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High-Performance Liquid Chromatographic Separation Of Enantiomers Of Unusual Amino Acids On A Teicoplanin Chiral Stationary Phase, Antal Péter, Gabriella Török, Daniel W. Armstrong

Chemistry Faculty Research & Creative Works

A glycopeptide antibiotic, teicoplanin, was used as chiral stationary phase for the high-performance liquid chromatographic (HPLC) separation of enantiomers of more than 30 unnatural amino acids, such as phenylalanine and tyrosine analogues and analogues containing 1,2,3,4-tetrahydroisoquinoline, tetraline, 1,2,3,4-tetrahydro-2-carboline, cyclopentane, cyclohexane, cyclohexene, bicyclo[2.2.1]heptane or heptene skeletons. Excellent resolutions were achieved for most of the investigated compounds by using a hydro-organic mobile-phase system. The effects of organic modifier content, temperature and flow-rate on the resolution were investigated and the conditions of separation were optimized.

Chiral Separations Of Indan, Tetralin And Benzosuberan Derivatives By Capillary Electrophoresis, Kyung Hyun Gahm, Jauh Tzuoh Lee, Lisa W. Chang, Daniel W. Armstrong

Chemistry Faculty Research & Creative Works

Several indan, tetralin and benzosuberan derivatives of diverse polarities were enantio-resolved by the use of sulfated β-cyclodextrins (CDs) or mixtures of sulfated β-CDs and γ-CD as chiral additives in capillary electrophoresis. Mixtures of sulfated 13-CDs and hydroxypropy1 β- CDs were also successfully utilized for enantiomeric and diastereomeric separations of some of the tetralin derivatives with two stereogenic centers. Both neutral and anionic analytes were resolved in the reversed electrophoretic polarity mode. Cationic amino derivatives of indan and tetralin were enantio-resolved in the conventional electrophoretic polarity mode.

Influences Of Acid Mine Drainage On Water Chemistry Of Blackwater River Watershed, Carla C. Morato-Lara

Theses, Dissertations and Capstones

Acidic mine drainage flow from active and abandoned coal mines has been a major source of water pollution in the Appalachian Mountain region of the eastern USA. Water samples were collected and analyzed from Blackwater River watershed during 2 years (September 1996 - May 1998). The water quality measurements determined that the Beaver Creek and North Fork tributaries were affected by acid mine drainage but not Yellow Creek. Beaver Creek and North Fork stations had high sulfate and manganese markers of acid mine drainage, whereas Yellow Creek was slightly acidic with low sulfate and manganese. North Fork was the primary …

Arginine To Glutamine Substitutions In The Fourth Module Of Xenopus Interphotoreceptor Retinoid-Binding Protein, Mark S. Braiman, Claxton A. Baer, Ellen E. Van Niel, Jeffrey W. Cronk, Michael T. Kinter, Nicholas E. Sherman, Federico Gonzalez-Fernandez

Chemistry - All Scholarship

Interphotoreceptor retinoid-binding protein (IRBP) is unusual for a lipid-binding protein in that its gene is expressed uniquely by cells of photoreceptor origin and consists of four homologous repeats, each coding for a module of~300 amino acid residues. All-trans retinol binding domains, which appear to be present in each module, are composed of conserved hydrophobic regions [Baer et al, Exp Eye Res 1998; 66:249-262]. Here we investigate the role of highly conserved arginines contained in these regions.

Vibrational Sum Frequency Spectroscopy Of Surfactants And Phospholipids Monolayers At Liquid-Liquid Interfaces, B. L. Smiley, R. A. Walker, D. E. Gragson, T. E. Hannon, G. L. Richmond

Chemistry and Biochemistry

Work from our laboratory on vibrational sum frequency spectroscopic investigations of molecular ordering at the carbon tetrachloride-water interface is reviewed. Simple charged surfactants adsorbed at the liquid-liquid interface are seen to induce alignment of interfacial water molecules to a degree which is dependent on the induced surface potential. Saturation of water molecule alignment occurs at a surfactant surface concentration corresponding to a calculated surface potential of approximately 160 mV. In complementary studies, the relative degree of hydrocarbon chain ordering within monolayers of symmetric phosphatidylcholines of different chain lengths is inferred by the relative signal contributions of the methyl and methylene …

The Total Synthesis Of A Conformationally Constrained Organophosphorus Analog Of Acetycholine, Justin Mergott '98

Honors Projects

We propose the total synthesis of a conformationally constrained organophosphorus analog of acetylcholine (5, Scheme 5). This compound will contain two crural centers, one being the phosphorus atom and the other being the pyrrolidine ring carbon beta to the phosphorus atom. The chiral beta carbon is conformationally constrained because it is part of the pyrrolidine ring. Studies with such a compound should allow us to make substantial progress towards the clarification of the stereospecificity of AChE inhibition by OP compounds and eventually help us understand more about the structure of the AChE active site. The synthesis begins with Cbz-L-proline methyl …

Synthesis And Characterization Of A Trypsin Inhibitor, Eric L. Schneider

Honors Theses, 1963-2015

Inhibitors of biological enzymes are frequently produced by mimicking the molecular structure of the enzyme's natural substrate. Because of the extensive studies that have already been performed on the trypsin enzyme, its natural substrates and its mode of interaction with them are well understood. By finding an easily synthesized molecule to inhibit the trypsin enzyme, college level laboratory experiments could be designed and integrated into organic chemistry and biochemistry courses. In this project, a possible trypsin inhibitor molecule, 4-fluorobenzylaimine, was chosen based on its similarity to the natural trypsin substrates and because it has been predicted through computational studies to …

Environmental And Botanical Controls On Peatification - A Comparative Study Of Two New Zealand Restiad Bogs Using Py-Gc/Ms, Petrography And Fungal Analysis, Tomasz K. Kuder, Michael A. Kruge, J C. Shearer, S L. Miller

Department of Earth and Environmental Studies Faculty Scholarship and Creative Works

This study shows that chemical properties of two restiad species, Empodisma minus and Sporadanthus traversii, may contribute to their success as peat-formers in a climate of the North Island of New Zealand which is not conducive to raised mire development. Unlike Sphagnum, the equivalent northern hemisphere peat-former, restiads possess lignin in their tissues. In addition, the presence of non-lignin polyphenols (including tannins and phenolic acids) in restiads may be an important factor in peat formation due to the allelopathic decay retardation. Patterns of degradation of plant biopolymers have been examined and the pathway of degradation of monocotyledons (loss …

Fuel Cells, Frederick J. Munster Jr.

Maine Collection

Fuel Cells

by Frederick J. Munster Jr.

Edited by: Mr. Christopher Carroll

Maine Department of Economic Development, Augusta, Maine, 1998.

Contents: Hydrogen / Hydrogen Safety / Electrolysis / Electrolyzers / History of Fuel Cells / How Fuel Cells Operate / Fuel Cell Types / Fuel Cell Electrochemistry / Power Systems / Fuel Cells in Transportation / Hydrogen Powered Internal Combustion Engines / Home, Garden, Education and Industry / For More Information / Glossary / References

Alternatives To Nitroprusside, William T. Hiscock

Honors Theses

Any transition metal nitrosyl complex may release nitric oxide and thus has potential as a vasodilator. Nitroprusside, Na2[Fe(CN)5(NO)], is currently used, but dosages are limited because of the potential release of cyanide. Research in our group has been directed towards the synthesis of iron and ruthenium complexes containing the nitrosyl ligand and polypyridyl coligands such as 2,2-dipyridyl (bpy) and 2,2': 6',2"-terpyridine (tpy). These coligands are much less toxic than cyanide. Both [(bpy)(tpy)Fe(NO)]3+ and [(bpy)(tpy)Ru(NO)]3+ have been synthesized and characterized using infrared and ultraviolet spectroscopy, conductivity, and magnetic susceptibility. Along with the search for other possible polydentate coligands, is the search …

Approaches And Methodologies For The Synthesis Of Aromatic Natural Products, Christina A. Goudreau

Honors Theses

Chemists have been captivated by the ability of most natural products to exhibit biological activity which in effect has made them very attractive to pharmaceutical companies. Many over-the-counter drugs such as aspirin were first extracted from natural products and are now an integral part of most of our lives. More importantly, certain drugs such as taxol, which is used to treat breast cancer, initially came from the bark of a yew tree. Extracting these substances from their natural source and using them medicinally at the demand of the consumers would result in the destruction of the natural habitat. Oftentimes, the …

Comparison Of Different Production Processes For Bioethanol, B. Çaylak, Fazilet Vardar Sukan

Turkish Journal of Chemistry

In this study, ethanol was produced with the microorganism {\em Saccharomyces cerevisiae} by using sucrose as a substrate. Batch processes were tested by using the same substrate, microorganism and medium composition. {\em Saccharomyces cerevisiae}, used in the free form in the first group of experiments, was immobilized by different methods. In the second group of experiments agar, sponge and a natural material called luffa cylindrica fiber were used as support materials. The batch processes with free and immobilized microorganisms were compared with respect to efficiency and yield.

Kinetic Studies Of The Thermal Decomposition Of Di- And Tri-Organotin Derivatives Of 1-Nitroso-2-Naphthol, Saqib Ali, Moazzam H. Bhatti, Sohail Mahmood, Muhammad Mazhar, M. Saleem Khalid, Nazar Hussain

Turkish Journal of Chemistry

The di- and tri-organotin complexes of general formula R$_2$SnL$_2$ and R$_3$SnL where R = C$_4$H$_9$, C$_6$H$_5$, C$_6$H$_5$CH$_2$, C$_6$H$_{11}$ and L=1-nitroso-2-naphthol, were subjected to thermal decomposition by means of thermogravimetry (TG). The decomposition occurred in steps and the kinetics of every set of reactions were determined using the method described by Coats and Redfern. These results were analysed to establish the decomposition kinetics and hence to calculate activation energies. The activation energies were also determined by applying the method described by Horowitz, which yielded comparable results.

Patterns Of Organochlorine Pesticide Contamination In Neotropical Migrant Passerines In Relation To Wintering Range And Wintering Habitat, Jeffrey A. Klemens '98

Honors Projects

Seventy-two Neotropical migrant passerines were analyzed for the presence of 17 organochlorine pesticide residues (aldrin; alpha-BHC; beta-BHC; gamma-BHC; delta-BHC; p,p'-DDD; p,p'-DDE; p,p'-DDT; dieldrin; endosulfan I; endosulfan II; endosulfan sulfate; endrin; endrin aldehyde; heptachlor- heptachlor epoxide; methoxychlor) using standard method of gas chromatography applied to bird tissues. Individuals were colIected along the Mississippi River during May 1996 and represent 11 species (Catharus ustulatus; Geothlypis trichas; Protonotaria citrea; Mniotilta varia; Contopus virens; Dendroica petechia; Ernpidonax minimus; Passerina cyanea; Myiarchus crinitus; Vireo gilvus). The contaminants most frequently detected were p,p'-DDE, dieldrin, and heptachlor epoxide. No significant difference was found between male and female …

Ab Initio Study Of Formazan And 3-Nitroformazan, G. Buemi, F. Zuccarello, P. Venuvanalingam, M. Ramalingam, Salai Cheettu Ammal

Faculty Publications

Formazan and 3-nitroformazan have been investigated at abinitio level (MP2/6-31G** and B3LYP/6-31G**) in all their possible conformations, for studying the various possibilities of intramolecular hydrogen bonding formation. The trans-syn-s-cis (TSSC), known also asyellowform, has been found to be the most stable conformer (at least in the gas phase) in both compounds. This particular structure is strongly stabilized by a N–H···N hydrogen bridge, which gives rise to a hexatomic chelate ring, with the possibility of a proton transfer process.This closely resembles that of malondialdehyde, previously studied, in the evolution of the …

Mea Culpa: Formal Education And The Dis-Integrated World., Brian P. Coppola, Douglas S. Daniels

Chemistry Faculty Publications

Formal education has removed itself so far from any truly integrated view of the Natural World that fragmentation and certainty are prevailing ethics. Technological progress has resulted in increased specialization within academic disciplines and their concurrent separation from each other. Knowledge is extracted from a fully integrated world, but is examined and defined by the 'dis-integrated' objectives.

Determination Of The Protonation Constants Of 2-[4-Dimethylaminocinnamalamino] Benzoic Acid (Dacab) In Dioxane - Water Medium And Preparation Of Some Of Its Transition Metal Complexes, Mustafa Yalçin, Harun Mutluay, Hüsnü Cankurtaran

Turkish Journal of Chemistry

In this study, the Schiff base 2-[4-Dimethylaminocinnamalamino]- benzoic acid [(CH$_3$)$_2$N.C$_6$H$_4$.CH:CH.N.C$_6$H$_4$.COOH] (DACAB) was prepared by the reaction of 2-Aminobenzoic acid with p-Dimethylaminocinnamaldehyde. The protonation constants of the ligand were determined in a 50\% (v/v) dioxane - water medium using the Irving-Rossotti and PKAS-BEST computer methods. The complexes of Fe(III), Co(II), Ni(II), Cu(II) with DACAB were synthesized and the structures of these complexes were elucidated by means of data obtained from elemental analysis, using IR, $^1$H-NMR methods. The magnetic properties of the solid complexes were measured.

Nano-Engineering Of Molecular Films By Self-Assembly And Langmuir-Blodgett Techniques, Erwin P. Enriquez

Chemistry Faculty Publications

The availability of sophisticated and ultra-sensitive analytical tools and the maturity of organic synthesis have opened new possibilities for fabrication of molecular materials designed at the nanometer scale. Presently, the most promising and widely investigated methodologies are the self-assembly and Langmuir-Blodgett procedures. The former relies on the strong, preferential affinity of specific functional groups to solid surfaces, whereas the latter involves transfer of pre-formed mono layers at the air-water interface onto solid substrates. These techniques and their recent applications are reviewed.

Fatty Acid Composition And Cholesterol Content Of Some Turkish Fish Species, Sedat İmre, Serap Sağlik

Turkish Journal of Chemistry

It is well known that fish lipids are effective against cardiovascular diseases due to their high contents of polyunsaturated omega-3 (n-3) fatty acids. In order to determine a suitable fish diet, the fatty acid compositions and total lipid and cholesterol contents of 9 common fish species obtained from the central fish market in Ğstanbul were determined. Palmitic (C-16:0) and oleic acid (C-18:1) were the predominant saturated and monounsaturated fatty acids. The predominant polyunsaturated fatty acids were eicosapentaenoic (C-20:5) acid and docosahexaenoic (C-22:6) acid. The amounts of cholesterol in fish lipids did not differ significantly. Sardine ({\it Sardina pilchardus}) and mackerel …

The Evolution Of Chiral Stationary Phases For Liquid Chromatography, Daniel W. Armstrong

Chemistry Faculty Research & Creative Works

The development of effective chiral stationary phases (CSPs) and separation strategies for the liquid chromatographic (LC) resolution of enantiomers has been beneficial to many scientific disciplines. Over the last decade the number and type of CSPs has expanded tremendously. Not only have new classes of chiral selectors been introduced, but also many of the first CSPs have been changed and/or improved. The second or third generation of a CSP often can be different from the original. This can be confusing and intimidating to someone just entering the area of LC enantiomeric separations. Fortunately, all CSPs can be categorized in one …

Metathesis-Based Synthesis Of Jasmonate And Homojasmonate Lactones, Candidates For Extracellular Quorum Sensing Molecules In Candida Albicans, Su C. Cho, Patrick Dussault, Amber D. Lisec, Ellen C. Jensen, Kenneth W. Nickerson

Department of Chemistry: Faculty Publications

Ring-closing metathesis of jasmonate esters is shown to provide a rapid entry to jasmonate lactones. The lactones were investigated as possible quorum sensing molecules for the fungi Candida albicans. Assays demonstrated no effect on fungal morphology at concentrations up to 96 mM.

Ab Initio And Dft Investigations Of Lithium/Hydrogen Bonded Complexes Of Trimethylamine, Dimethyl Ether And Dimethyl Sulfide, Salai Cheettu Ammal, P. Venuvanalingam

Faculty Publications

Ab initio and DFT computations have been carried out on LiF and HF complexes of a set of n-donors viz. trimethylamine, dimethyl ether and dimethyl sulfide with a 6-31++G(d,p) basis set. The effect of correlation has been included with MP2, MP4 and DFT calculations. NBO analyses of the wavefunctions have been performed to examine the intermolecular interaction at the orbital level. Calculations reveal that these donors form strong n→σ* complexes and computed binding energies of the (CH₃)₂O···HF complex agree very well with the experimental binding energies from IR spectroscopy. LiF forms stronger complexes than HF, …

Novel Synthetic Route To 5-Substituted Indoles, Helen Y. Chen

Master's Theses

No abstract provided.

The CuA Center Of A Soluble Domain From Thermus Cytochrome Ba3. An Nmr Investigation Of The Paramagnetic Protein. A Proton Nmr Study Of The Paramagnetic Active Site Of The CuA Variant Of Amicyanin, Richard C. Holz

Chemistry Faculty Research and Publications

No abstract provided.

Inactivation Of Soybean Peroxidase During Sodium Azide Oxidation: A Comparative Study, Mohamed Yehia Zakaria Aboul Eish

Dissertations and Theses @ UNI

Azide ion is a mechanism-based inactivator of a number of peroxidases. However, there are often variations in the manner in which inactivation occurs. Soybean Peroxidase (SBP) is found in the plant's seed coat. Unlike many other peroxidases, a single enzyme rather than several isozymes are produced thus making more simple the purification and characterization of the enzyme. In this research it was shown that, as with other peroxidases, SBP is inactivated by azide during turnover. During azide oxidation SBP forms a ferrous-NO intermediate. In this respect, SBP is similar to the lignin peroxidases from Phanerochaete chrysosporium which also form ferrous-NO …

Bioremediation Of Soil Contaminated With Explosives, Catherine A. Axtell

Dissertations and Theses @ UNI

Bioremediation of contaminated soil and water has been the topic of considerable research interest. White rot fungi have recently been proposed for use in biodegradation of explosives. The explosives, TNT, RDX and HMX are integral components of the manufacture of munitions. The wastes from the production of these and other explosives have been discharged into the surrounding environment resulting in contamination. Phanerochaete chrysosporium and strain F600, a proprietary white rot fungus developed by Mycotech Corporation, were studied with regard to their ability to degrade TNT, HMX and RDX in liquid cultures and in soil. Laboratory studies demonstrated that P. chrysosporium …

Paramagnetic Nuclear Magnetic Resonance (Nmr) Studies On The Calcium Binding Site Of [Alpha]-Lactalbumin, Thomas Kurt Ritter

Dissertations and Theses

Paramagnetic NMR has drawn interest as a technique for extending the range of systems that can be investigated. The purpose of this study was to determine whether a combination of paramagnetic two-dimensional and relaxation techniques allows for assigning resonances corresponding to residues forming the metal binding site of proteins in which the metal is coordinated exclusively by amino acid side chains and which have been previously inaccessible to assignment.

α-Lactalbumin (LA) is a calcium binding protein with relatively broad NMR signals; this broadness has prevented complete assignment. LA has been the subject of many studies, because it can form a …

Heme Transfer Reactions: An Important Prerequisite For Synthetic Oxygen Carriers, Jan Paul, Wenhua Chen, Per-Ingvar Ohlsson, Michael Smith

Turkish Journal of Chemistry

Electronic changes of iron- and metal free porphyrins are reviewed in light of their importance to modify the ferri/ferro reduction potential and energy dissipation between ligated carbon monoxide and the porphyrin chelate. Substitutions at positions 2 and 4 are effective ways to exercise this influence. Other measures include exposure to water and modifications of axial ligation, including the \lq three-ligand' case. These measures will also influence the stability of recombined hemin-protein entities, as apparent from the kinetics of heme-transfer from a modified donor protein to apomyoglobin, but the stability appears to be related to the bulkiness of 2,4-substitutional groups rather …

Reactions Of 4-Amino-4,5-Dihydro-1h-1,2,4-Triazol-5-Ones And 4-Amino-4h-1,2,4-Triazoles With Some Carboxylic Acid Anhydrides, Şule Bahçeci̇, Nurhan İnce, Asun İki̇zler

Turkish Journal of Chemistry

3-Alkyl(Aryl)-4-tetrachlorophthalimido-4,5-dihydro-1H-1,2,4-triazol-5-ones (2) and 3-alkyl(aryl)-4-(1,8-naphthalimido)-4,5-dihydro-1H-1,2,4-triazol-5-ones (3) were synthesized from the reactions of 3-alkyl(aryl)-4-amino-4,5-dihydro-1H-1,2,4-triazol-5-ones (1) with tetrachlorophthalic anhydride and 1,8-naphthalic anhydride, respectively. In addition, the reactions of 4-amino-4H-1,2,4-triazoles (4) with succinic anhydride and phthalic anhydride were studied.

Determination Of Structure-Toxicity Relationship Of Amphiprotic Compounds By Means Of The Inhibition Of The Dehydrogenase Activity Of Pseudomonas Putida, Ş. Gül, D. Öztürk

Turkish Journal of Chemistry

Aliphatic and aromatic alcohols are amphiprotic compounds which have both polar and nonpolar parts in their structure. These compounds were studied with respect to the nonreactive toxic effects on the microorganism {\it Pseudomonas putida}. The toxicity of these chemicals to aerobic bacterium {\it P. putida} was measured in terms of inhibition of dehydrogenase activity. The test results, expressed as concentration of chemicals 50\% effective in inhibition (IC$_{50}$), were correlated with their physicochemical properties such as aqueous solubility (S) and octanol-water partition coefficient (P).