ii) Catalysts: Ligand Effects And Biomedical Applications, Eva-Larue M. Barber
Honors Scholar Theses
This research explores the mechanistic aspects of ring-opening polymerization (ROP) of ε-caprolactone (CL) to produce polycaprolactone (PCL), a biodegradable polymer widely used in biomedical applications. The study investigates how light exposure and catalyst concentration influence polymerization efficiency, using tin(II) 2-ethylhexanoate [Sn(Oct)₂] as the catalyst in a non-polar toluene solvent at 90 °C. Reactions were conducted under either ambient light or black light bulb (BLB) illumination, with monomer-to-catalyst ratios of 1:1 and 200:1.
Proton nuclear magnetic resonance (¹H NMR) spectroscopy was used to analyze conversion efficiency by tracking the disappearance of monomer signals and appearance of characteristic PCL peaks. Results revealed …
Biophysical Studies Of Nucleic Acid - Small Molecule Recognition, Andrea Conner
Biophysical Studies Of Nucleic Acid - Small Molecule Recognition, Andrea Conner
All Dissertations
The presented work is a collection of studies performed to examine small molecule recognition of nucleic acids. Recognition of nucleic acids was examined using two types of small molecules: aminoglycosides and Hoechst dyes. Chapter One focuses on established experimental techniques (i.e. absorbance, isothermal titration calorimetry, flow cytometry, cell microscopy, etc.) in small molecule recognition of nucleic acids. The emphasis of studies in the group has been on two focus areas. (i) Thermodynamic characterization of mixed A-form and B-form DNA or RNA conformation with aminoglycosides, particularly neomycin-class. (ii) Characterization of new Hoechst-morpholine (HT-MO) derivatives’ interactions with nucleic acids.
Focus area (i) …
The Analysis Of Reference Standard Storage Failures Through The Use Of Ibuprofen, Hope Vonder Brink
The Analysis Of Reference Standard Storage Failures Through The Use Of Ibuprofen, Hope Vonder Brink
Honors Projects
Reference standards are commonly used in drug chemistry. They are used to calibrate the instruments and serve as a known point of reference for analysts’ ability to compare unknowns. Drugs can degrade over time or through environmental factors, causing contaminants to be present. In the event of environmental degradation while in storage, such as the exposure to high heat, it would be beneficial to have a database of known breakdown products in common drug reference standards for analysts’ reference. Using ibuprofen as an exemplar drug, this study attempted to identify the thermal breakdown products of ibuprofen and introduce the proposed …
Quantitative Characterization And Prediction Of The Binding Determinants And Immune Escape Hotspots For Groups Of Broadly Neutralizing Antibodies Against Omicron Variants: Atomistic Modeling Of The Sars-Cov-2 Spike Complexes With Antibodies, Mohammed Alshahrani, Vedant Parikh, Brandon Foley, Nishank Raisinghani, Gennady M. Verkhivker
Quantitative Characterization And Prediction Of The Binding Determinants And Immune Escape Hotspots For Groups Of Broadly Neutralizing Antibodies Against Omicron Variants: Atomistic Modeling Of The Sars-Cov-2 Spike Complexes With Antibodies, Mohammed Alshahrani, Vedant Parikh, Brandon Foley, Nishank Raisinghani, Gennady M. Verkhivker
Mathematics, Physics, and Computer Science Faculty Articles and Research
A growing body of experimental and computational studies suggests that the cross-neutralization antibody activity against Omicron variants may be driven by the balance and tradeoff between multiple energetic factors and interaction contributions of the evolving escape hotspots involved in antigenic drift and convergent evolution. However, the dynamic and energetic details quantifying the balance and contribution of these factors, particularly the balancing nature of specific interactions formed by antibodies with epitope residues, remain largely uncharacterized. In this study, we performed molecular dynamics simulations, an ensemble-based deep mutational scanning of SARS-CoV-2 spike residues, and binding free energy computations for two distinct groups …
Determination Of Structural Factors Contributing To Protection Of Zinc Fingers In Estrogen Receptor Α Through Molecular Dynamic Simulations, Patricia B. Lutz, Wesley R. Coombs, Craig A. Bayse
Determination Of Structural Factors Contributing To Protection Of Zinc Fingers In Estrogen Receptor Α Through Molecular Dynamic Simulations, Patricia B. Lutz, Wesley R. Coombs, Craig A. Bayse
Chemistry & Biochemistry Faculty Publications
The ERα transcription factor that induces tumor growth is a potential target for breast cancer treatment. Each monomer of the ERα DNA-binding domain (ERαDBD) homodimer has two conserved (Cys)4-type zinc fingers, ZF1 (N-terminal) and ZF2 (C-terminal). Electrophilic agents release Zn2+ by oxidizing the coordinating Cys of the more labile ZF2 to inhibit dimerization and DNA binding. Microsecond-length molecular dynamics (MD) simulations show that greater flexibility of ZF2 in the ERαDBD monomer leaves its Cys more solvent accessible and less shielded from electrophilic attack by sulfur-centered hydrogen bonds than ZF1 which is buried in the protein. In the …
Phytochemical Analysis, Antioxidant, And Antibacterial Properties Of Partition Fractions Of Adansonia Digitata And Annona Muricata Extracts Using Chloroform, Ethyl Acetate, Ethanol, And Aqueous Solvent Systems, Fagbohun Oyenike Bushirat, Hassan Abdusalam Adewuyi, Sakariyau Adio Waheed, Maryam Nana Musa, Timothy God-Giveth Olusegun, Ayomide Babatunde Ishola, Agumage Idoko, Adeola Victor Kolawole, Adesanmi Adefunmilayo Oluwatuyi, Sarah Ngozi Agwasim
Phytochemical Analysis, Antioxidant, And Antibacterial Properties Of Partition Fractions Of Adansonia Digitata And Annona Muricata Extracts Using Chloroform, Ethyl Acetate, Ethanol, And Aqueous Solvent Systems, Fagbohun Oyenike Bushirat, Hassan Abdusalam Adewuyi, Sakariyau Adio Waheed, Maryam Nana Musa, Timothy God-Giveth Olusegun, Ayomide Babatunde Ishola, Agumage Idoko, Adeola Victor Kolawole, Adesanmi Adefunmilayo Oluwatuyi, Sarah Ngozi Agwasim
Chemistry & Biochemistry Faculty Publications
Adansonia digitata and Annona muricata are traditionally used medicinal plants with reported pharmacological properties. In this study, we aimed to elucidate the phytochemical composition, antioxidant activity, and antibacterial properties of partition fractions of Adansonia digitata and Annona muricata extracts obtained using chloroform, ethyl acetate, ethanol, and aqueous solvent systems. The plant extracts were successively partitioned using chloroform, ethyl acetate, ethanol, and aqueous solvent systems. Phytochemical analysis was performed using standard methods. Antioxidant activity was evaluated using FRAP and DPPH assays. Antibacterial activity was assessed using agar well diffusion and MIC determination. Phytochemical analysis revealed the presence of alkaloids (10.2-15.6%), flavonoids …
The Importance Of Atomic Charges For Predicting Site-Selective Ir-, Ru-, And Rh-Catalyzed C-H Borylations, Shannon M. Stephens, Kyle M. Lambert
The Importance Of Atomic Charges For Predicting Site-Selective Ir-, Ru-, And Rh-Catalyzed C-H Borylations, Shannon M. Stephens, Kyle M. Lambert
Chemistry & Biochemistry Faculty Publications
A supervised machine learning model has been developed that allows for the prediction of site selectivity in late-stage C-H borylations. Model development was accomplished using literature data for the site-selective (≥95%) C-H borylation of 189 unique arene, heteroarene, and aliphatic substrates that feature a total of 971 possible sp² or sp³ C-H borylation sites. The reported experimental data was supplemented with additional chemoinformatic descriptors, computed atomic charges at the C-H borylation sites, and data from parameterization of catalytically active tris-boryl complexes resulting from the combination of seven different Ir-, Ru-, and Rh-based precatalysts with eight different ligands. Of the over …
Modified N-Heterocyclic Carbene Catalysts For Polyurethane Synthesis, Charise D. Young
Modified N-Heterocyclic Carbene Catalysts For Polyurethane Synthesis, Charise D. Young
Pomona Senior Theses
Polyurethanes are widely used polymers synthesized from diisocyanate and diol molecules. They are ubiquitous polymeric materials with important industrial applications. Their increasing market value prompts the need for selective and efficient production which can be achieved through N-Heterocyclic carbene (NHC) catalysis. N-heterocyclic carbenes are heterocyclic molecules containing a carbene atom and at least one nitrogen adjacent to the carbene center. The nitrogen substituents on the adjacent nitrogen play an important role in influencing their steric and electronic properties and resultant reactivity.1,2 There is a lack of a comprehensive understanding of the steric and electronic properties of NHCs and how …
Rwanda's Natural Remedies: A Fresh Look At The Fight Against Malaria, Leandre Nsabimana Ndisanze
Rwanda's Natural Remedies: A Fresh Look At The Fight Against Malaria, Leandre Nsabimana Ndisanze
Pomona Senior Theses
Malaria remains one of the most devastating parasitic diseases globally, disproportionately affecting sub-Saharan Africa, where Rwanda continues to face high transmission rates and rising resistance to conventional interventions. Despite decades of control efforts, the emergence of drug-resistant Plasmodium falciparum and insecticide-resistant Anopheles mosquitoes threatens to reverse recent gains. This research responds to the urgent need for sustainable and culturally relevant alternatives by exploring the therapeutic potential of Rwandan traditional medicinal plants. These indigenous remedies, long used by local healers, offer an underexplored reservoir of bioactive compounds that may provide the basis for novel antimalarial drugs.
The central hypothesis of this …
A Comparison Of Microcrystal Electron Diffraction And X-Ray Powder Diffraction For The Structural Analysis Of Metal-Organic Frameworks, Erik Biehler, Silvana Pagola, Daniel Stam, Johannes Merkelbach, Christian Jandl, Tarek M. Abdel-Fattah
A Comparison Of Microcrystal Electron Diffraction And X-Ray Powder Diffraction For The Structural Analysis Of Metal-Organic Frameworks, Erik Biehler, Silvana Pagola, Daniel Stam, Johannes Merkelbach, Christian Jandl, Tarek M. Abdel-Fattah
Chemistry & Biochemistry Faculty Publications
This study successfully implemented microcrystal electron diffraction (microED) and X-ray powder diffraction (XRPD) for the crystal structure determination of a new phase, TAF-CNU-1, Ni(C₈H₄O₄)·3H₂O, solved by microED from single microcrystals in the powder and refined at the kinematic and dynamic electron diffraction theory levels. This nickel metal–organic framework (MOF), together with its cobalt and manganese analogues with formula M (C₈H₄O₄)·2H₂O with M = Mn II or CoII, were synthesized in aqueous media as one-pot preparations from the corresponding hydrated metal chlorides and sodium terephthalate, as a promising `green' synthetic route to moisture-stable MOFs. The crystal structures of the …
Deciphering The Chemistry Of Condensed Aromatic "Black" Carbon And Nitrogen In Amazonian Anthrosols, João Vitor Dos Santos, Aleksandar I. Goranov, Laís G. Fregolente, Marcia C. Bisinoti, Zhenhuan Sun, Klaus Schmidt-Rohr, Patrick G. Hatcher
Deciphering The Chemistry Of Condensed Aromatic "Black" Carbon And Nitrogen In Amazonian Anthrosols, João Vitor Dos Santos, Aleksandar I. Goranov, Laís G. Fregolente, Marcia C. Bisinoti, Zhenhuan Sun, Klaus Schmidt-Rohr, Patrick G. Hatcher
Chemistry & Biochemistry Faculty Publications
Amazonian anthrosols are renowned for their high fertility and dark color, properties primarily attributed to the abundance of condensed aromatic carbon (ConAC) in the soil organic matter. ConAC, commonly referred to as black carbon, play a key role in the stability and nutrient retention of these soils. However, the processes governing the formation of ConAC and its transformation into oxygenated derivatives remain poorly understood. In this study, we used multiple analytical platforms to investigate the chemistry of ConAC-rich humic acids (HA) extracted from Terra Mulata de Indio, a type of Amazonian anthrosol. The results reveal that ConAC are predominantly …
Towards Developing Glut2 Specific Probes For Biochemical And Biomedical Applications, Abdelrahman Ismail
Towards Developing Glut2 Specific Probes For Biochemical And Biomedical Applications, Abdelrahman Ismail
Dissertations, Master's Theses and Master's Reports
Facilitated Glucose transporters (GLUTs) are membrane proteins responsible for the uptake of simple sugars and other structurally similar metabolites in all mammalian cells. One of the hallmarks of cancer is dysfunctional sugar metabolism, known as the Warburg effect, and one of the manifestations of that effect is abnormal GLUT expression. There are 14 known GLUT proteins with different expression patterns in different tissues, and tumors tend to express certain GLUTs that are not present in surrounding healthy tissue. Therefore, selective targeting of GLUTs presents a potentially powerful tool for diagnostics and treatment of cancer and other diseases. This has been …
Alpha-Synuclein Interaction With Gedunin, Tony Matundura Nyabayo
Alpha-Synuclein Interaction With Gedunin, Tony Matundura Nyabayo
Graduate Theses/Dissertations
Parkinson’s disease (PD) and other Proteinopathies develop when α-synuclein misfolds and aggregates into toxic amyloids. While existing treatments for PD are primarily focused on managing its symptoms, a viable solution for slowing down the progress of Parkinson’s disease involves targeting the toxic α-synuclein amyloids. Gedunin, a natural inhibitor of heat shock protein 90, has been extensively used to treat malaria. Also, recent research investigations have shed light on its potential beyond malaria therapy, indicating that Gedunin may offer a possible solution for treating a variety of neurodegenerative diseases. Using plate-based assays, we examined how Gedunin influences α-synuclein fibrillation and its …
Interaction Of Cardiac Leiomodin With The Native Cardiac Thin Filament, Madison Little, Cristina M. Risi, Tania M. Larrinaga, Mason D. Summers, Tyler Nguyen, Garry E. Smith Jr., Jennifer Atherton, Carol C. Gregorio, Alla S. Kostyukova, Vitold E. Galkin
Interaction Of Cardiac Leiomodin With The Native Cardiac Thin Filament, Madison Little, Cristina M. Risi, Tania M. Larrinaga, Mason D. Summers, Tyler Nguyen, Garry E. Smith Jr., Jennifer Atherton, Carol C. Gregorio, Alla S. Kostyukova, Vitold E. Galkin
Department of Biomedical and Translational Sciences Faculty Publications
Every heartbeat depends on cyclical contraction-relaxation produced by the interactions between myosin-containing thick and actin-based thin filaments (TFs) arranged into a crystalline-like lattice in the cardiac sarcomere. Therefore, the maintenance of thin filament length is crucial for myocardium function. The thin filament is comprised of an actin backbone, the regulatory troponin complex and tropomyosin that controls interactions between thick and thin filaments. Thin filament length is controlled by the tropomodulin family of proteins; tropomodulin caps pointed ends of thin filaments, and leiomodin (Lmod) promotes elongation of thin filaments by a “leaky-cap” mechanism. The broader distribution of Lmod on the thin …