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Articles 1 - 30 of 80
Full-Text Articles in Physical Sciences and Mathematics
In Search Of The X2Bo And X2Bs (X = H, F) Free Radicals: Ab Initio Studies Of Their Spectroscopic Signatures, Dennis J. Clouthier
In Search Of The X2Bo And X2Bs (X = H, F) Free Radicals: Ab Initio Studies Of Their Spectroscopic Signatures, Dennis J. Clouthier
Chemistry Faculty Publications
The F2BO free radical is a known, although little studied, species but similar X2BY (X = H, D, F; Y = O, S) molecules are largely unknown. High level ab initio methods have been used to predict the molecular structures, vibrational frequencies (in cm-1), and relative energies of the ground and first two excited electronic states of these free radicals, as an aid to their eventual spectroscopic identification. The chosen theoretical methods and basis sets were tested on F2BO and found to give good agreement with the known experimental quantities. In particular, …
Enzymes From Fungal And Plant Origin Required For Chemical Diversification Of Insecticidal Loline Alkaloids In Grass-Epichloë Symbiota, Juan Pan, Minakshi Bhardwaj, Padmaja Nagabhyru, Robert B. Grossman, Christopher L. Schardl
Enzymes From Fungal And Plant Origin Required For Chemical Diversification Of Insecticidal Loline Alkaloids In Grass-Epichloë Symbiota, Juan Pan, Minakshi Bhardwaj, Padmaja Nagabhyru, Robert B. Grossman, Christopher L. Schardl
Chemistry Faculty Publications
The lolines are a class of bioprotective alkaloids that are produced by Epichloë species, fungal endophytes of grasses. These alkaloids are saturated 1-aminopyrrolizidines with a C2 to C7 ether bridge, and are structurally differentiated by the various modifications of the 1-amino group: -NH2 (norloline), -NHCH3 (loline), -N(CH3)2 (N-methylloline), -N(CH3)Ac (N-acetylloline), -NHAc (N-acetylnorloline), and -N(CH3)CHO (N-formylloline). Other than the LolP cytochrome P450, which is required for conversion of N-methylloline to N-formylloline, the enzymatic steps for loline diversification have not yet been established. …
Molecular Dynamics Study Of The Opening Mechanism For Dna Polymerase I, Carol A. Parish, Bill R. Miller Iii, Eugene Y. Wu
Molecular Dynamics Study Of The Opening Mechanism For Dna Polymerase I, Carol A. Parish, Bill R. Miller Iii, Eugene Y. Wu
Chemistry Faculty Publications
During DNA replication, DNA polymerases follow an induced fit mechanism in order to rapidly distinguish between correct and incorrect dNTP substrates. The dynamics of this process are crucial to the overall effectiveness of catalysis. Although Xray crystal structures of DNA polymerase I with substrate dNTPs have revealed key structural states along the catalytic pathway, solution fluorescence studies indicate that those key states are populated in the absence of substrate. Herein, we report the first atomistic simulations showing the conformational changes between the closed, open, and ajar conformations of DNA polymerase I in the binary (enzyme:DNA) state to better understand its …
Distinct Conformational Behaviors Of Four Mammalian Dual-Flavin Reductases (Cytochrome P450 Reductase, Methionine Synthase Reductase, Neuronal Nitric Oxide Synthase, Endothelial Nitric Oxide Synthase) Determine Their Unique Catalytic Profiles, Mohammad Mahfuzul Haque, Mekki Bayachou, Jesus Tejero, Claire T. Kenney, Naw M. Pearl, Sang-Choul Im, Lucy Waskell, Dennis J. Stuehr
Distinct Conformational Behaviors Of Four Mammalian Dual-Flavin Reductases (Cytochrome P450 Reductase, Methionine Synthase Reductase, Neuronal Nitric Oxide Synthase, Endothelial Nitric Oxide Synthase) Determine Their Unique Catalytic Profiles, Mohammad Mahfuzul Haque, Mekki Bayachou, Jesus Tejero, Claire T. Kenney, Naw M. Pearl, Sang-Choul Im, Lucy Waskell, Dennis J. Stuehr
Chemistry Faculty Publications
Multidomain enzymes often rely on large conformational motions to function. However, the conformational setpoints, rates of domain motions and relationships between these parameters and catalytic activity are not well understood. To address this, we determined and compared the conformational setpoints and the rates of conformational switching between closed unreactive and open reactive states in four mammalian diflavin NADPH oxidoreductases that catalyze important biological electron transfer reactions: cytochrome P450 reductase, methionine synthase reductase and endothelial and neuronal nitric oxide synthase. We used stopped-flow spectroscopy, single turnover methods and a kinetic model that relates electron flux through each enzyme to its conformational …
Rnase L Contributes To Experimentally Induced Type 1 Diabetes Onset In Mice, Chun Zeng, Xin Yi, Danny Zipris, Hongli Liu, Lin Zhang, Qiaoyun Zheng, Krishnamurthy Malathi, Ge Jin, Aimin Zhou
Rnase L Contributes To Experimentally Induced Type 1 Diabetes Onset In Mice, Chun Zeng, Xin Yi, Danny Zipris, Hongli Liu, Lin Zhang, Qiaoyun Zheng, Krishnamurthy Malathi, Ge Jin, Aimin Zhou
Chemistry Faculty Publications
The cause of type 1 diabetes continues to be a focus of investigation. Studies have revealed that interferon α (IFNα) in pancreatic islets after viral infection or treatment with double-stranded RNA (dsRNA), a mimic of viral infection, is associated with the onset of type 1 diabetes. However, how IFNα contributes to the onset of type 1 diabetes is obscure. In this study, we found that 2-5A-dependent RNase L (RNase L), an IFNα-inducible enzyme that functions in the antiviral and antiproliferative activities of IFN, played an important role in dsRNA-induced onset of type 1 diabetes. Using RNase L-deficient, rat insulin promoter-B7.1 …
The Identification Of Amino Acids By Interpretation Of Titration Curves: An Undergraduate Experiment For Biochemistry, Cassidy M. Dobson, Nathan S. Winter
The Identification Of Amino Acids By Interpretation Of Titration Curves: An Undergraduate Experiment For Biochemistry, Cassidy M. Dobson, Nathan S. Winter
Chemistry Faculty Publications
Undergraduate biochemistry students should have great familiarity with titration curves. These curves allow the prediction of protonation states, charges, and isoelectric points. Here we describe an experiment in which students identify four amino acids based on their titration behavior. Students make solutions of each unknown amino acid and monitor the change in pH upon adding aliquots of a strong base. They identify the amino acids based on the shapes of the curves. They annotate the plots with isoelectric points, pKas, buffering regions and the structures of the amino acids.
Catechol Oxidation By Ozone And Hydroxyl Radicals At The Air-Water Interface, Elizabeth A. Pillar, Robert C. Camm, Marcelo I. Guzman
Catechol Oxidation By Ozone And Hydroxyl Radicals At The Air-Water Interface, Elizabeth A. Pillar, Robert C. Camm, Marcelo I. Guzman
Chemistry Faculty Publications
Anthropogenic emissions of aromatic hydrocarbons promptly react with hydroxyl radicals undergoing oxidation to form phenols and polyphenols (e.g., catechol) typically identified in the complex mixture of humic-like substances (HULIS). Because further processing of polyphenols in secondary organic aerosols (SOA) can continue mediated by a mechanism of ozonolysis at interfaces, a better understanding about how these reactions proceed at the air–water interface is needed. This work shows how catechol, a molecular probe of the oxygenated aromatic hydrocarbons present in SOA, can contribute interfacial reactive species that enhance the production of HULIS under atmospheric conditions. Reactive semiquinone radicals are quickly produced upon …
Comparison Of Crystal Structures Of 4-(Benzo[B]Thiophen-2-Yl)-5-(3,4,5-Trimethoxyphenyl)-2H-1,2,3-Triazole And 4-(Benzo[B]Thiophen-2-Yl)-2-Methyl-5-(3,4,5-Trimethoxyphenyl)-2H-1,2,3-Triazole, Narsimha Reddy Penthala, Nikhil Reddy Madadi, Shobanbabu Bommagani, Sean Parkin, Peter A. Crooks
Comparison Of Crystal Structures Of 4-(Benzo[B]Thiophen-2-Yl)-5-(3,4,5-Trimethoxyphenyl)-2H-1,2,3-Triazole And 4-(Benzo[B]Thiophen-2-Yl)-2-Methyl-5-(3,4,5-Trimethoxyphenyl)-2H-1,2,3-Triazole, Narsimha Reddy Penthala, Nikhil Reddy Madadi, Shobanbabu Bommagani, Sean Parkin, Peter A. Crooks
Chemistry Faculty Publications
The title compound, C19H17N3O3S (I), was prepared by a [3 + 2]cycloaddition azide condensation reaction using sodium azide and l-proline as a Lewis base catalyst. N-Methylation of compound (I) using CH3I gave compound (II), C20H19N3O3S. The benzothiophene ring systems in (I) and (II) are almost planar, with r.m.s deviations from the mean plane = 0.0205 (14) in (I) and 0.016 (2) Å in (II). In (I) and (II), the triazole rings make dihedral angles of 32.68 (5) and 10.43 (8)°, respectively, …
Rnase L Interacts With Filamin A To Regulate Actin Dynamics And Barrier Function For Viral Entry, Krishnamurthy Malathi, Mohammad Adnan Siddiqui, Shubham Dayal, Merna Naji, Heather J, Ezelle, Chun Zeng, Aimin Zhou, Bret A. Hassel
Rnase L Interacts With Filamin A To Regulate Actin Dynamics And Barrier Function For Viral Entry, Krishnamurthy Malathi, Mohammad Adnan Siddiqui, Shubham Dayal, Merna Naji, Heather J, Ezelle, Chun Zeng, Aimin Zhou, Bret A. Hassel
Chemistry Faculty Publications
The actin cytoskeleton and its network of associated proteins constitute a physical barrier that viruses must circumvent to gain entry into cells for productive infection. The mechanisms by which the physical signals of infection are sensed by the host to activate an innate immune response are not well understood. The antiviral endoribonuclease RNase L is ubiquitously expressed in a latent form and activated upon binding 2-5A, a unique oligoadenylate produced during viral infections. We provide evidence that RNase L in its inactive form interacts with the actin-binding protein Filamin A to modulate the actin cytoskeleton and inhibit virus entry. Cells …
Role Of Ca2+ And L-Phe In Regulating Functional Cooperativity Of Disease- Associated ‘‘Toggle’’ Calcium-Sensing Receptor Mutations, Chen Zhang, Nagaraju Mulpuri, Fadil M. Hannan, M. Andrew Nesbit, Rajesh V. Thakker, Donald Hamelberg, Edward M. Brown, Jenny J. Yang
Role Of Ca2+ And L-Phe In Regulating Functional Cooperativity Of Disease- Associated ‘‘Toggle’’ Calcium-Sensing Receptor Mutations, Chen Zhang, Nagaraju Mulpuri, Fadil M. Hannan, M. Andrew Nesbit, Rajesh V. Thakker, Donald Hamelberg, Edward M. Brown, Jenny J. Yang
Chemistry Faculty Publications
The Ca2+-sensing receptor (CaSR) regulates Ca2+ homeostasis in the body by monitoring extracellular levels of Ca2+ ([Ca2+]o) and amino acids. Mutations at the hinge region of the N-terminal Venus flytrap domain (VFTD) produce either receptor inactivation (L173P, P221Q) or activation (L173F, P221L) related to hypercalcemic or hypocalcemic disorders. In this paper, we report that both L173P and P221Q markedly impair the functional positive cooperativity of the CaSR as reflected by [Ca2+]o–induced [Ca2+]i oscillations, inositol-1-phosphate (IP1) accumulation and extracellular signal-regulated kinases (ERK1/2) activity. In contrast, L173F and P221L show enhanced responsiveness of these three functional readouts to [Ca2+]o. Further analysis of …
Interactive Comment On “Iodine Oxide In The Global Marine Boundary Layer” By C. Prados-Roman Et Al., Marcelo I. Guzman
Interactive Comment On “Iodine Oxide In The Global Marine Boundary Layer” By C. Prados-Roman Et Al., Marcelo I. Guzman
Chemistry Faculty Publications
No abstract provided.
Crystal Structure Of 4,5-Bis-(3,4,5-Trimethoxyphenyl)-2H-1,2,3-Triazole Methanol Monosolvate, Nikhil Reddy Madadi, Narsimha Reddy Penthala, Shobanbabu Bommagani, Sean Parkin, Peter A. Crooks
Crystal Structure Of 4,5-Bis-(3,4,5-Trimethoxyphenyl)-2H-1,2,3-Triazole Methanol Monosolvate, Nikhil Reddy Madadi, Narsimha Reddy Penthala, Shobanbabu Bommagani, Sean Parkin, Peter A. Crooks
Chemistry Faculty Publications
The title compound, C20H23N3O6·CH3OH, was synthesized by [3 + 2] cycloaddition of (Z)-2,3-bis(3,4,5-trimethoxyphenyl)acrylonitrile with sodium azide and ammonium chloride in DMF/water. The central nitrogen of the triazole ring is protonated. The dihedral angles between the triazole ring and the 3,4,5-trimethoxyphenyl ring planes are 34.31 (4) and 45.03 (5)°, while that between the 3,4,5-trimethoxyphenyl rings is 51.87 (5)°. In the crystal, the molecules, along with two methanol solvent molecules are linked into an R 4 4(10) centrosymmetric dimer by N—H⋯O and O—H⋯N hydrogen bonds.
Crystal Structure Of (E)-13-{4-[(Z)-2-Cyano-2-(3,4,5-Trimethoxyphenyl)Ethenyl]Phenyl}Parthenolide Methanol Hemisolvate, Narsimha Reddy Penthala, Shobanbabu Bommagani, Venumadhav Janganati, Sean Parkin, Peter A. Crooks
Crystal Structure Of (E)-13-{4-[(Z)-2-Cyano-2-(3,4,5-Trimethoxyphenyl)Ethenyl]Phenyl}Parthenolide Methanol Hemisolvate, Narsimha Reddy Penthala, Shobanbabu Bommagani, Venumadhav Janganati, Sean Parkin, Peter A. Crooks
Chemistry Faculty Publications
The title compound, C33H35NO6 [systematic name: (Z)-3-(4-{(E)-[(E)-1a,5-dimethyl-9-oxo-2,3,7,7a-tetrahydrooxireno[2′,3′:9,10]cyclodeca[1,2-b]furan-8(1aH,6H,9H,10aH,10bH)-ylidene]methyl}phenyl)-2-(3,4,5-trimethoxyphenyl)acrylonitrile methanol hemisolvate], C33H35NO6·0.5CH3OH, was prepared by the reaction of (Z)-3-(4-iodophenyl)-2-(3,4,5-trimethoxyphenyl)acrylonitrile with parthenolide [systematic name: (E)-1a,5-dimethyl-8-methylene-2,3,6,7,7a,8,10a,10b-octahydrooxireno[2′,3′:9,10]cyclodeca[1,2-b]furan-9(1aH)-one] under Heck reaction conditions. The molecule is built up from fused ten-, five- (lactone) and three-membered (epoxide) rings with a {4-[(Z)-2-cyano-2-(3,4,5-trimethoxyphenyl)ethenyl]phenyl}methylidene group as a substituent. The 4-[(Z)-2-cyano-2-(3,4,5-trimethoxyphenyl)ethenyl]phenyl group on the parthenolide exocyclic double bond is …
Evaluation And Monitoring Of Glen Helen Water Quality Fall 2014, Nathaniel Brackett, Brannon Dunn, Robert Magley, Saagar M. Patel, Jennifer Purvis, Sarah R. Steele, Jonathan M. Tumey, Katie Watson, James K. Waweru, Benjamin Wick, Scott N. Atkinson, Audrey E. Mcgowin
Evaluation And Monitoring Of Glen Helen Water Quality Fall 2014, Nathaniel Brackett, Brannon Dunn, Robert Magley, Saagar M. Patel, Jennifer Purvis, Sarah R. Steele, Jonathan M. Tumey, Katie Watson, James K. Waweru, Benjamin Wick, Scott N. Atkinson, Audrey E. Mcgowin
Chemistry Faculty Publications
Poster describing the evaluation and monitoring of water quality in the Glen Helen Nature Preserve, Yellow Springs, Ohio, in the Fall of 2014.
Direct Determination Of Multiple Ligand Interactions With The Extracellular Domain Of The Calcium Sensing Receptor, Chen Zhang, You Zhuo, Heather A. Moniz, Shuo Wang, Kelley W. Moremen, James H. Prestegard, Edward M. Brown, Jenny J. Yang
Direct Determination Of Multiple Ligand Interactions With The Extracellular Domain Of The Calcium Sensing Receptor, Chen Zhang, You Zhuo, Heather A. Moniz, Shuo Wang, Kelley W. Moremen, James H. Prestegard, Edward M. Brown, Jenny J. Yang
Chemistry Faculty Publications
Numerous in vivo functional studies have indicated that the dimeric extracellular domain (ECD) of the CaSR plays a crucial role in regulating Ca2+ homeostasis by sensing Ca2+ and L-Phe. However, direct interaction of Ca2+ and Phe with the receptor’s ECD and the resultant impact on its structure and associated conformational changes have been hampered by the large size of the ECD, its high degree of glycosylation, and the lack of biophysical methods to monitor weak interactions in solution. In the present study, we purified the glycosylated extracellular domain of CaSR (ECD) (residues 20~612), containing either complex or high mannose N-glycan …
A Novel Approach Using Electrospray Ionization Mass Spectrometry To Study Competitive Binding Of Small Molecules With Mixed Dna Sequences, Sarah R. Laughlin, Siming Wang, Arvind Kumar, David Boykin, W. David Wilson
A Novel Approach Using Electrospray Ionization Mass Spectrometry To Study Competitive Binding Of Small Molecules With Mixed Dna Sequences, Sarah R. Laughlin, Siming Wang, Arvind Kumar, David Boykin, W. David Wilson
Chemistry Faculty Publications
Minor groove binding compounds have been shown to induce changes in global DNA conformation, allosterically inhibiting DNA-protein interactions necessary for transcriptional processes. Many minor groove binders are specific for AT-base pairs but have little preference over alternating AT or A-tract sequences. Few compounds, other than polyamides, show selectivity for mixed sequences with AT and GC base pairs. Electrospray ionization mass spectrometry (ESI-MS) can provide insight on the stoichiometry and relative affinities in minor groove recognition of different DNA sequences with a library of minor groove binders. A goal in our current research is to develop new compounds that recognize mixed …
Silyl Trifluoromethanesulfonate-Activated Para-Methoxybenzyl Methyl Ether As An Alkylating Agent For Thiols And Aryl Ketones, C. Wade Downey, Sarah E. Covington, Derek C. Obenschain, Evan Halliday, James T. Rague, Danielle N. Confair
Silyl Trifluoromethanesulfonate-Activated Para-Methoxybenzyl Methyl Ether As An Alkylating Agent For Thiols And Aryl Ketones, C. Wade Downey, Sarah E. Covington, Derek C. Obenschain, Evan Halliday, James T. Rague, Danielle N. Confair
Chemistry Faculty Publications
para-Methoxybenzyl methyl ether acts as an alkylating agent for thiols in the presence of trimethylsilyl trifluoromethanesulfonate and trialkylamine base in good yields (58-96%). Aryl ketones are alkylated under similar conditions, probably through an enol silane intermediate, also in high yields (67-95%). The active alkylating species is likely a p-methoxybenzyl cation.
Scalable Synthesis Of 5,11-Diethynylated Indeno[1,2-B]Fluorene-6,12-Diones And Exploration Of Their Solid State Packing, Bradley D. Rose, Peter J. Santa Maria, Aaron G. Fix, Chris L. Vonnegut, Lev N. Zakharov, Sean R. Parkin, Michael M. Haley
Scalable Synthesis Of 5,11-Diethynylated Indeno[1,2-B]Fluorene-6,12-Diones And Exploration Of Their Solid State Packing, Bradley D. Rose, Peter J. Santa Maria, Aaron G. Fix, Chris L. Vonnegut, Lev N. Zakharov, Sean R. Parkin, Michael M. Haley
Chemistry Faculty Publications
We report a new synthetic route to 5,11-disubstituted indeno[1,2-b]fluorene-6,12-diones that is amenable to larger scale reactions, allowing for the preparation of gram amounts of material. With this new methodology, we explored the effects on crystal packing morphology for the indeno[1,2-b]fluorene-6,12-diones by varying the substituents on the silylethynyl groups.
Crystal Structure Of 1-Methoxy-2,2,2-Tris(Pyrazol-1-Yl)Ethane, Ganna Lyubartseva, Sean Parkin, Morgan D. Coleman, Uma Prasad Mallik
Crystal Structure Of 1-Methoxy-2,2,2-Tris(Pyrazol-1-Yl)Ethane, Ganna Lyubartseva, Sean Parkin, Morgan D. Coleman, Uma Prasad Mallik
Chemistry Faculty Publications
The title compound, C12H14N6O, consists of three pyrazole rings bound via nitrogen to the distal ethane carbon of methoxy ethane. The dihedral angles between the three pyrazole rings are 67.62 (14), 73.74 (14), and 78.92 (12)°. In the crystal, molecules are linked by bifurcated C—H,H⋯N hydrogen bonds, forming double-stranded chains along [001]. The chains are linked via C—H⋯O hydrogen bonds, forming a three-dimensional framework structure. The crystal was refined as a perfect (0.5:0.5) inversion twin.
Prostate Cancer Metastatic To Bone Has Higher Expression Of The Calcium-Sensing Receptor (Casr) Than Primary Prostate Cancer, Jie Feng, Xiaojun Xu, Bo Li, Edward Brown, Alton B. Farris, Shi-Yong Sun, Jenny J. Yang
Prostate Cancer Metastatic To Bone Has Higher Expression Of The Calcium-Sensing Receptor (Casr) Than Primary Prostate Cancer, Jie Feng, Xiaojun Xu, Bo Li, Edward Brown, Alton B. Farris, Shi-Yong Sun, Jenny J. Yang
Chemistry Faculty Publications
The calcium-sensing receptor (CaSR) is the principal regulator of the secretion of parathyroid hormone and plays key roles in extracellular calcium (Ca2+o) homeostasis. It is also thought to participate in the development of cancer, especially bony metastases of breast and prostate cancer. However, the expression of CaSR has not been systematically analyzed in prostate cancer from patients with or without bony metastases. By comparing human prostate cancer tissue sections in microarrays, we found that the CaSR was expressed in both normal prostate and primary prostate cancer as assessed by immunohistochemistry (IHC). We used two methods to analyze the expression level …
Low-Temperature Phase Transitions In A Soluble Oligoacene And Their Effect On Device Performance And Stability, J. W. Ward, K. P. Goetz, A. Obaid, Marcia M. Payne, P. J. Diemer, C. S. Day, John E. Anthony, O. D. Jurchescu
Low-Temperature Phase Transitions In A Soluble Oligoacene And Their Effect On Device Performance And Stability, J. W. Ward, K. P. Goetz, A. Obaid, Marcia M. Payne, P. J. Diemer, C. S. Day, John E. Anthony, O. D. Jurchescu
Chemistry Faculty Publications
The use of organic semiconductors in high-performance organic field-effect transistors requires a thorough understanding of the effects that processing conditions, thermal, and bias-stress history have on device operation. Here, we evaluate the temperature dependence of the electrical properties of transistors fabricated with 2,8-difluoro-5,11-bis(triethylsilylethynyl)anthradithiophene, a material that has attracted much attention recently due to its exceptional electrical properties. We have discovered a phase transition at T = 205 K and discuss its implications on device performance and stability. We examined the impact of this low-temperature phase transition on the thermodynamic, electrical, and structural properties of both single crystals and thin films …
Silyl Triflate-Accelerated Additions Of Catalytically Generated Zinc Acetylides To N-Phenyl Nitrones, C. Wade Downey, Erin N. Maxwell, Danielle N. Confair
Silyl Triflate-Accelerated Additions Of Catalytically Generated Zinc Acetylides To N-Phenyl Nitrones, C. Wade Downey, Erin N. Maxwell, Danielle N. Confair
Chemistry Faculty Publications
Terminal alkynes readily form zinc acetylides in the presence of iPr2NEt and 20 mol% ZnBr2, then attack N-phenyl nitrones activated by trimethylsilyl trifluoromethanesulfonate. Deprotection with aqueous acid yields the N-hydroxyl propargylamine. Yields are generally high for nitrones derived from aromatic aldehydes. Control experiments suggest that the silyl triflate has a significant accelerating effect upon the reaction.
Persistent Hepatic Structural Alterations Following Nanoceria Vascular Infusion In The Rat, Michael T. Tseng, Qiang Fu, Khoua Lor, G. Rafael Fernandez-Botran, Zhong-Bin Deng, Uschi M. Graham, D. Allan Butterfield, Eric A. Grulke, Robert A. Yokel
Persistent Hepatic Structural Alterations Following Nanoceria Vascular Infusion In The Rat, Michael T. Tseng, Qiang Fu, Khoua Lor, G. Rafael Fernandez-Botran, Zhong-Bin Deng, Uschi M. Graham, D. Allan Butterfield, Eric A. Grulke, Robert A. Yokel
Chemistry Faculty Publications
Understanding the long-term effects and possible toxicity of nanoceria, a widely utilized commercial metal oxide, is of particular importance as it is poised for development as a therapeutic agent based on its autocatalytic redox behavior. We show here evidence of acute and subacute adverse hepatic responses, after a single infusion of an aqueous dispersion of 85 mg/kg, 30 nm nanoceria into Sprague Dawley rats. Light and electron microscopic evidence of avid uptake of nanoceria by Kupffer cells was detected as early as 1 hr after infusion. Biopersistent nanoceria stimulated cluster of differentiation 3+ lymphocyte proliferation that intermingled with nanoceria-containing …
Iron(Ii)-Catalyzed Intermolecular Amino-Oxygenation Of Olefins Through The N−O Bond Cleavage Of Functionalized Hydroxylamines, Deng-Fu Lu, Cheng-Liang Zhu, Zhen-Xin Jia, Hao Xu
Iron(Ii)-Catalyzed Intermolecular Amino-Oxygenation Of Olefins Through The N−O Bond Cleavage Of Functionalized Hydroxylamines, Deng-Fu Lu, Cheng-Liang Zhu, Zhen-Xin Jia, Hao Xu
Chemistry Faculty Publications
An iron-catalyzed diastereoselective intermolecular olefin amino-oxygenation reaction is reported, which proceeds via an iron-nitrenoid generated by the N− O bond cleavage of a functionalized hydroxylamine. In this reaction, a bench-stable hydroxylamine derivative is used as the amination reagent and oxidant. This method tolerates a range of synthetically valuable substrates that have been all incompatible with existing amino-oxygenation methods. It can also provide amino alcohol derivatives with regio- and stereochemical arrays complementary to known amino-oxygenation methods.
Heat Release Of Polyurethanes Containing Potential Flame Retardants Based On Boron And Phosphorus Chemistries, Vladimir Benin, Bastien Gardelle, Alexander Morgan
Heat Release Of Polyurethanes Containing Potential Flame Retardants Based On Boron And Phosphorus Chemistries, Vladimir Benin, Bastien Gardelle, Alexander Morgan
Chemistry Faculty Publications
Using a polyurethane of methylene diphenyl isocyanate and 1,3-propane diol, several new non-halogenated aromatic boron and phosphorus flame retardants were evaluated for heat release reduction potential using the pyrolysis combustion flow calorimeter (PCFC). The polyurethanes were prepared in the presence of the potential flame retardants via solvent mixing and copolymerization methods, and were then analyzed via spectroscopic methods to determine if the flame retardant was still present in the final product. PCFC testing on the resulting products showed that the flame retardant molecule can have different effects on heat release depending upon how it is mixed into the polyurethane. Some …
Cryoprotective Effect Of L-Carnitine On Motility, Vitality And Dna Oxidation Of Human Spermatozoa, S. Banihani, A. Agarwal, R. Sharma, Mekki Bayachou
Cryoprotective Effect Of L-Carnitine On Motility, Vitality And Dna Oxidation Of Human Spermatozoa, S. Banihani, A. Agarwal, R. Sharma, Mekki Bayachou
Chemistry Faculty Publications
Successful cryopreservation for human spermatozoa markedly influences the reproductive outcomes of assisted reproductive technologies. But in spite of its usefulness, cryopreservation significantly decreases sperm quality. l-carnitine has been found to improve the quality of spermatozoa in selected cases with male infertility. Here, we examined the efficacy of l-carnitine in improving sperm motility and vitality and reducing sperm DNA oxidation during cryopreservation. Semen samples from infertile patients (n = 22) were collected and analysed. Cryopreservation medium supplemented with l-carnitine was mixed with the semen at a ratio of 1 : 1 (v/v). The final l-carnitine concentration in each cryovial was 0.5 …
Enhanced Charge Photogeneration Promoted By Crystallinity In Small-Molecule Donor-Acceptor Bulk Heterojunctions, Keshab Paudel, Brian Johnson, Mattson Thieme, Michael M. Haley, Marcia M. Payne, John E. Anthony, Oksana Ostroverkhova
Enhanced Charge Photogeneration Promoted By Crystallinity In Small-Molecule Donor-Acceptor Bulk Heterojunctions, Keshab Paudel, Brian Johnson, Mattson Thieme, Michael M. Haley, Marcia M. Payne, John E. Anthony, Oksana Ostroverkhova
Chemistry Faculty Publications
We examined sub-nanosecond time-scale charge carrier dynamics in crystalline films of a functionalized anthradithiophene (ADT) donor (D) with three different acceptor (A) molecules. A four-fold enhancement in ultrafast charge carrier separation efficiency was observed in D/A blends with a fullerene acceptor added at 7–10 wt. % concentrations, whereas a gradual decrease in peak photocurrent amplitude with acceptor concentration was observed with functionalized pentacene and indenofluorene acceptors. The results were directly correlated with the ADT-tri(ethylsilyl)ethynyl-F donor crystallinity. In the best-performing blends, the presence of crystalline acceptor domains was also established.
Determination Of Corrosion Inhibitor Lubricity Improver In Jet Fuel By Liquid Chromatography-Electrospray Ionization Mass Spectrometry, David W. Johnson, Milissa Flake, Ryan Adams
Determination Of Corrosion Inhibitor Lubricity Improver In Jet Fuel By Liquid Chromatography-Electrospray Ionization Mass Spectrometry, David W. Johnson, Milissa Flake, Ryan Adams
Chemistry Faculty Publications
Military jet fuel (JP-8) is very similar to commercial jet fuel (Jet A) except for the presence of three additives, fuel system icing inhibitor, corrosion inhibitor–lubricity improver (CI-LI), and antistatic additive, which are added to improve characteristics of JP-8. Of particular interest is the CI-LI additive; the most common active ingredient is a dimer of linoleic acid. This article focuses on quantification of the active ingredient in the CI-LI additive by liquid chromatography–mass spectrometry (LC–MS). This method will allow the determination of CI-LI content in military jet fuel samples.
Metabolomics Of Apcmin/+ Mice Genetically Susceptible To Intestinal Cancer, Jean Eudes J. Dazard, Yana Sandlers, Stephanie K. Doerner, Nathan A. Berger, Henri Brunengraber
Metabolomics Of Apcmin/+ Mice Genetically Susceptible To Intestinal Cancer, Jean Eudes J. Dazard, Yana Sandlers, Stephanie K. Doerner, Nathan A. Berger, Henri Brunengraber
Chemistry Faculty Publications
Background: To determine how diets high in saturated fat could increase polyp formation in the mouse model of intestinal neoplasia, ApcMin/+, we conducted large-scale metabolome analysis and association study of colon and small intestine polyp formation from plasma and liver samples of ApcMin/+ vs. wild-type littermates, kept on low vs. high-fat diet. Label-free mass spectrometry was used to quantify untargeted plasma and acyl-CoA liver compounds, respectively. Differences in contrasts of interest were analyzed statistically by unsupervised and supervised modeling approaches, namely Principal Component Analysis and Linear Model of analysis of variance. Correlation between plasma metabolite concentrations and polyp numbers was …
A New Liquid Chromatography/Tandem Mass Spectrometry Method For Quantification Of Gangliosides In Human Plasma, Qianyang Huang, Xiang Zhou, Danting Liu, Baozhong Xin, Karen Cechner, Heng Wang, Aimin Zhou
A New Liquid Chromatography/Tandem Mass Spectrometry Method For Quantification Of Gangliosides In Human Plasma, Qianyang Huang, Xiang Zhou, Danting Liu, Baozhong Xin, Karen Cechner, Heng Wang, Aimin Zhou
Chemistry Faculty Publications
Gangliosides are a family of glycosphingolipids characterized by mono- or polysialic acid-containing oligosaccharides linked through 1,3- and 1,4-β glycosidic bonds with subtle differences in structure that are abundantly present in the central nervous systems of many living organisms. Their cellular surface expression and physiological malfunction are believed to be pathologically implicated in considerable neurological disorders, including Alzheimer and Parkinson diseases. Recently, studies have tentatively elucidated that mental retardation or physical stagnation deteriorates as the physiological profile of gangliosides becomes progressively and distinctively abnormal during the development of these typical neurodegenerative syndromes. In this work, a reverse-phase liquid chromatography/tandem mass spectrometry …