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Dms Air/Sea Flux And Gas Transfer Coefficients From The North Atlantic Summertime Coccolithophore Bloom, Christa Marandino, Warren J. De Bruyn, Scott Miller, Eric S. Saltzman

Biology, Chemistry, and Environmental Sciences Faculty Articles and Research

Dimethylsulfide (DMS) atmospheric and oceanic concentrations and eddy covariance air/sea fluxes were measured over the N. Atlantic Ocean during July 2007 from Iceland to Woods Hole, MA, USA. Seawater DMS levels north of 55 degrees N ranged from 3 to 17 nM, with variability related to the satellite-derived distributions of coccoliths and to a lesser extent, chlorophyll. For the most intense bloom region southwest of Iceland, DMS air/sea fluxes were as high as 300 mu mol m(-2) d(-1), larger than current model estimates. The observations imply that gas exchange coefficients in this region are significantly greater than those estimated using …

Syntheses And Evaluation Of Phthalocyanine Derivatives For Applications In Photodynamic And Boron Neutron Capture Therapies For Cancer, Hairong Li

LSU Doctoral Dissertations

Chapter I introduced the background of phthalocyanines including its physical properties and various synthetic methods of free-base and metallo-phthalocyanines. The background of PDT and BNCT was introduced and the objective of ideal sensitizers was described. Chapter II described the synthesis and characterization of a series of pyridiloxy-substituted zinc phthalocyanines with different length of alkyl groups. Pyridiloxy-substituted silica phthalocyanines bearing different associated axial ligands, were alkylated with methyl or PEG chains. Biological study was performed on these cationic pyridiloxy-substituted zinc phthalocyanines. Chapter III introduced the synthesis and photophysical properties of A3B-type zinc phthalocyanines conjugated with one or two cobalta-carborane cages. They …

Pyridinium Bisretinoids: Synthesis And Photoactivated Cytotoxicity, Junping Gao

Theses and Dissertations

This thesis discusses pyridinium bisretinoid compounds (PBRs), which were prepared for two purposes: 1) to use them as standards for detection of novel fluorophores in human RPE cells, which may be involved in age-related macular degeneration (AMD), and 2) to use them in the development of a targeted and triggered drug delivery system for cancer therapy. We prepared a selection of PBRs using a one-pot biomimetic method; synthesis, mechanisms for formation, and characterization of these compounds is described. We also explored the photoreactivity of three novel PBR compounds and found that these PBRs form oxidation products under blue-light irradiation. The …

Kinetic Studies Of The Hydrolysis Reactions Of Ruthenium (Iii) Complexes Him Trans-[Rucl₄(Im)₂] And Hind Trans-[Rucl₄(Ind)₂] By Uv-Visible Spectrophotometry, Pramod K. Nangunuri

Master's Theses and Doctoral Dissertations

The ruthenium complexes have gained importance in cancer research in recent times, as several cancers have developed resistance towards platinum compounds. Platinum compounds have severe adverse effects that limited their use towards a wide range of tumors.

Ruthenium complexes are considered as pro-drugs, as they transform into antitumor active species in the body by hydrolysis, redox reactions, and reactions with biologically occurring nucleophiles. My project involved the synthesis of two ruthenium complexes with different ligands and the study of the hydrolysis reactions under different pH at room temperature using UV-visible spectrophotometry.

These studies will enable us to understand how structural …

Drift Tube Ion Mobility Measurements For Thermochemistry, Kinetics And Polymerization Of Cluster Ions, Ridha Ben Mohsen Mabrouki

Theses and Dissertations

In this work, the Drift Tube Ion Mobility technique is used to study the hydrophobic hydration and solvation of organic ions and measure the thermochemistry and kinetics of ion-molecule reactions. Furthermore, an exploratory study of the intracluster polymerization of isoprene will be presented and discussed. The ion hydration study is focused on the C3H3+ cation1 and Pyridine▪+ radical cation.2 The chemistry of the cyclic C3H3+ cation1 has received considerable attention and continues to be an active area of research.3-7 The binding energies of the first 5 H2O molecules to c-C3H3+ were determined by equilibrium measurements. The measured binding energies of …

Design Synthesis And Evaluation Of Diterpenones As Potent Chemopreventive Agents For Aflatoxin B1 Induced Carcinogenesis In Human Liver Cells, Miguel Angel Zuniga

Theses and Dissertations

DESIGN, SYNTHESIS, AND EVALUATION OF DITERPENONES AS POTENT CHEMOPREVENTIVE AGENTS FOR AFB1 INDUCED CARCINOGENISIS IN HUMAN LIVER CELLS By Miguel A. Zuniga, Ph.D. A dissertation submitted in partial fulfillment of the requirements for the degree of Doctor of Philosophy at Virginia Commonwealth University. Major Director: Qibing Zhou, Ph.D Assistant Professor Department of Chemistry Terpene quinone methides (TPQMs) have been isolated from a variety of plants and show broad activities against bacteria, fungi, and cancerous cell lines. The biological activity has been attributed to the reactive electrophilic QM moiety, this structural feature has long been recognized as an intermediate in organic …

Synthesis And Properties Of Isoporphyrins And Related Derivatives For Application In Photodynamic Therapy, Sandra Celinah Mwakwari

LSU Doctoral Dissertations

Isoporphyrins are tautomers of porphyrins with an interrupted macrocyclic conjugation owing to the presence of a sp3 hybridized meso-carbon. Due to their absorption at long wavelengths (~800nm), isoporphyrins are potential candidates as photosensitizers in photodynamic therapy (PDT), a ternary modality of cancer treatment. They are also of biological interest due to their unique redox properties among porphyrin derivatives and could be a new class of near-IR dyes. Isoporphyrins are known to be unstable with respect to transformation back to the fully conjugated porphyrin chromophore except when the meso-carbon is geminally substituted and for this reason a detailed study of this …

The Spectral And Photophysical Characterization Of Water Solubilizing Metal Phthalocyanines For Highly Sensitive Detection In Biological Studies, Vera Tamisha Verdree

LSU Doctoral Dissertations

Efforts to improve the technology for DNA analyses stimulated the work presented here to develop a series of fluorescent probes that would aid in the increased multiplexing capabilities allowing the ability to detect multiple targets in a single measurement. Typically, spectral discrimination has been used to identify each DNA fragment in sequencing or diagnostic applications by means of unique emission properties from several labeling dyes. This has been accomplished with labels that fluoresce in the visible region. The limitations with these dyes is the broad emission profile making discrimination difficult, high intrinsic biological fluorescence and structural differences of the dyes …

Syntheseses [Sic] And Evaluation Of Porphyrin Derivatives For Applications In Medicine And In Material Science, Erhong Hao

LSU Doctoral Dissertations

Chapter 1 presents a concise introduction to porphyrins, especially on the synthesis of meso-tetraphenylporphyrins, which were synthesized during the course of my research and were used for further purposes in the following chapters. Chapter 2 describes the synthesis of a series of cobaltacarborane-porphyrin conjugates for the boron neutron capture therapy (BNCT) of tumors. Using an efficient and high yield ring-opening reaction, N-substituted porphyrins were also synthesized. The spectroscopic and structural properties of these compounds are presented. These high percentage boron and amphiphilic compounds are promising boron delivery agents for BNCT (prelimary cellular studies using some of these compounds have been …

Synthesis And Functionalizations Of Tetrapyrrole Derivatives, Lijuan Jiao

LSU Doctoral Dissertations

Chapter 1 of this Dissertation presents a brief overview of the history of tetrapyrrole derivatives and of their fundamental properties. Overviews of porphyrins, benzoporphyrins, chlorins and porphycenes are presented. Work presented in Chapter 2 through Chapter 4 mainly focuses on the syntheses and functionalization of chromophore-extended porphyrin derivatives. Several new synthetic routes for the syntheses and functionalizations of extended porphyrins either at the β-position or at the meso-position of porphyrin are developed. From these improved synthetic routes, the regio-selective syntheses of porphyrin derivatives are described. Chapter 2 mainly focuses on the syntheses of β,β'-fused methylenepropanoporphyrins and related porphyrin dimers. Chapter …

Spectroscopic Characterisation And Biological Applications Of Organotin(Iv) Derivatives Of 3-(N-Naphthylaminocarbonyl)-2-Propenoic Acid, Sajjad Ahmad, Moazzam H. Bhatti, Saqib Ali, Fiaz Ahmed

Turkish Journal of Chemistry

In an effort to develop new organotin materials for investigation and biocidal evaluation, a series of compounds with the general formula R_{4 - n}SnL_n (where R = CH_3, n-C_4H_9, C_6H_5, C_6H_5CH_2 and L = 3-(N-naphthylaminocarbonyl)-2-propenoic acid) were synthesised, and characterised by elemental analysis, IR, multinuclear (^1H, ^{13}C and ^{119}Sn) NMR, ^{119m}Sn Mössbauer spectroscopy and mass spectrometry. The biological activity of these compounds against various bacteria and fungi was investigated. All of the compounds were active against the fungi tested with a few exceptions. These compounds also showed significant antibacterial activity. LD_{50} data show that the investigated compounds have significant toxicity.

Synthesis, Spectroscopic (Ft-Ir, ^1h, ^{13}C, Mass Spectrometry), And Biological Investigation Of Five-Coordinated Germanium-Substituted Tricyclohexyl Antimony Dipropionates: Crystal Structure Of Tricyclohexylantimony Dibromide, Muhammad Kaleem Khosa, Muhammad Mazhar, Saqib Ali, Kieran C. Molloy, Sarim Dastgir, Farkhanda Shaheen

Turkish Journal of Chemistry

A series of five-coordinated germanium-substituted tricyclohexylantimony dipropionates have been synthesized and characterized by different instrumental techniques, such as elemental analyses, FT-IR, multinuclear NMR (^1H, ^{13}C) and mass spectrometry. These compounds have also been screened against different microbes and they showed good activity against different bacteria that was comparable to the reference drugs. The crystal structure of the precursor (C_6H_{11})_3SbBr_2 is reported here, which showed that the antimony atom in an asymmetric unit exists in trigonal bipyramidal geometry, having space group C2/c with the monoclinic crystal system.

Lead Optimization Of 7-Benzyloxy 2-(4′-Pyridylmethyl)Thio Isoflavone Aromatase Inhibitors, Bin Su, John C. Hackett, Edgar S. Diaz-Cruz, Young Woo Kim, Robert W. Brueggemeier

Chemistry Faculty Publications

Aromatase, the enzyme responsible for estrogen biosynthesis, is a particularly attractive target in the treatment of hormone-dependent breast cancer. The synthesis and biological evaluation of a series of 2-(4′-pyridylmethyl)thio, 7-alkyl- or aryl-substituted isoflavones as potential aromatase inhibitors are described. The isoflavone derivatives demonstrate IC50 values from 79 to 553 nM and compete with the endogenous substrate, androstenedione. Data supporting the ability of these analogs to suppress aromatase enzyme activity in the SK-BR-3 breast cancer cell line are also presented.

Rhizopine Synthesis – Potential Mediators For Nitrogen Fixation In Legume Plants, Venkat Reddy Guduru

Masters Theses

This research project focused on novel and efficient synthetic approaches of inosamine derivatives (rhizopines). The preparation of specific rhizopines would help elucidate the microbial pathway of rhizopine catabolism and degradation, and determine the role of corresponding genes during nitrogen fixation. We have investigated regio - and stereoselective transformations of myo-inositol derivative 28 utilizing an organostannane as key intermediate towards rhizopine 1a. The synthesis involved several protection and deprotection strategies to control competing reactivities of six hydroxyl groups of myo-inositol. Rhizopine 1a was prepared efficiently as a single isomer in 8 steps and 13% yield by controlling reactions …

Synthesis, Characterizations, And Evaluation Of New Reactive Two-Photon Absorbing Dyes For Two-Photon Excited Fluorescence Imaging Applications, Katherine J. Hales

Electronic Theses and Dissertations

Recent, cooperative advances in chemistry, biology, computing, photophysics, optics, and microelectronics have resulted in extraordinary developments in the biological sciences, resulting in the emergence of a novel area termed 'biophotonics'. The integrative and interdisciplinary nature of biophotonics cuts across virtually all disciplines, extending the frontiers of basic cellular, molecular, and biology research through the clinical and pharmaceutical industries. This holds true for the development and application of the novel imaging modality utilizing multiphoton absorption and its extraordinary contribution to recent advances in bioimaging. Intimately involved in the revolution of nonlinear bioimaging has been the development of optical probes for probing …

Part I : Isolation Of Dipentyl 2-(4-(Pentan-3-Yl) Phenyl) Malonate From Sanguisorba Officinalis Labill Part Ii: Synthesis Of A Novel Family Of Ethers Of Podocarpic Acid, Manjeera Yalavarty

Electronic Theses and Dissertations

The goal of part I of this thesis was to isolate pure anti cancer compounds from the Russian plant Sanguisorba officinalis. This plant was selected for investigation because it showed 100% activity against leukemia (L1210 mouse leukemia cells) during the preliminary screening of approximately 100 Russian plant extracts. This work has resulted in the isolation of novel compound 11 using traditional chromatography techniques. Compound 11 was characterized with spectroscopic techniques such as IR, 1H NMR, 13C NMR, DEPT, DQCOSY and MS. Compound 11 was assigned the structure dipentyl 2-(4-(pentan-3-yl) phenyl) malonate. The goal of part II of this thesis was …

Synthetic Development And Application Of Compounds With Biological Relevance, Jeffery Caleb Clark

LSU Doctoral Dissertations

Nature has provided a vast number of compounds that have medicinal application. The use of these compounds provided by nature however, is limited by the amount of a specific compound that nature provides. The synthesis of these molecules and their derivatives provides an even greater number of compounds for biological screening. Various pyrroles, the heterocyclic building blocks of porphyrins, can be prepared synthetically over several steps. The implementation of carboranes on pyrrole rings intrinsically provides substrates that can be converted into porphyrins bearing carborane substituents. The condensation of these carboranylpyrroles with carboranylaldehydes provides carboranylporphyrins bearing a higher order of carborane …

^{1}H, ^{13}C, ^{119}Sn Nmr, Mass, Mössbauer And Biological Studies Of Tri-,Di- And Chlorodiorganotin(Iv) Carboxylates, Hajra Masood, Saqib Ali, Mohummad Mazhar, Saira Shahzadi, Khadija Shahid

Turkish Journal of Chemistry

The reaction of 2-[(2,3-dimethylphenyl)amino]benzoic acid (HL) with tri- and diorganotin(IV) chlorides yielded complexes of the type R_{3}SnL and R_{2}SnL_{2} (R = n-C_{4}H_{9}, C_{6}H_{5}, C_{6}H_{5}CH_{2}, n-C_{8}H_{17}). The compounds R_{2}SnClL were obtained by a redistribution reaction between R_{2}SnL_{2} and R_{2}SnCl_{2}. All the compounds were characterized by CHN analysis, infrared, multinuclear NMR, mass and Mössbauer spectroscopy. The possible mode of carboxylate group bonding in solid as well as in solution is proposed on the basis of infrared, Mössbauer and NMR (^{1}H, ^{13}C, ^{119}Sn) spectroscopy.

Synthesis Of A Novel Family Of Amide Derivatives Of Podocarpic Acid, Dao Nguyen

Electronic Theses and Dissertations

As a class, amides are of great interest in biological studies and pharmaceutical application. In this work, podocarpic acid, a natural tricyclic diterpene, derived from Podocarpus species, has been employed to form a novel family of amide derivatives which will later be studied for their potential as new drug leads. Novel amide derivatives of podocarpic acid were synthesized from podocarpic acid in three steps. The first step involved methylation with dimethylsulfate to form methyl-O-methylpodocarpate. This step was followed by iodination with iodine to give iodomethyl-O-methylpodocarpate. Finally amidation with various aliphatic amides using a copper catalyst yielded four amide derivatives of …

Genome Analysis: Mutation Analysis Using Near Infrared Laser-Induced Fluorescence (Nir-Lif) And Single Molecule Detection In Microfluidic Devices, Musundi Ben Wabuyele

LSU Doctoral Dissertations

A number of genotyping methods have been developed for mutation analysis, each of which has its own unique advantage. DNA amplification via polymerase chain reaction (PCR) provides an unlimited supply of material for subsequent genetic analysis even in case where only a single copy of the DNA molecule is present in the sample. Research presented in this dissertation first examines the efficiency of in vitro amplification of single copy DNA with subsequent sequencing analysis of PCR product. The PCR products (amplicons) were investigated for possible alteration, distortions or mutations due to the amplification process. The sequencing data for single copy …

Artificial Peptides Containing Ca,A- Disubstituted Amino Acids: Synthesis, Conformational Studies, And Application As Β-Strand Mimics, Yanwen Fu

LSU Doctoral Dissertations

Short peptides containing C^α,α-dipropylglycine (Dpg) at alternating sequence positions were synthesized and examined for conformational behavior. Peptide assembly was performed using Fmoc-solid-phase chemistry where the coupling with PyAOP could be significantly enhanced at elevated temperature. Circular dichroism (CD) and NMR conformational studies revealed that incorporation of Dpg residues induced folded structures into peptides. It was observed that Dpg residues adopted helical conformation in a helix-promoting sequence. The resulting helical structure was comprised of consecutive β-turns whose structure was stabilized by salt bridge in aqueous solution. In this study, the preparation of sterically and polyfunctional C^α,α-disubstituted amino …

Structural And Functional Imaging With Carbon Nanotube Afm Probes, J. H. Hafner, Chin Li Cheung, A. T. Woolley, C. M. Lieber

Barry Chin Li Cheung Publications

Atomic force microscopy (AFM) has great potential as a tool for structural biology, a field in which there is increasing demand to characterize larger and more complex biomolecular systems. However, the poorly characterized silicon and silicon nitride probe tips currently employed in AFM limit its biological applications. Carbon nanotubes represent ideal AFM tip materials due to their small diameter, high aspect ratio, large Young’s modulus, mechanical robustness, well-defined structure, and unique chemical properties. Nanotube probes were first fabricated by manual assembly, but more recent methods based on chemical vapor deposition provide higher resolution probes and are geared towards mass production, …

High-Performance Liquid Chromatographic And Capillary Electrophoretic Enantioseparation Of Plant Growth Regulators And Related Indole Compounds Using Macrocyclic Antibiotics As Chiral Selectors, F. Hui, K. H. Ekborg-Ott, Daniel W. Armstrong

Chemistry Faculty Research & Creative Works

Enantioseparation of plant growth regulators, such as 3-(3-indolyl)-butyric acid, abscisic acid and structurally related molecules including a variety of substituted tryptophan compounds, has been achieved by HPLC and/or CE. The covalently bonded macrocyclic antibiotics, teicoplanin, ristocetin A and vancomycin, were used as chiral stationary phases (CSPs) in HPLC. Most of the racemates were baseline resolved in the reversed-phase mode (EtOH-H2O) using the teicoplanin CSP. The chiral recognition mechanism is discussed in regard to the structure of the analytes. In CE, the three aforementioned macrocyclic antibiotics were used as chiral additives in a phosphate run buffer. The effect of pH and …

Thermodynamic And Binding Studies Of Ligand-Carcinogen Dna Targets, Qianying Liang

Seton Hall University Dissertations and Theses (ETDs)

No abstract provided.

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.

Determination Of Selected Hydrocarbon Concentrations In Reformate Using Near Infrared Spectroscopy, Roy Roger Bledsoe Jr.

Theses, Dissertations and Capstones

Near infrared spectroscopy was used as a quantitative technique employing multiple linear regression and partial least squares regression for determining the concentration of hydrocarbon groups and individual hydrocarbons present in reformate, a refinery process stream. Models were generated for total aromatics, benzene, toluene, total xylenes and individual xylene isomers, ethylbenzene, total paraffins, n-hexane, n-heptane, total isoparaffins, isopentane, 2-methylhexane, total naphthenes, methylcyclopentane, and total olefins. Some models are being used with an on-line instrument to constantly monitor a reformate stream as it leaves the reforming unit, with a standard error of performance of 0.118 volume percent for the prediction …

Ionic Interaction Studies Of Bovine Copper, Zinc-Superoxide Dismutase, Hanan A. Hasan

Dissertations

No abstract provided.

Microwave Plasma Chemical Vapor Deposited Diamond Tips For Scanning Tunneling Microscopy, Sacharia Albin, Jianli Zheng, John B. Cooper, Weihai Fu, Arnel C. Lavarias

Electrical & Computer Engineering Faculty Publications

Diamond microparticles were grown on etched tungsten wires using a microwave plasma-assisted chemical vapor deposition process. The apexes on cubo-octahedral particles bound by {100} and {111} facets were effectively used as tunneling tips for scanning tunneling microscopy. The atomically resolved surface image of highly oriented pyrolytic graphite was acquired. Tunneling characteristics revealed a higher electron emission from the diamond tips than that from the platinum–iridium tips. The same diamond tips were used to produce surface indentation and its image. © 1997 American Institute of Physics.

The Lipooligosaccharides Of Haemophilus Ducreyi Are Highly Sialylated, William Melaugh, A A. Campagnari, B W. Gibson

Chemistry Faculty Publications

The major lipooligosaccharides of the sexually transmitted pathogen Haemophilus ducreyi 35000 have been previously found to terminate in N-acetyllactosamine and sialyl-N-acetyllactosamine, Neu5Ac alpha 2-->3Gal beta 1-->4GlcNAc (W. Melaugh, N. J. Phillips, A. A. Campagnari, M. V. Tullius, and B. W. Gibson, Biochemistry 33: 13070-13078, 1994). In this study, mass spectrometry and composition analyses have shown that the lipooligosaccharides from three other H. ducreyi strains also contain N-acetyllactosamine and are highly sialylated (approximately 30 to 50%), although one African strain was found to contain neither of these structural features.

Na+-H+ Exchange And Na+-Li+ Exchange In Human Erythrocytes: An Nmr Investigation, Yuling Chi

Dissertations

No abstract provided.