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Articles 1 - 30 of 111
Full-Text Articles in Organic Chemistry
Friedel–Crafts Addition Of 3-Alkylated Indoles To Aldehydes: 2-Hydroxyalkylation Promoted By Trimethylsilyl Trifluoromethanesulfonate, Eric Zhou, Helen Xia, C. Wade Downey
Friedel–Crafts Addition Of 3-Alkylated Indoles To Aldehydes: 2-Hydroxyalkylation Promoted By Trimethylsilyl Trifluoromethanesulfonate, Eric Zhou, Helen Xia, C. Wade Downey
Chemistry Faculty Publications
In the presence of trimethylsilyl trifluoromethanesulfonate (TMSOTf) and 2,6-lutidine, 3-alkylated indoles undergo Friedel–Crafts silyloxyalkylation when treated with nonenolizable aldehydes. The reaction is general across a wide range of aromatic aldehydes and tolerates a variety of N-alkylated indoles. Deprotection of the silylated product occurs under standard conditions, and in certain cases the initial TMS-protected product can be isolated in high yield.
Herbularyo (Folk Healer): An Herbal Medicine Card Game, Maryjane T. Magsino, Inah Marie Q. Rivera, Armando M. Guidote, Genejane M. Adarlo
Herbularyo (Folk Healer): An Herbal Medicine Card Game, Maryjane T. Magsino, Inah Marie Q. Rivera, Armando M. Guidote, Genejane M. Adarlo
Chemistry Faculty Publications
Herbularyo, a card game teaching about herbal plants (HPs), was created and evaluated as a viable educational card game based on Tuomisto and Aksela’s criteria. A quasi-experiment was performed on 81 Grade 8 students from a private high school and 50 Grade 11 from a public high school. Independent t-test revealed that the control group (CG) and experimental group (EG) (p=0.386), and EG1 (played ≤5) and EG2 (played >5) (p=0.681) are not comparable with each other. Paired t-test showed EG performed better (p=0.001) than CG (p=0.901) whereas ANCOVA showed that playing Herbularyo improved students’ information retention (p=0.006). EG1 and EG2 …
Substituent Effects And Mechanistic Insights On The Catalytic Activities Of (Tetraarylcyclopentadienone)Iron Carbonyl Compounds In Transfer Hydrogenations And Dehydrogenations, Bryn K. Werley, Xintong Hou, Evan P. Bertonazzi, Anthony Chianese, Timothy W. Funk
Substituent Effects And Mechanistic Insights On The Catalytic Activities Of (Tetraarylcyclopentadienone)Iron Carbonyl Compounds In Transfer Hydrogenations And Dehydrogenations, Bryn K. Werley, Xintong Hou, Evan P. Bertonazzi, Anthony Chianese, Timothy W. Funk
Chemistry Faculty Publications
(Cyclopentadienone)iron carbonyl compounds are catalytically active in carbonyl/imine reductions, alcohol oxidations, and borrowing hydrogen reactions, but the effect of cyclopentadienone electronics on their activity is not well established. A series of (tetraarylcyclopentadienone)iron tricarbonyl compounds with varied electron densities on the cyclopentadienone were prepared, and their activities in transfer hydrogenations and dehydrogenations were explored. Additionally, mechanistic studies, including kinetic isotope effect experiments and modifications to substrate electronics, were undertaken to gain insights into catalyst resting states and turnover-limiting steps of these reactions. As the cyclopentadienone electron density increased, both the transfer hydrogenation and dehydrogenation rates increased. A catalytically relevant, trimethylamine-ligated iron …
One-Pot Enol Silane Formation-Allylation Of Ketones Promoted By Trimethylsilyl Trifluoromethanesulfonate, Elizabeth D. Heafner, Xuechun Lin, Alexa Connors, Hanyu Zhong, R. J. Coyle, Yiqi Liu, C. Wade Downey
One-Pot Enol Silane Formation-Allylation Of Ketones Promoted By Trimethylsilyl Trifluoromethanesulfonate, Elizabeth D. Heafner, Xuechun Lin, Alexa Connors, Hanyu Zhong, R. J. Coyle, Yiqi Liu, C. Wade Downey
Chemistry Faculty Publications
Ketones and related substrate classes undergo enol silane formation in the presence of trimethylsilyl trifluoromethanesulfonate (TMSOTf) and triethylamine, reaction conditions that also promote the in situ ionization of allyl propionates. When these two processes are performed in one pot, allylation of the ketone is observed in high yields. Aldehydes, esters, and thioesters also serve as enol silane precursors under these conditions. When unsymmetrical allyl cations are employed, regioselectivity depends upon the electronic and steric properties of the substituents.
Synthesis Of Β,Β-Disubstituted Styrenes Via Trimethylsilyl Trifluoromethanesulfonate-Promoted Aldehyde-Aldehyde Aldol Addition-Deformylative Elimination., Grant J. Dixon, Michael R. Rodriguez, Tyler G. Chong, Kevin Y. Kim, C. Wade Downey
Synthesis Of Β,Β-Disubstituted Styrenes Via Trimethylsilyl Trifluoromethanesulfonate-Promoted Aldehyde-Aldehyde Aldol Addition-Deformylative Elimination., Grant J. Dixon, Michael R. Rodriguez, Tyler G. Chong, Kevin Y. Kim, C. Wade Downey
Chemistry Faculty Publications
In the presence of trimethylsilyl trifluoromethanesulfonate (TMSOTf) and 2,6-lutidine, α,α-disubstituted aldehydes condense with electron-rich aromatic aldehydes to yield β, β- disubstituted styrenes. More electron-rich aromatic aldehydes react more rapidly and in higher yield. Preliminary results suggest that the reaction may proceed via the ionization and formal deformylation of an aldol intermediate.
The Application Of 13c Nmr And Untargeted Multivariate Analysis For Classifying Virgin Coconut Oil, Lolita G. Lagurin, Mark Joseph Garrovillas, Fabian M. Dayrit
The Application Of 13c Nmr And Untargeted Multivariate Analysis For Classifying Virgin Coconut Oil, Lolita G. Lagurin, Mark Joseph Garrovillas, Fabian M. Dayrit
Chemistry Faculty Publications
Virgin coconut oil (VCO) is produced from fresh mature coconut meat without the use of chemicals or high heat. VCO can be made using three processes: fermentation, centrifuge, and expeller. To determine quality, it is important to be able to differentiate control VCO (fresh) from old VCO, refined bleached and deodorized coconut oil (RBDCO), and VCO which has been adulterated with RBDCO. Differentiating these types of samples has remained a challenge because of their chemical similarity. This study investigated the ability of 13C NMR and multivariate analysis to differentiate these different coconut oil samples. The methodology used the standard 13C …
One-Pot Synthesis Of 2-Methylfurans From 3- (Trimethylsilyl)Propargyl Acetates Promoted By Trimethylsilyl Trifluoromethanesulfonate, Danielle E. Sklar, Alex V. Helbling, Yiqi Liu, C. Wade Downey
One-Pot Synthesis Of 2-Methylfurans From 3- (Trimethylsilyl)Propargyl Acetates Promoted By Trimethylsilyl Trifluoromethanesulfonate, Danielle E. Sklar, Alex V. Helbling, Yiqi Liu, C. Wade Downey
Chemistry Faculty Publications
In the presence of trimethylsilyl trifluoromethanesulfonate (TMSOTf) and triethylamine, 3-(trimethylsilyl)propargyl carboxylates undergo a one-pot alkylation-cyclization- desilylation reaction with ketones to produce 2-methylfurans. Alkylation at 0 °C in methylene chloride, followed by acid-catalyzed cyclization at room temperature, provides the furans in 52-86% yield. Cyclization and desilylation appear to be promoted by triflic acid generated in situ from the exposure of the reaction mixture to water upon completion of the initial substitution reaction.
Friedel–Crafts Addition Of Indoles To Nitrones Promoted By Trimethylsilyl Trifluoromethanesulfonate, Zachary Z. Oracheff, Helen L. Xia, Christopher D. Poff, Scott E. Isaacson, C. Wade Downey
Friedel–Crafts Addition Of Indoles To Nitrones Promoted By Trimethylsilyl Trifluoromethanesulfonate, Zachary Z. Oracheff, Helen L. Xia, Christopher D. Poff, Scott E. Isaacson, C. Wade Downey
Chemistry Faculty Publications
N-alkylindoles undergo Friedel–Crafts addition to aryl and secondary alkyl nitrones in the presence of trimethylsilyl trifluoromethanesulfonate and a trialkylamine to produce 3-(1- (silyloxyamino)alkyl)indoles. Spontaneous conversion to the bisindolyl(aryl)methanes, which is thermodynamically favored for nitrones derived from aromatic aldehydes, is suppressed under the reaction conditions. The silyloxyamino group can be deprotected with tetrabutylammonium fluoride to yield the hydroxylamine.
Profile Of Volatile Organic Compounds (Vocs) From Cold-Processed And Heat-Treated Virgin Coconut Oil (Vco) Samples, Ian Ken D. Dimzon, Grace B. Tantengco, Noel A. Oquendo, Fabian M. Dayrit
Profile Of Volatile Organic Compounds (Vocs) From Cold-Processed And Heat-Treated Virgin Coconut Oil (Vco) Samples, Ian Ken D. Dimzon, Grace B. Tantengco, Noel A. Oquendo, Fabian M. Dayrit
Chemistry Faculty Publications
Virgin coconut oil (VCO) can be prepared with or without heat. Fermentation and centrifuge processes can be done without the use of heat (cold process), while expelling involves heat due to friction. Volatile organic compounds (VOCs) from VCO samples prepared using these three methods were collected using solid phase microextraction (SPME) and analyzed using gas chromatography–mass spectrometry (GC-MS). Twenty-seven VCO samples from nine VCO producers were analyzed. The VOCs from refined, bleached, and deodorized coconut oil (RBDCO) were also obtained for comparison. Fourteen compounds were found to be common in more than 80% of the VCO samples analyzed. These included: …
A New Lc-Ms/Ms Technique For Separation Of Gangliosides Using A Phenyl-Hexyl Column: Systematic Separation According To Sialic Acid Class And Ceramide Subclass, Ashta Lakshmi Prasad Gobburi, Eric Wekesa Kipruto, Denise M. Inman, David J. Anderson
A New Lc-Ms/Ms Technique For Separation Of Gangliosides Using A Phenyl-Hexyl Column: Systematic Separation According To Sialic Acid Class And Ceramide Subclass, Ashta Lakshmi Prasad Gobburi, Eric Wekesa Kipruto, Denise M. Inman, David J. Anderson
Chemistry Faculty Publications
A LC-MS/MS technique separated the bovine and mouse brain gangliosides monosialotetrahexosylgangliosides (GM1), disialotetrahexosylgangliosides (GD1a), trisialotetrahexosylgangliosides (GT1b) and tetrasialotetrahexosylgangliosides (GQ1b) using a phenyl-hexyl HPLC column and employing a linear methanol gradient in water, which is 0.028% in ammonium hydroxide. The gangliosides were separated according to sialic acid class, and within a particular class, gangliosides having different ceramide carbon chain lengths were also separated. All gangliosides of a particular sialic acid class eluted in characteristic retention time windows in the order of GQ1b, (earliest), GT1b, GD1a, and GM1 (latest). Within each specific retention time window for a particular ganglioside class, gangliosides were …
Ruggedized Color Measurement For Beer, Wort, And Malt, Roger Barth, Randall H. Reiger, Yuki Kim
Ruggedized Color Measurement For Beer, Wort, And Malt, Roger Barth, Randall H. Reiger, Yuki Kim
Chemistry Faculty Publications
The standard instrument for measuring malt, wort, and beer color is the spectrophotometer. Spectrophotometers are not rugged; they have critically aligned collimators, monochromators, lenses, slits, and mirrors that make them difficult to use and maintain in a production environment. Our research shows that wort and beer color can be measured accurately with rugged equipment based on light emitting diodes (LEDs) with results in agreement with those of a spectrophotometer. Two or more colored diodes were used. LED-based apparatus does not require critical alignment, is not highly sensitive to environmental conditions such as temperature, moisture, dust, and vibration, and can be …
Teaching College Chemistry In The Time Of Covid-19 Pandemic: A Personal Account Of Teaching In The Old Normal Vs. The New Normal, Armando M. Guidote Jr
Teaching College Chemistry In The Time Of Covid-19 Pandemic: A Personal Account Of Teaching In The Old Normal Vs. The New Normal, Armando M. Guidote Jr
Chemistry Faculty Publications
The SARS CoV-2 (Severe Acute Respiratory Syndrome CoronaVirus 2), cause of COVID-19 (CoronaVirus Disease 2019) has afflicted close to 10 million people all over the world resulting to almost half a million deaths. This disease is severely contagious and necessitates social or physical distancing between persons. As such, traditional face-to-face learning is not advised and teachers need to shift to online teaching. There are challenges to online teaching and learning for students, teachers, and the higher education institute, e.g. hardware, bandwidth, and software issues. These will be difficult but these can be overcome eventually. This work is a personal account …
Improving The Value Of The Coconut With Biotechnology, Fabian M. Dayrit, Quang Nguyen
Improving The Value Of The Coconut With Biotechnology, Fabian M. Dayrit, Quang Nguyen
Chemistry Faculty Publications
The fruit of the coconut tree is perhaps the most useful plant resource in the tropics. All parts of the coconut fruit have traditional uses that have been developed commercially in recent times (Foale 2003, Dayrit and Dayrit 2013). Due to its widespread household use, trade and industry statistics on coconut products reflect only part of the actual importance of the coconut. Today, coconut-based products have gone beyond the tropics and are consumed in many temperate countries and global regions such as Australia, China, Europe, North America, and the Middle East (Costello 2018). Coconut milk is the basic ingredient of …
Feasibility Of Cyclodextrin-Potassium Ion Assemblies Synthesis And Its Application In Loading Bio-Active Molecules, Yomkippur Perez, Gilbert U. Yu
Feasibility Of Cyclodextrin-Potassium Ion Assemblies Synthesis And Its Application In Loading Bio-Active Molecules, Yomkippur Perez, Gilbert U. Yu
Chemistry Faculty Publications
In the study, colorless cubic crystals of “green” cyclodextrin (CD)-based assemblies were synthesized and their potential to load bio-active molecules such as drugs and, separately, enzymes were investigated. Busulfan (Bu), an anti-cancer drug widely used to treat chronic myelogenous leukemia (CML), was used as a test drug while trypsin and lipase were used as model enzymes. These porous CD-K+ ion assemblies were prepared by dissolving alkali metal salts and γ-CD in water followed by vapor diffusion in varying solvents for several days. Crystals were activated via dichloromethane dispersion and in vacuo drying. Slow vapor diffusion with ethanol was found to …
One-Pot Silyl Ketene Imine Formation-Nucleophilic Addition Reactions Of Acetonitrile With Acetals And Nitrones, C. Wade Downey, Grace Ann L. Robertson, Jhonmattew Santa, Kari R. Flicker, William M. Stith
One-Pot Silyl Ketene Imine Formation-Nucleophilic Addition Reactions Of Acetonitrile With Acetals And Nitrones, C. Wade Downey, Grace Ann L. Robertson, Jhonmattew Santa, Kari R. Flicker, William M. Stith
Chemistry Faculty Publications
Trimethylsilyl trifluoromethanesulfonate (TMSOTf) and a trialkylamine base promote the conversion of acetonitrile to its silyl ketene imine in situ when acetonitrile is employed as solvent. Residual TMSOTf acts as a Lewis acid catalyst to activate acetals and nitrones in the reaction mixture, yielding β-methoxynitriles and β-(silyloxy)aminonitriles, respectively. Some reaction products undergo elimination under the reaction conditions to provide the α,β-unsaturated nitrile directly.
(Cyclopentadienone)Iron-Catalyzed Transfer Dehydrogenation Of Symmetrical And Unsymmetrical Diols To Lactones, Yidan Tang, Rowan I.L. Meador, Casina T. Malinchak, Emily E. Harrison, Kimberly A. Mccaskey, Melanie C. Hempel, Timothy W. Funk
(Cyclopentadienone)Iron-Catalyzed Transfer Dehydrogenation Of Symmetrical And Unsymmetrical Diols To Lactones, Yidan Tang, Rowan I.L. Meador, Casina T. Malinchak, Emily E. Harrison, Kimberly A. Mccaskey, Melanie C. Hempel, Timothy W. Funk
Chemistry Faculty Publications
Air-stable iron carbonyl compounds bearing cyclopentadienone ligands with varying substitution were explored as catalysts in dehydrogenative diol lactonization reactions using acetone as both the solvent and hydrogen acceptor. Two catalysts with trimethylsilyl groups in the 2- and 5-positions, [2,5-(SiMe3)2-3,4-(CH2)4(η4-C4C═O)]Fe(CO)3 (1) and [2,5-(SiMe3)2-3,4-(CH2)3(η4-C4C═O)]Fe(CO)3 (2), were found to be the most active, with 2 being the most selective in the lactonization of diols containing both primary and secondary alcohols. Lactones containing five-, six-, and seven-membered rings were successfully synthesized, and no over-oxidations to carboxylic acids were detected. The lactonization of unsymmetrical diols containing two …
Production Of Singlet Oxygen (1O2) During The Photochemistry Of Aqueous Pyruvic Acid: The Effects Of Ph And Photon Flux Under Steady-State O2(Aq) Concentration, Alexis J. Eugene, Marcelo I. Guzman
Production Of Singlet Oxygen (1O2) During The Photochemistry Of Aqueous Pyruvic Acid: The Effects Of Ph And Photon Flux Under Steady-State O2(Aq) Concentration, Alexis J. Eugene, Marcelo I. Guzman
Chemistry Faculty Publications
The photochemistry of pyruvic acid (PA) in aqueous atmospheric particles contributes to the production of secondary organic aerosols. This work investigates the fate of ketyl and acetyl radicals produced during the photolysis (λ ≥ 305 nm) of 5-100 mM PA under steady state [O2(aq)] = 260 μM (1.0 ≤ pH ≤ 4.5) for photon fluxes between 1 and 10 suns. The radicals diffuse quickly into the water/air interface of microbubbles and react with dissolved O2 to produce singlet oxygen (1O2*). Furfuryl alcohol is used to trap and bracket the steady-state production of …
Crystal Structure Of Zymonic Acid And A Redetermination Of Its Precursor, Pyruvic Acid, Dominik Heger, Alexis J. Eugene, Sean R. Parkin, Marcelo I. Guzman
Crystal Structure Of Zymonic Acid And A Redetermination Of Its Precursor, Pyruvic Acid, Dominik Heger, Alexis J. Eugene, Sean R. Parkin, Marcelo I. Guzman
Chemistry Faculty Publications
The structure of zymonic acid (systematic name: 4-hydroxy-2-methyl-5-oxo-2,5-dihydrofuran-2-carboxylic acid), C6H6O5, which had previously eluded crystallographic determination, is presented here for the first time. It forms by intramolecular condensation of parapyruvic acid, which is the product of aldol condensation of pyruvic acid. A redetermination of the crystal structure of pyruvic acid (systematic name: 2-oxopropanoic acid), C3H4O3, at low temperature (90 K) and with increased precision, is also presented [for the previous structure, see: Harata et al. (1977). Acta Cryst. B33, 210–212]. In zymonic acid, the hydroxylactone ring …
The Effects Of Reactant Concentration And Air Flow Rate In The Consumption Of Dissolved O2 During The Photochemistry Of Aqueous Pyruvic Acid, Alexis J. Eugene, Marcelo I. Guzman
The Effects Of Reactant Concentration And Air Flow Rate In The Consumption Of Dissolved O2 During The Photochemistry Of Aqueous Pyruvic Acid, Alexis J. Eugene, Marcelo I. Guzman
Chemistry Faculty Publications
The sunlight photochemistry of the organic chromophore pyruvic acid (PA) in water generates ketyl and acetyl radicals that contribute to the production and processing of atmospheric aerosols. The photochemical mechanism is highly sensitive to dissolved oxygen content, [O2(aq)], among other environmental conditions. Thus, herein we investigate the photolysis (λ ≥ 305 nm) of 10–200 mM PA at pH 1.0 in water covering the relevant range 0 ≤ [O2(aq)] ≤ 1.3 mM. The rapid consumption of dissolved oxygen by the intermediate photolytic radicals is monitored in real time with a dissolved oxygen electrode. …
Metal-Assisted Hydrolysis Reactions Involving Lipids: A Review, Dominique E. Williams, Kathryn B. Grant
Metal-Assisted Hydrolysis Reactions Involving Lipids: A Review, Dominique E. Williams, Kathryn B. Grant
Chemistry Faculty Publications
This report covers major advances in the use of metal ions and complexes to hydrolyze ester and phosphate ester lipid bonds. These metal-based Lewis acids have been investigated as catalysts to isolate fatty acids from biological sources, as probes to study phospholipid bilayer properties, as tools to examine signal transduction pathways, and as lead compounds toward the discovery of therapeutic agents. Metal ions that accelerate phosphate ester hydrolysis under mild conditions of temperature and pH may have the potential to mimic phospholipase activity in biochemical applications.
Carbohydrate Polymers As Controlled Release Devices For Pesticides, Soma Chakraborty, Maria Cleofe Neri-Badang
Carbohydrate Polymers As Controlled Release Devices For Pesticides, Soma Chakraborty, Maria Cleofe Neri-Badang
Chemistry Faculty Publications
Controlled release technology addresses problems associated with excessive use of toxic agricultural chemicals. This paper reviews the studies on the use of carbohydrate polymers as controlled release matrices for pesticides. Alginates, starch and its derivatives, chitosan, carboxymethylcellulose and ethylcellulose are some of the natural polymers discussed in this review. The advantages and disadvantages of these polymeric systems as well as the factors that affect pesticide release are presented. A discussion on the polymers’ encapsulation efficiency and release profile is also included, which will aid future researchers in identifying the suitable formulation for controlled release of pesticides. Combination of two polymers, …
One-Pot Enol Silane Formation-Mukaiyama Aldol Reactions: Crossed Aldehyde-Aldehyde Coupling, Thioester Substrates, And Reactions In Ester Solvents, C. Wade Downey, Grant J. Dixon, Jared A. Ingersoll, Claire A. Fuller, Kenneth W. Maccormac, Anna Takashima, Rohina Sediqui
One-Pot Enol Silane Formation-Mukaiyama Aldol Reactions: Crossed Aldehyde-Aldehyde Coupling, Thioester Substrates, And Reactions In Ester Solvents, C. Wade Downey, Grant J. Dixon, Jared A. Ingersoll, Claire A. Fuller, Kenneth W. Maccormac, Anna Takashima, Rohina Sediqui
Chemistry Faculty Publications
Trimethylsilyl trifluoromethanesulfonate (TMSOTf) and a trialkylamine base promote both in situ enol silane/silyl ketene acetal formation and Mukaiyama aldol addition reactions between a variety of reaction partners in a single reaction flask. Isolation of the required enol silane or silyl ketene acetal is not necessary. For example, crossed aldol reactions between α-disubstituted aldehydes and non-enolizable aldehydes yield b- hydroxy aldehydes in good yield. In a related reaction, the common laboratory solvent ethyl acetate functions as both an enolate precursor and a green reaction solvent. When thioesters are employed as enolate precursors, high yields for additions to non-enolizable aldehydes are routinely …
An Overview Of Dynamic Heterogeneous Oxidations In The Troposphere, Elizabeth A. Pillar-Little, Marcelo I. Guzman
An Overview Of Dynamic Heterogeneous Oxidations In The Troposphere, Elizabeth A. Pillar-Little, Marcelo I. Guzman
Chemistry Faculty Publications
Due to the adverse effect of atmospheric aerosols on public health and their ability to affect climate, extensive research has been undertaken in recent decades to understand their sources and sinks, as well as to study their physical and chemical properties. Atmospheric aerosols are important players in the Earth’s radiative budget, affecting incoming and outgoing solar radiation through absorption and scattering by direct and indirect means. While the cooling properties of pure inorganic aerosols are relatively well understood, the impact of organic aerosols on the radiative budget is unclear. Additionally, organic aerosols are transformed through chemical reactions during atmospheric transport. …
Sintering-Induced Nucleation And Growth Of Noble Metal Nanoparticles For Plasmonic Resonance Ceramic Color, Nathan Dinh, Michael C. Leopold, Ryan Coppage
Sintering-Induced Nucleation And Growth Of Noble Metal Nanoparticles For Plasmonic Resonance Ceramic Color, Nathan Dinh, Michael C. Leopold, Ryan Coppage
Chemistry Faculty Publications
This study demonstrates the formation of nanoparticles (NPs) from metal salts within ceramic glazes, such that the use of this colorant technology is more accessible to artisans, employs less metal content, is less environmentally harmful, and allows for the use of traditional kilns. Gold NPs have been demonstrated to possess a specific, low material loading use as a ceramic glaze colorant via plasmon resonance. Pre-synthesized gold NPs that are added to ceramic glazes have been found to significantly change in size after firing in both reductive and oxidative atmospheres, but still maintain some size relationships and color properties. Unfortunately, it …
Oxidation Of N-Doped Multiwalled Carbon Nanotubes And Formation Of Discontinuous Spiraled Carbon Nanoribbons, Aman Preet Kaur, Mark S. Meier, Rodney Andrews, Dali Qian
Oxidation Of N-Doped Multiwalled Carbon Nanotubes And Formation Of Discontinuous Spiraled Carbon Nanoribbons, Aman Preet Kaur, Mark S. Meier, Rodney Andrews, Dali Qian
Chemistry Faculty Publications
The effects of five commonly used wet chemical oxidations were studied for the extent of oxidation of graphitized nitrogen-doped multiwalled carbon nanotubes (N-MWCNTs). KMnO4/ H2SO4 was the most potent oxidant, as it produced the highest fraction of oxygen-containing functional groups. Electron microscopy studies showed that the treatment of annealed N-MWCNTs (G-N-MWCNTs) with H2SO4/HNO3 and H2SO4/KMnO4 mixtures leads to interesting spiraled ribbon textures. A structural model, involving the stacking of coiled subunits to form a discontinuous carbon nanoribbon rather than a continuous ribbon is proposed to …
Undergraduate Research In Petrology Approached Through Computer Modeling Of Fabric Evolution In Igneous Rocks, Michael C. Leopold, M. J. Bonder, C. W. Holyoke, T. G.M. Krohn, R. V. Amenta
Undergraduate Research In Petrology Approached Through Computer Modeling Of Fabric Evolution In Igneous Rocks, Michael C. Leopold, M. J. Bonder, C. W. Holyoke, T. G.M. Krohn, R. V. Amenta
Chemistry Faculty Publications
Undergraduate research is an important part of the curriculum in many geology departments but, in recent years, it has become more difficult to attract students into projects dealing with solid-earth studies due to the limited employment prospects in these areas compared to those in environmental geology. This report describes how petrologic research can be made more attractive to students by an approach using C programming to model crystal growth and fabric development in poly crystalline solids. This topic has broad appeal to students in the other sciences as well as geology, and the computer skills learned have wide practical utility …
A Galactomannoglucan Derived From Agaricus Brasiliensis: Purification, Characterization And Macrophage Activation Via Mapk And Ikappab/Nfkappab Pathways, Yanqing Zhang, Danting Liu, Leilei Fang, Xiaotong Zhao, Aimin Zhou, Junbo Xie
A Galactomannoglucan Derived From Agaricus Brasiliensis: Purification, Characterization And Macrophage Activation Via Mapk And Ikappab/Nfkappab Pathways, Yanqing Zhang, Danting Liu, Leilei Fang, Xiaotong Zhao, Aimin Zhou, Junbo Xie
Chemistry Faculty Publications
In this study, a novel galactomannoglucan named as TJ2 was isolated from Agaricus brasiliensis with microwave extraction, macroporous resin, ion exchange resin and high resolution gel chromatography. TJ2 is composed of glucose, mannose and galactose in the ratio 99.2:0.2:0.6. Infrared spectra (IR), methylation analysis and nuclear magnetic resonance spectra indicated that TJ2 mainly contained a b-(1?3) – linked glucopyranosyl backbone. Interestingly, TJ2 significantly promoted RAW264.7 cell proliferation, and was able to activate the cells to engulf E. coli. In addition, TJ2 induced the expression of Interleukin 1b (IL-1b), Interleukin 6 (IL-6), tumor necrosis factor a (TNF-a) and cyclooxygenase-2 (Cox-2) in …
Sphingomyelin And Gm1 Influence Huntingtin Binding To, Disruption Of, And Aggregation On Lipid Membranes, Maxmore Chaibva, Xiang Gao, Pranav Jain, Warren A. Campbell, Shelli L. Frey, Justin Legleiter
Sphingomyelin And Gm1 Influence Huntingtin Binding To, Disruption Of, And Aggregation On Lipid Membranes, Maxmore Chaibva, Xiang Gao, Pranav Jain, Warren A. Campbell, Shelli L. Frey, Justin Legleiter
Chemistry Faculty Publications
Huntington disease (HD) is an inherited neurodegenerative disease caused by the expansion beyond a critical threshold of a polyglutamine (polyQ) tract near the N-terminus of the huntingtin (htt) protein. Expanded polyQ promotes the formation of a variety of oligomeric and fibrillar aggregates of htt that accumulate into the hallmark proteinaceous inclusion bodies associated with HD. htt is also highly associated with numerous cellular and subcellular membranes that contain a variety of lipids. As lipid homeostasis and metabolism abnormalities are observed in HD patients, we investigated how varying both the sphingomyelin (SM) and ganglioside (GM1) contents modifies the interactions between htt …
Palladium-Catalyzed Carbonyl Allylation Reactions Using Tin Chloride: A Mini-Review, Armando M. Guidote Jr, Mikael John A. Baltazar, Roy Kristian C. Yanela, Noriyuki Suzuki
Palladium-Catalyzed Carbonyl Allylation Reactions Using Tin Chloride: A Mini-Review, Armando M. Guidote Jr, Mikael John A. Baltazar, Roy Kristian C. Yanela, Noriyuki Suzuki
Chemistry Faculty Publications
The treatment of allylic alcohols as synthons of carbanions for carbonyl allylation reactions in the presence of a Pd-SnCl2 system has been one of the most interesting and most useful developments demonstrated by Yoshiro Masuyama and co-workers in the field of organic synthesis. The reaction makes use of palladium as an effective catalyst and tin (II) chloride as a low-valent reducing agent which also effectively transforms the allylic group to a nucleophilic group. The organic, as well as organometallic, chemistry of how the transformations occur and how the metals take part in the reaction is of great interest. These could …
Chalcone And Cinnamate Synthesis Via One-Pot Enol Silane Formation-Mukaiyama Aldol Reactions Of Ketones And Acetate Esters, C. Wade Downey, Hadleigh M. Glist, Anna Takashima, Samuel R. Bottum, Grant J. Dixon
Chalcone And Cinnamate Synthesis Via One-Pot Enol Silane Formation-Mukaiyama Aldol Reactions Of Ketones And Acetate Esters, C. Wade Downey, Hadleigh M. Glist, Anna Takashima, Samuel R. Bottum, Grant J. Dixon
Chemistry Faculty Publications
Aryl alkyl ketones, acetate esters, and acetamides undergo facile one-pot enol silane formation, Mukaiyama aldol addition, and dehydrosilyloxylation in the presence of an amine base and excess trimethylsilyl trifluoromethanesulfonate. The chalcone and cinnamate products are generally recovered in high yield. The relative stoichiometry of the trimethylsilyl trifluoromethanesulfonate and amine base reagents determines whether the reaction yields the β- silyloxy carbonyl product or the α, β -unsaturated carbonyl.