Open Access. Powered by Scholars. Published by Universities.®

Physical Sciences and Mathematics Commons

Open Access. Powered by Scholars. Published by Universities.®

Articles 1 - 30 of 54

Full-Text Articles in Physical Sciences and Mathematics

Impact Of Pulsed Electric Field Treatment On Barley Germination For Malting, Rose Saxton, Caitlin Lahey, Brianna Smith, Emily Hibberd, Joshua Bevan, Cini Baumhoff, Ashley Galant, Jerry Young, Brian Meyer, Owen M. Mcdougal Apr 2024

Impact Of Pulsed Electric Field Treatment On Barley Germination For Malting, Rose Saxton, Caitlin Lahey, Brianna Smith, Emily Hibberd, Joshua Bevan, Cini Baumhoff, Ashley Galant, Jerry Young, Brian Meyer, Owen M. Mcdougal

Chemistry and Biochemistry Faculty Publications and Presentations

The malting process takes one week to steep, germinate, and kiln barley to make malt. Making quality malt is critically important to achieve the desired attributes of the finished beer, and the process is time-intensive and costly. Malt quality is assessed by indicators including β-glucan quantity, α-amylase activity, Free Amino Nitrogen (FAN) content, and overall extract concentration in the finished malt. Here, we report Pulsed Electric Field (PEF) treatment of barley to accelerate malt production. A small-scale trial of 250 g to 1.00 kg barley, was evaluated for germination at two PEF treatment conditions, generically referred to as “low” and …


Determining The Surface PKA Of Perfluorooctanoic Acid, Lila J. Musegades, Owen P. Curtin, Jenée D. Cyran Feb 2024

Determining The Surface PKA Of Perfluorooctanoic Acid, Lila J. Musegades, Owen P. Curtin, Jenée D. Cyran

Chemistry and Biochemistry Faculty Publications and Presentations

Perfluorooctanoic acid (PFOA) is an environmentally prevalent and persistent organic pollutant with toxic and bioaccumulative properties. Despite the known importance of perfluorinated pollutants in the global environment, molecular-level details of the physicochemical behavior of PFOA on aqueous interfaces remain poorly understood. Here, we utilized two surface-specific techniques, vibrational sum frequency generation spectroscopy (SFG) and surface tensiometry, to investigate the pH-induced structural changes of PFOA and octanoic acid (OA) and determined the apparent pKa at the air–water surface. The SFG spectra and surface activity model were investigated over a wide range of pHs. With the surface tension measurements, the …


Pharmacology Of Veratrum Californicum Alkaloids As Hedgehog Pathway Antagonists, Madison L. Dirks, Owen M. Mcdougal Jan 2024

Pharmacology Of Veratrum Californicum Alkaloids As Hedgehog Pathway Antagonists, Madison L. Dirks, Owen M. Mcdougal

Chemistry and Biochemistry Faculty Publications and Presentations

Veratrum californicum contains steroidal alkaloids that function as inhibitors of hedgehog (Hh) signaling, a pathway involved in the growth and differentiation of cells and normal tissue development. This same Hh pathway is abnormally active for cell proliferation in more than 20 types of cancer. In this current study, alkaloids have been extracted from the root and rhizome of V. californicum, followed by their separation into five fractions using high performance liquid chromatography. Mass spectrometry was used to identify the presence of twenty-five alkaloids, nine more than are commonly cited in literature reports, and the Bruker Compass Data Analysis software …


Functional Aggregation Of Cell-Free Proteins Enables Fungal Ice Nucleation, Ralph Schwidetzky, Ingrid De Almeida Ribeiro, Nadine Bothen, Anna T. Backes, Arthur L. Devries, Mischa Bonn, Janine Fröhlich-Nowoisky, Valeria Molinero, Konrad Meister Nov 2023

Functional Aggregation Of Cell-Free Proteins Enables Fungal Ice Nucleation, Ralph Schwidetzky, Ingrid De Almeida Ribeiro, Nadine Bothen, Anna T. Backes, Arthur L. Devries, Mischa Bonn, Janine Fröhlich-Nowoisky, Valeria Molinero, Konrad Meister

Chemistry and Biochemistry Faculty Publications and Presentations

Biological ice nucleation plays a key role in the survival of cold-adapted organisms. Several species of bacteria, fungi, and insects produce ice nucleators (INs) that enable ice formation at temperatures above −10 °C. Bacteria and fungi produce particularly potent INs that can promote water crystallization above −5 °C. Bacterial INs consist of extended protein units that aggregate to achieve superior functionality. Despite decades of research, the nature and identity of fungal INs remain elusive. Here, we combine ice nucleation measurements, physicochemical characterization, numerical modeling, and nucleation theory to shed light on the size and nature of the INs from the …


Quantification Of Anion And Cation Uptake In Ice Ih Crystals, Tiara Sivells, Pranav Viswanathan, Jenée D. Cyran Apr 2023

Quantification Of Anion And Cation Uptake In Ice Ih Crystals, Tiara Sivells, Pranav Viswanathan, Jenée D. Cyran

Chemistry and Biochemistry Faculty Publications and Presentations

While ice has very low solubility for salts compared to water, small amounts of ions are doped into ice crystals. These small ion dopants can alter the fundamental physical and chemical properties of ice, such as its structure and electrical conductivity. Therefore, these results could have a direct impact on the chemical reactivity of ice and ice surfaces. Here, we examine the influence of the uptake of three salts—ammonium chloride (NH4Cl), sodium chloride (NaCl), and ammonium sulfate [(NH4)2SO4]—on ice Ih formation using capillary electrophoresis. Using both cation and anion modes, we observed …


Veratrum Parviflorum Poisoning: Identification Of Steroidal Alkaloids In Patient Blood And Breast Milk, Jared T. Seale, Xinzhu Pu, Owen M. Mcdougal Dec 2022

Veratrum Parviflorum Poisoning: Identification Of Steroidal Alkaloids In Patient Blood And Breast Milk, Jared T. Seale, Xinzhu Pu, Owen M. Mcdougal

Chemistry and Biochemistry Faculty Publications and Presentations

Introduction

The Veratrum genus is composed of plants containing a diverse set of steroidal alkaloids. Veratrum plant material has been utilized for centuries as herbal medicines, however the alkaloids have such a low therapeutic index that they are not used in modern medicine. Here we report an incident of inadvertent ingestion of V. parviflorum by hikers in Georgia that allowed detection, and in several instances identification of alkaloids from the plant, and correlated their presence within patient blood and breast milk specimens.

Case history

Eight patients, three male and five female, presented in the spring of 2020 and 2021 with …


Symmetry Breaking Charge Transfer In Dna-Templated Perylene Dimer Aggregates, Katelyn M. Duncan, Donald L. Kellis, Jonathan S. Huff, Matthew S. Barclay, Jeunghoon Lee, Daniel B. Turner, Paul H. Davis, Bernard Yurke, William B. Knowlton, Ryan D. Pensack Oct 2022

Symmetry Breaking Charge Transfer In Dna-Templated Perylene Dimer Aggregates, Katelyn M. Duncan, Donald L. Kellis, Jonathan S. Huff, Matthew S. Barclay, Jeunghoon Lee, Daniel B. Turner, Paul H. Davis, Bernard Yurke, William B. Knowlton, Ryan D. Pensack

Chemistry and Biochemistry Faculty Publications and Presentations

Molecular aggregates are of interest to a broad range of fields including light harvesting, organic optoelectronics, and nanoscale computing. In molecular aggregates, nonradiative decay pathways may emerge that were not present in the constituent molecules. Such nonradiative decay pathways may include singlet fission, excimer relaxation, and symmetry-breaking charge transfer. Singlet fission, sometimes referred to as excitation multiplication, is of great interest to the fields of energy conversion and quantum information. For example, endothermic singlet fission, which avoids energy loss, has been observed in covalently bound, linear perylene trimers and tetramers. In this work, the electronic structure and excited-state dynamics of …


Context And Content Of Teaching Conversations: Exploring How To Promote Sharing Of Innovative Teaching Knowledge Between Science Faculty, Brittnee Earl, Karl Mertens, Susan E. Shadle, John P. Ziker Aug 2022

Context And Content Of Teaching Conversations: Exploring How To Promote Sharing Of Innovative Teaching Knowledge Between Science Faculty, Brittnee Earl, Karl Mertens, Susan E. Shadle, John P. Ziker

Chemistry and Biochemistry Faculty Publications and Presentations

Background: Change strategies may leverage interpersonal relationships and conversations to spread teaching innovations among science faculty. Knowledge sharing refers to the process by which individuals transfer information and thereby spread innovative ideas within an organization. We use knowledge sharing as a lens for identifying factors that encourage productive teaching-related conversations between individuals, characterizing the context and content of these discussions, and understanding how peer interactions may shape instructional practices. In this study, we interview 19 science faculty using innovative teaching practices about the teaching-focused conversations they have with diferent discussion partners.

Results: This qualitative study describes characteristics of the relationship …


Veratrum Parviflorum: An Underexplored Source For Bioactive Steroidal Alkaloids, Jared T. Seale, Owen M. Mcdougal Aug 2022

Veratrum Parviflorum: An Underexplored Source For Bioactive Steroidal Alkaloids, Jared T. Seale, Owen M. Mcdougal

Chemistry and Biochemistry Faculty Publications and Presentations

Plants of the Veratrum genus have been used throughout history for their emetic properties, rheumatism, and for the treatment of high blood pressure. However, inadvertent consumption of these plants, which resemble wild ramps, induces life-threatening side effects attributable to an abundance of steroidal alkaloids. Several of the steroidal alkaloids from Veratrum spp. have been investigated for their ability to antagonize the Hedgehog (Hh) signaling pathway, a key pathway for embryonic development and cell proliferation. Uncontrolled activation of this pathway is linked to the development of various cancers; most notably, basal cell carcinoma and acute myeloid leukemia. Additional investigation of Veratrum …


Photocrosslinking Probes Proximity Of Thymine Modifiers Tethering Excitonically Coupled Dye Aggregates To Dna Holliday Junction, Shibani Basu, Keitel Cervantes-Salguero, Bernard Yurke, William B. Knowlton, Jeunghoon Lee, Olga A. Mass Jul 2022

Photocrosslinking Probes Proximity Of Thymine Modifiers Tethering Excitonically Coupled Dye Aggregates To Dna Holliday Junction, Shibani Basu, Keitel Cervantes-Salguero, Bernard Yurke, William B. Knowlton, Jeunghoon Lee, Olga A. Mass

Chemistry and Biochemistry Faculty Publications and Presentations

A DNA Holliday junction (HJ) has been used as a versatile scaffold to create a variety of covalently templated molecular dye aggregates exhibiting strong excitonic coupling. In these dye-DNA constructs, one way to attach dyes to DNA is to tether them via single long linkers to thymine modifiers incorporated in the core of the HJ. Here, using photoinduced [2 + 2] cycloaddition (photocrosslinking) between thymines, we investigated the relative positions of squaraine-labeled thymine modifiers in the core of the HJ, and whether the proximity of thymine modifiers correlated with the excitonic coupling strength in squaraine dimers. Photocrosslinking between squaraine-labeled thymine …


Fortilin Interacts With Tgf-Β1 And Prevents Tgf-Β Receptor Activation, Decha Pinkaew, Erik Martinez-Hackert, Wei Jia, Matthew D. King, Fei Miao, Nicole R. Enger, Runglawan Silakit, Kota Ramana, Shi-You Chen, Ken Fujise Feb 2022

Fortilin Interacts With Tgf-Β1 And Prevents Tgf-Β Receptor Activation, Decha Pinkaew, Erik Martinez-Hackert, Wei Jia, Matthew D. King, Fei Miao, Nicole R. Enger, Runglawan Silakit, Kota Ramana, Shi-You Chen, Ken Fujise

Chemistry and Biochemistry Faculty Publications and Presentations

Fortilin is a 172-amino acid multifunctional protein present in both intra- and extracellular spaces. Although fortilin binds and regulates various cellular proteins, the biological role of extracellular fortilin remains unknown. Here we report that fortilin specifically interacts with TGF-β1 and prevents it from activating the TGF-β1 signaling pathway. In a standard immunoprecipitation-western blot assay, fortilin co-immunoprecipitates TGF-β1 and its isoforms. The modified ELISA assay shows that TGF-β1 remains complexed with fortilin in human serum. Both bio-layer interferometry and surface plasmon resonance (SPR) reveal that fortilin directly bind TGF-β1. The SPR analysis also reveals that fortilin and the TGF-β receptor II …


Expression And Purification Of A Cleavable Recombinant Fortilin From Escherichia Coli For Structure Activity Studies, Maranda S. Cantrell, Jackson D. Wall, Xinzhu Pu, Matthew Turner, Luke Woodbury, Owen M. Mcdougal, Lisa R. Warner Jan 2022

Expression And Purification Of A Cleavable Recombinant Fortilin From Escherichia Coli For Structure Activity Studies, Maranda S. Cantrell, Jackson D. Wall, Xinzhu Pu, Matthew Turner, Luke Woodbury, Owen M. Mcdougal, Lisa R. Warner

Chemistry and Biochemistry Faculty Publications and Presentations

Complications related to atherosclerosis account for approximately 1 in 4 deaths in the United States and treatment has focused on lowering serum LDL-cholesterol levels with statins. However, approximately 50% of those diagnosed with atherosclerosis have blood cholesterol levels within normal parameters. Human fortilin is an anti-apoptotic protein and a factor in macrophage-mediated atherosclerosis and is hypothesized to protect inflammatory macrophages from apoptosis, leading to subsequent cardiac pathogenesis. Fortilin is unique because it provides a novel drug target for atherosclerosis that goes beyond lowering cholesterol and utilization of a solution nuclear magnetic resonance (NMR) spectroscopy, structure-based drug discovery approach requires milligram …


A Modular Strategy For Expanding Electron-Sink Capacity In Noncanonical Cluster Assemblies, Yume Mai, Alexandria K. Balzen, Rebecca K. Torren, Michael P. Callahan, Adam C. Colson Dec 2021

A Modular Strategy For Expanding Electron-Sink Capacity In Noncanonical Cluster Assemblies, Yume Mai, Alexandria K. Balzen, Rebecca K. Torren, Michael P. Callahan, Adam C. Colson

Chemistry and Biochemistry Faculty Publications and Presentations

A modular synthetic strategy is described whereby organometallic complexes exhibiting considerable electron-sink capacity may be assembled by using only a few simple molecular components. The Fe2(PPh2)2(CO)5 fragment was selected as a common electroactive component and was assembled around aromatic cores bearing one, two, or three isocyanide functional groups, with the resultant complexes possessing electron-sink capacities of two, four, and six electrons, respectively. The latter complex is noteworthy in that its electron-sink capacity was found to rival that of large multinuclear clusters (e.g., [Ni32C6(CO)36]6– and [Ni38 …


Review: Veratrum Californicum Alkaloids, Madison L. Dirks, Jared T. Seale, Joseph M. Collins, Owen M. Mcdougal Oct 2021

Review: Veratrum Californicum Alkaloids, Madison L. Dirks, Jared T. Seale, Joseph M. Collins, Owen M. Mcdougal

Chemistry and Biochemistry Faculty Publications and Presentations

Veratrum spp. grow throughout the world and are especially prevalent in high mountain meadows of North America. All parts of Veratrum plants have been used for the treatment of ailments including injuries, hypertension, and rheumatic pain since as far back as the 1600s. Of the 17–45 Veratrum spp., Veratrum californicum alkaloids have been proven to possess favorable medicinal properties associated with inhibition of hedgehog (Hh) pathway signaling. Aberrant Hh signaling leads to proliferation of over 20 cancers, including basal cell carcinoma, prostate and colon among others. Six of the most well-studied V. californicum alkaloids are cyclopamine (1), veratramine (2) …


Instrumentation For Routine Analysis Of Acrylamide In French Fries: Assessing Limitations For Adoption, Mark M. Skinner, Jared T. Seale, Maranda S. Cantrell, Joseph M. Collins, Matthew W. Turner, Owen M. Mcdougal Sep 2021

Instrumentation For Routine Analysis Of Acrylamide In French Fries: Assessing Limitations For Adoption, Mark M. Skinner, Jared T. Seale, Maranda S. Cantrell, Joseph M. Collins, Matthew W. Turner, Owen M. Mcdougal

Chemistry and Biochemistry Faculty Publications and Presentations

The purpose of this experimental review was to detect acrylamide in French fries using methods most adaptable to the food process industry for quality control assessment of products. French fries were prepared at different cook times using the same fryer oil over a five-day period to assess the influence of oil degradation and monitor trends in acrylamide formation. Acrylamide detection was performed using LC-MS, GC-MS and FT-NIR. The low levels of acrylamide produced during frying, low molecular weight of the analyte, and complexity of the potato matrix make routine acrylamide measurement challenging in a well-outfitted analytical lab with trained personnel. …


Repurposing Drugs To Treat Heart And Brain Illness, Maranda S. Cantrell, Alejandro Soto-Avellaneda, Jackson D. Wall, Aaron D. Ajeti, Brad E. Morrison, Lisa R. Warner, Owen M. Mcdougal Jun 2021

Repurposing Drugs To Treat Heart And Brain Illness, Maranda S. Cantrell, Alejandro Soto-Avellaneda, Jackson D. Wall, Aaron D. Ajeti, Brad E. Morrison, Lisa R. Warner, Owen M. Mcdougal

Chemistry and Biochemistry Faculty Publications and Presentations

Drug development is a complicated, slow and expensive process with high failure rates. One strategy to mitigate these factors is to recycle existing drugs with viable safety profiles and have gained Food and Drug Administration approval following extensive clinical trials. Cardiovascular and neurodegenerative diseases are difficult to treat, and there exist few effective therapeutics, necessitating the development of new, more efficacious drugs. Recent scientific studies have led to a mechanistic understanding of heart and brain disease progression, which has led researchers to assess myriad drugs for their potential as pharmacological treatments for these ailments. The focus of this review is …


Post Covid-19 Water And Waste Water Management To Protect Public Health And Geoenvironment, Ken Cornell, Arvin Farid May 2021

Post Covid-19 Water And Waste Water Management To Protect Public Health And Geoenvironment, Ken Cornell, Arvin Farid

Chemistry and Biochemistry Faculty Publications and Presentations

The coronavirus disease 2019 pandemic has posed severe threats to humans and the geoenvironment. The findings of severe acute respiratory syndrome coronavirus 2 (Sars-CoV-2) traces in waste water and the practice of disinfecting outdoor spaces in several cities in the world, which can result into the entry of disinfectants and their by-products into storm drainage systems and their subsequent discharge into rivers and coastal waters, raise the issue of environmental, ecological and public health effects. The aims of the current paper are to investigate the potential of water and waste water to operate as transmission routes for Sars-CoV-2 and the …


Rotaxane Rings Promote Oblique Packing And Extended Lifetimes In Dna-Templated Molecular Dye Aggregates, Matthew S. Barclay, Simon K. Roy, Jonathan S. Huff, Olga A. Mass, Daniel B. Turner, Christopher K. Wilson, Donald L. Kellis, Jeunghoon Lee, Paul H. Davis, Bernard Yurke, William B. Knowlton, Ryan D. Pensack Feb 2021

Rotaxane Rings Promote Oblique Packing And Extended Lifetimes In Dna-Templated Molecular Dye Aggregates, Matthew S. Barclay, Simon K. Roy, Jonathan S. Huff, Olga A. Mass, Daniel B. Turner, Christopher K. Wilson, Donald L. Kellis, Jeunghoon Lee, Paul H. Davis, Bernard Yurke, William B. Knowlton, Ryan D. Pensack

Chemistry and Biochemistry Faculty Publications and Presentations

Molecular excitons play a central role in natural and artificial light harvesting, organic electronics, and nanoscale computing. The structure and dynamics of molecular excitons, critical to each application, are sensitively governed by molecular packing. Deoxyribonucleic acid (DNA) templating is a powerful approach that enables controlled aggregation via sub-nanometer positioning of molecular dyes. However, finer sub-Angstrom control of dye packing is needed to tailor excitonic properties for specific applications. Here, we show that adding rotaxane rings to squaraine dyes templated with DNA promotes an elusive oblique packing arrangement with highly desirable optical properties. Specifically, dimers of these squaraine:rotaxanes exhibit an absorption …


1,4,5,8-Naphthalene Tetracarboxylate Dianhydride/G-C3N4 Van Der Waals Heterojunctions Exhibit Enhanced Photochemical H2O2 Production And Antimicrobial Activity, John H. Thurston, Molly Vitale-Sullivan, Azhar Koshkimbayeva, Tyler R. Smith, Kenneth A. Cornell Jan 2021

1,4,5,8-Naphthalene Tetracarboxylate Dianhydride/G-C3N4 Van Der Waals Heterojunctions Exhibit Enhanced Photochemical H2O2 Production And Antimicrobial Activity, John H. Thurston, Molly Vitale-Sullivan, Azhar Koshkimbayeva, Tyler R. Smith, Kenneth A. Cornell

Chemistry and Biochemistry Faculty Publications and Presentations

Organic semiconductors, including graphitic carbon nitride (g-C3N4, CN), represent an important class of materials for the development of novel antimicrobial or biomedical technologies. Of principal interest is the ability of these materials to catalyze the reduction of elemental oxygen to generate reactive oxygen species (ROS), including hydrogen peroxide (H2O2). Here, we describe the fabrication of photoactive van der Waals heterojunctions incorporating 1,4,5,8-naphthalene tetracarboxylic dianhydride (NTCDA) and CN. The composite heterojunction systems were characterized by a combination of physical (TEM, SEM, pXRD), spectroscopic (FT-IR, XPS, DRUV, photoluminescence, TCSPC) and kinetic experiments. Electronic interactions …


Ribbon Α-Conotoxin Ktm Exhibits Potent Inhibition Of Nicotinic Acetylcholine Receptors, Leanna A. Marquart, Matthew W. Turner, Lisa R. Warner, Matthew D. King, James R. Groome, Owen M. Mcdougal Dec 2019

Ribbon Α-Conotoxin Ktm Exhibits Potent Inhibition Of Nicotinic Acetylcholine Receptors, Leanna A. Marquart, Matthew W. Turner, Lisa R. Warner, Matthew D. King, James R. Groome, Owen M. Mcdougal

Chemistry and Biochemistry Faculty Publications and Presentations

KTM is a 16 amino acid peptide with the sequence WCCSYPGCYWSSSKWC. Here, we present the nuclear magnetic resonance (NMR) structure and bioactivity of this rationally designed α-conotoxin (α-CTx) that demonstrates potent inhibition of rat α3β2-nicotinic acetylcholine receptors (rα3β2-nAChRs). Two bioassays were used to test the efficacy of KTM. First, a qualitative PC12 cell-based assay confirmed that KTM acts as a nAChR antagonist. Second, bioactivity evaluation by two-electrode voltage clamp electrophysiology was used to measure the inhibition of rα3β2-nAChRs by KTM (IC50 = 0.19 ± 0.02 nM), and inhibition of the same nAChR isoform by α-CTx MII (IC50 = …


Qualitative Assay To Detect Dopamine Release By Ligand Action On Nicotinic Acetylcholine Receptors, Leanna A. Marquart, Matthew W. Turner, Owen M. Mcdougal Dec 2019

Qualitative Assay To Detect Dopamine Release By Ligand Action On Nicotinic Acetylcholine Receptors, Leanna A. Marquart, Matthew W. Turner, Owen M. Mcdougal

Chemistry and Biochemistry Faculty Publications and Presentations

A pheochromocytoma of the rat adrenal medulla derived (a.k.a. PC12) cell-based assay for dopamine measurement by luminescence detection was customized for the qualitative evaluation of agonists and antagonists of nicotinic acetylcholine receptors (nAChRs). The assay mechanism begins with ligand binding to transmembrane nAChRs, altering ion flow into the cell and inducing dopamine release from the cell. Following release, dopamine is oxidized by monoamine oxidase generating hydrogen peroxide that catalyzes a chemiluminescence reaction involving luminol and horseradish peroxidase, thus producing a detectable response. Results are presented for the action of nAChR agonists (acetylcholine, nicotine, and cytisine), and antagonists (α-conotoxins (α-CTxs) MII, …


Steroidal Alkaloid Variation In Veratrum Californicum As Determined By Modern Methods Of Analytical Analysis, Matthew W. Turner, Meagan Rossi, Vannessa Campfield, John French, Ellie Hunt, Emily Wade, Owen M. Mcdougal Sep 2019

Steroidal Alkaloid Variation In Veratrum Californicum As Determined By Modern Methods Of Analytical Analysis, Matthew W. Turner, Meagan Rossi, Vannessa Campfield, John French, Ellie Hunt, Emily Wade, Owen M. Mcdougal

Chemistry and Biochemistry Faculty Publications and Presentations

Veratrum californicum is a rich source of steroidal alkaloids, many of which have proven to be antagonists of the Hedgehog (Hh) signaling pathway that becomes aberrant in over twenty types of cancer. These alkaloids first became known in the 1950's due to their teratogenic properties, which resulted in newborn and fetal lambs developing cyclopia as a result of pregnant ewes consuming Veratrum californicum. It was discovered that the alkaloids in V. californicum were concentrated in the root and rhizome of the plant with much lower amounts of the most active alkaloid, cyclopamine, present in the aerial plant, especially in …


Radiolysis Of Solid-State Nitrogen Heterocycles Provides Clues To Their Abundance In The Early Solar System, Phillip G. Hammer, Ruiqin Yi, Isao Yoda, H. James Cleaves, Michael P. Callahan Aug 2019

Radiolysis Of Solid-State Nitrogen Heterocycles Provides Clues To Their Abundance In The Early Solar System, Phillip G. Hammer, Ruiqin Yi, Isao Yoda, H. James Cleaves, Michael P. Callahan

Chemistry and Biochemistry Faculty Publications and Presentations

We studied the radiolysis of a wide variety of N-heterocycles, including many of biological importance, and find that the majority are remarkably stable in the solid-state when subjected to large doses of ionizing gamma radiation from a 60Co source. Degradation of N-heterocycles as a function of dose rate and total dose was measured using high performance liquid chromatography with UV detection. Many N-heterocycles show little degradation when γ-irradiated up to a total dose of ~1 MGy, which approximates hundreds of millions of years’ worth of radiation emitted in meteorite parent bodies due to slow radionuclide decay. Extrapolation of …


Nitrogen Heterocycles Form Peptide Nucleic Acid Precursors In Complex Prebiotic Mixtures, Laura E. Rodriguez, Christopher H. House, Karen E. Smith, Melissa R. Roberts, Michael P. Callahan Jun 2019

Nitrogen Heterocycles Form Peptide Nucleic Acid Precursors In Complex Prebiotic Mixtures, Laura E. Rodriguez, Christopher H. House, Karen E. Smith, Melissa R. Roberts, Michael P. Callahan

Chemistry and Biochemistry Faculty Publications and Presentations

The ability to store information is believed to have been crucial for the origin and evolution of life; however, little is known about the genetic polymers relevant to abiogenesis. Nitrogen heterocycles (N-heterocycles) are plausible components of such polymers as they may have been readily available on early Earth and are the means by which the extant genetic macromolecules RNA and DNA store information. Here, we report the reactivity of numerous N-heterocycles in highly complex mixtures, which were generated using a Miller-Urey spark discharge apparatus with either a reducing or neutral atmosphere, to investigate how N-heterocycles are modified under plausible prebiotic …


Organometallic Compounds As Carriers Of Extraterrestrial Cyanide In Primitive Meteorites, Karen E. Smith, Christopher H. House, Ricardo D. Arevalo Jr., Jason P. Dworkin, Michael P. Callahan Jun 2019

Organometallic Compounds As Carriers Of Extraterrestrial Cyanide In Primitive Meteorites, Karen E. Smith, Christopher H. House, Ricardo D. Arevalo Jr., Jason P. Dworkin, Michael P. Callahan

Chemistry and Biochemistry Faculty Publications and Presentations

Extraterrestrial delivery of cyanide may have been crucial for the origin of life on Earth since cyanide is involved in the abiotic synthesis of numerous organic compounds found in extant life; however, little is known about the abundance and species of cyanide present in meteorites. Here, we report cyanide abundance in a set of CM chondrites ranging from 50 ± 1 to 2472 ± 38 nmol·g−1, which relates to the degree of aqueous alteration of the meteorite and indicates that parent body processing influenced cyanide abundance. Analysis of the Lewis Cliff 85311 meteorite shows that its releasable cyanide …


Mutagenesis Of Α-Conotoxins For Enhancing Activity And Selectivity For Nicotinic Acetylcholine Receptors, Matthew W. Turner, Leanna A. Marquart, Paul D. Phillips, Owen M. Mcdougal Feb 2019

Mutagenesis Of Α-Conotoxins For Enhancing Activity And Selectivity For Nicotinic Acetylcholine Receptors, Matthew W. Turner, Leanna A. Marquart, Paul D. Phillips, Owen M. Mcdougal

Chemistry and Biochemistry Faculty Publications and Presentations

Nicotinic acetylcholine receptors (nAChRs) are found throughout the mammalian body and have been studied extensively because of their implication in a myriad of diseases. α-Conotoxins (α-CTxs) are peptide neurotoxins found in the venom of marine snails of genus Conus. -CTxs are potent and selective antagonists for a variety of nAChR isoforms. Over the past 40 years, α-CTxs have proven to be valuable molecular probes capable of differentiating between closely related nAChR subtypes and have contributed greatly to understanding the physiological role of nAChRs in the mammalian nervous system. Here, we review the amino acid composition and structure of several α-CTxs …


Crystal Structure Of A Homoleptic Zinc(Ii) Complex Based On Bis­(3,5-Diiso­Propyl­Pyrazol-1-Yl)Acetate, Josiah G. Elsberg, Nicholas G. Spiropulos, Adam C. Colson, Eric C. Brown Sep 2018

Crystal Structure Of A Homoleptic Zinc(Ii) Complex Based On Bis­(3,5-Diiso­Propyl­Pyrazol-1-Yl)Acetate, Josiah G. Elsberg, Nicholas G. Spiropulos, Adam C. Colson, Eric C. Brown

Chemistry and Biochemistry Faculty Publications and Presentations

Deprotonation of the methyl­ene group in bis­(3,5-diiso­propyl­pyrazol-1-yl)methane with nBuLi and reaction with carbon dioxide yields lithium bis­(3,5-diiso­propyl­pyrazol-1-yl)acetate (1). Treatment of 1 with ZnCl2 results in the com­pound bis­[bis­(3,5-diiso­propyl­pyrazol-1-yl)acetato]­zinc(II), [Zn(C20H31N4O2)2] (2), whose structure has monoclinic (P21/c) symmetry. The ZnII ion resides on an inversion center and is coordinated by two bis­(3,5-diiso­propyl­pyrazol-1-yl)acetate (bdippza) ligands. Each ligand facially coordinates the zinc center via κ3N,N′,O coordination modes to form a distorted octa­hedral complex with four …


Native V. Californicum Alkaloid Combinations Induce Differential Inhibition Of Sonic Hedgehog Signaling, Matthew W. Turner, Roberto Cruz, Jordan Elwell, John French, Jared Mattos, Owen M. Mcdougal Sep 2018

Native V. Californicum Alkaloid Combinations Induce Differential Inhibition Of Sonic Hedgehog Signaling, Matthew W. Turner, Roberto Cruz, Jordan Elwell, John French, Jared Mattos, Owen M. Mcdougal

Chemistry and Biochemistry Faculty Publications and Presentations

Veratrum californicum is a rich source of steroidal alkaloids such as cyclopamine, a known inhibitor of the Hedgehog (Hh) signaling pathway. Here we provide a detailed analysis of the alkaloid composition of V. californicum by plant part through quantitative analysis of cyclopamine, veratramine, muldamine and isorubijervine in the leaf, stem and root/rhizome of the plant. To determine whether additional alkaloids in the extracts contribute to Hh signaling inhibition, the concentrations of these four alkaloids present in extracts were replicated using commercially available standards, followed by comparison of extracts to alkaloid standard mixtures for inhibition of Hh signaling using Shh-Light II …


Solution And Solid-State Characterization Of Zn(Ii) Complexes Containing A New Tridentate N2S Ligand, Valerie Tran, Kate E. Allen, Martin Garcia Chavez, Christopher Aaron, Joseph J. Dumais, John T. York, Eric C. Brown Jun 2018

Solution And Solid-State Characterization Of Zn(Ii) Complexes Containing A New Tridentate N2S Ligand, Valerie Tran, Kate E. Allen, Martin Garcia Chavez, Christopher Aaron, Joseph J. Dumais, John T. York, Eric C. Brown

Chemistry and Biochemistry Faculty Publications and Presentations

A new N2S ligand bis(pyridyl)(2-mercapto-1-methylimidazolyl)methane (2, Py2MeImS) has been synthesized and characterized. Treatment of this ligand with bromide and triflate salts of Zn(II) results in the complexes (Py2MeImS)ZnBr2 (3) and [(Py2MeImS)2Zn](OTf)2 (4), respectively. The solid-state structure of (Py2MeImS)ZnBr2 shows bidentate N,N-coordination of Py2MeImS to the zinc ion, with the sulfur atom of the 2-mercaptoimidazole moiety uncoordinated. Two conformers of 3 rapidly interconvert in solution at room temperature, and variable temperature NMR studies and DFT calculations were used …


Spidr: Small-Molecule Peptide-Influenced Drug Repurposing, Matthew D. King, Thomas Long, Daniel L. Pfalmer, Timothy L. Andersen, Owen M. Mcdougal Apr 2018

Spidr: Small-Molecule Peptide-Influenced Drug Repurposing, Matthew D. King, Thomas Long, Daniel L. Pfalmer, Timothy L. Andersen, Owen M. Mcdougal

Chemistry and Biochemistry Faculty Publications and Presentations

Background: Conventional de novo drug design is costly and time consuming, making it accessible to only the best resourced research organizations. An emergent approach to new drug development is drug repurposing, in which compounds that have already gone through some level of clinical testing are examined for efficacy against diseases divergent than their original application. Repurposing of existing drugs circumvents the time and considerable cost of early stages of drug development, and can be accelerated by using software to screen existing chemical databases to identify suitable drug candidates.

Results: Small-molecule Peptide-Influenced Drug Repurposing (SPIDR) was developed to identify small molecule …