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Chemistry

Cleveland State University

2009

Articles 1 - 24 of 24

Full-Text Articles in Physical Sciences and Mathematics

Highly Nitrated Cyclopropanes As New High Energy Materials: Dft Calculations On The Properties Of C3H6−N(No2)N (N=3–6), Aloysus K. Lawong, David W. Ball Dec 2009

Highly Nitrated Cyclopropanes As New High Energy Materials: Dft Calculations On The Properties Of C3H6−N(No2)N (N=3–6), Aloysus K. Lawong, David W. Ball

Chemistry Faculty Publications

As part of a continuing study of new potential high energy materials, here we present results of calculations on cyclopropane molecules with three or more nitro groups. DFT calculations suggest that all molecules can exist as minimum-energy stationary states. Energy calculations indicate that some nitrocyclopropanes have a specific enthalpy of decomposition in excess of 8kJg−1, suggesting that they be explored as new potential high energy materials.

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Double Superhelix Model Of High Density Lipoprotein, Zhiping Wu, Valentin Gogonea, Xavier Lee, Mathew A. Wagner Dec 2009

Double Superhelix Model Of High Density Lipoprotein, Zhiping Wu, Valentin Gogonea, Xavier Lee, Mathew A. Wagner

Chemistry Faculty Publications

High density lipoprotein (HDL), the carrier of so-called “good” cholesterol, serves as the major athero-protective lipoprotein and has emerged as a key therapeutic target for cardiovascular disease. We applied small angle neutron scattering (SANS) with contrast variation and selective isotopic deuteration to the study of nascent HDL to obtain the low resolution structure in solution of the overall time-averaged conformation of apolipoprotein AI (apoA-I) versus the lipid (acyl chain) core of the particle. Remarkably, apoA-I is observed to possess an open helical shape that wraps around a central ellipsoidal lipid phase. Using the low resolution SANS shapes of the protein …

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Lead Optimization Of Cox-2 Inhibitor Nimesulide Analogs To Overcome Aromatase Inhibitor Resistance In Breast Cancer Cells, Bin Su, Shiuan Chen Dec 2009

Lead Optimization Of Cox-2 Inhibitor Nimesulide Analogs To Overcome Aromatase Inhibitor Resistance In Breast Cancer Cells, Bin Su, Shiuan Chen

Chemistry Faculty Publications

A series of COX-2 selective inhibitor nimesulide derivatives were synthesized. Their anti-cell proliferation activities were evaluated with a long-term estrogen deprived MCF-7aro (LTEDaro) breast cancer cell line, which is the biological model of aromatase inhibitor resistance for hormone-dependent breast cancer. Compared to nimesulide which inhibited LTEDaro cell proliferation with an IC50 at 170.30 μM, several new compounds showed IC50 close to 1.0 μM.

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Synthesis And Cytotoxic Analysis Of Some Disodium 3Β,6Β-Dihydroxysterol Disulfates, Jianguo Cui, Hui Wang, Yi Xin, Aimin Zhou Dec 2009

Synthesis And Cytotoxic Analysis Of Some Disodium 3Β,6Β-Dihydroxysterol Disulfates, Jianguo Cui, Hui Wang, Yi Xin, Aimin Zhou

Chemistry Faculty Publications

Disodium 3β,6β-dihydroxy-5α-cholestane disulfate (1) was synthesized in 4 steps with a high overall yield from cholesterol. First, cholesterol (4a) was converted to cholest-4-en-3,6-dione (5a) via oxidation with pyridinium chlorochromate (PCC) and then 5a was reduced by NaBH4 in the presence of NiCl2 to produce cholest-3β,6β-diol (6a). The reaction of 6a with the triethylamine-sulfur trioxide complex generated diammonium 3β,6β-dihydroxy-5α-cholestane disulfate (7a) and the treatment of 7a by cation exchange resin 732 (sodium form)(Na+) yielded the target steroid 1. Disodium 24-ethyl-3β,6β-dihydroxycholest-22-ene disulfate (2) and disodium 24-ethyl-3β,6β-dihydroxycholestane disulfate (3) were synthesized using a similar method. The cytotoxicity of these compounds against Sk-Hep-1 (human …

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Determination Of 6-Benzylthioinosine In Mouse And Human Plasma By Liquid Chromatography–Tandem Mass Spectrometry, Lan Li, Yan Xu, David N. Wald, William Tse Nov 2009

Determination Of 6-Benzylthioinosine In Mouse And Human Plasma By Liquid Chromatography–Tandem Mass Spectrometry, Lan Li, Yan Xu, David N. Wald, William Tse

Chemistry Faculty Publications

This paper described the development and validation of a liquid chromatography–tandem mass spectrometry (LC–MS/MS) method for the quantitative determination of 6-benzylthioinosine (6BT), a novel myeloid leukemia differentiation-inducing agent, in mouse and human plasma. In this method, 2-amino-6-benzylthioinosine (2A6BT) was used as internal standard and ethyl acetate was used as organic solvent for the extraction of 6BT and internal standard from plasma samples. The extracted samples were separated on YMC ODS-AQ® column (2.0 mm × 50 mm), and the eluates from the column were monitored by the positive-electrospray-ionization tandem mass spectrometer (ESI+-MS/MS). Quantification of 6BT by internal calibration with 2A6BT was …

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Synthesis And Evaluation Of Some Steroidal Oximes As Cytotoxic Agents: Structure/Activity Studies (Ii), Jianguo Cui, Lei Fan, Yanmin Huang, Yi Xin, Aimin Zhou Nov 2009

Synthesis And Evaluation Of Some Steroidal Oximes As Cytotoxic Agents: Structure/Activity Studies (Ii), Jianguo Cui, Lei Fan, Yanmin Huang, Yi Xin, Aimin Zhou

Chemistry Faculty Publications

Hydroximinosteroids isolated from marine sponges display a variety of biological functions including cytotoxicity and anti-virus. In this study, we synthesized a series of hydroximinosteroid derivatives with a different functional group on the ring A or B and various side chains at position 17, and analyzed the cytotoxicity of these compounds against sk-Hep-1, H-292, PC-3 and Hey-1B cancer cells. Our results revealed that although a cholesterol-type side chain at position 17 is required for the biological activity of the compounds as we previously confirmed, elimination of the 4,5-double bond augmented the cytotoxic activity for the steroidal oximes. In addition, the presence …

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A Cox-2 Inhibitor Nimesulide Analog Selectively Induces Apoptosis In Her2 Overexpressing Breast Cancer Cells Via Cytochrome C Dependent Mechanisms, Bin Chen, Bin Su, Shiuan Chen Jun 2009

A Cox-2 Inhibitor Nimesulide Analog Selectively Induces Apoptosis In Her2 Overexpressing Breast Cancer Cells Via Cytochrome C Dependent Mechanisms, Bin Chen, Bin Su, Shiuan Chen

Chemistry Faculty Publications

Epidemiological and animal model studies have suggested that non-steroidal anti-inflammatory drugs (NSAIDs) can act as chemopreventive agents. The cyclooxygenase-2 (COX-2) inhibitor nimesulide shows anti-cancer effect in different type of cancers. In the current study, five breast carcinoma cell lines were used to explore the anti-cancer mechanisms of a nimesulide derivative compound 76. The compound dose dependently suppressed SKBR-3, BT474 and MDA-MB-453 breast cancer cell proliferation with IC50 of 0.9 μM, 2.2 μM and 4.0 μM, respectively. However, it needs much higher concentrations to inhibit MCF-7 and MDA-MB-231 breast cancer cell growth with IC50 at 22.1 μM and 19.6 μM, respectively. …

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Cholesterol Levels And Activity Of Membrane Bound Proteins: Characterization By Thermal And Electrochemical Methods, Noufissa Zanati, Michael Ellen Mathews, Perera N. Indika, John J. Moran, Jean A. Boutros, Alan T. Riga, Mekki Bayachou Jun 2009

Cholesterol Levels And Activity Of Membrane Bound Proteins: Characterization By Thermal And Electrochemical Methods, Noufissa Zanati, Michael Ellen Mathews, Perera N. Indika, John J. Moran, Jean A. Boutros, Alan T. Riga, Mekki Bayachou

Chemistry Faculty Publications

The long-term goal of this investigation is to study the effects of increased cholesterol levels on the molecular activity of membrane-bound enzymes such as nitric oxide synthase, that are critical in the functioning of the cardiovascular system. In this particular investigation, we used differential scanning calorimetry (DSC) and dielectric thermal analysis (DETA) to study the effect of added cholesterol on melting/recrystallization and dielectric behavior, respectively, of phosphatidylcholine (PC) bilayered thin films. We also used electrochemical methods to investigate the effect of added cholesterol on the redox behavior of the oxygenase domain of nitric oxide synthase as a probe embedded in …

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Reductive Decomposition Of A Diazonium Intermediate By Dithiothreitol Affects The Determination Of Nos Turnover Rates, Perera N. Indika, Talal Sabbagh, Jean A. Boutros, Mekki Bayachou May 2009

Reductive Decomposition Of A Diazonium Intermediate By Dithiothreitol Affects The Determination Of Nos Turnover Rates, Perera N. Indika, Talal Sabbagh, Jean A. Boutros, Mekki Bayachou

Chemistry Faculty Publications

Accurate determination of nitrite either as such or as the breakdown product of nitric oxide (NO) is critical in a host of enzymatic reactions in various settings addressing structure–function relationships, as well as mechanisms and kinetics of molecular operation of enzymes. The most common way to quantify nitrite, for instance in nitric oxide synthase (NOS) mechanistic investigations, is the spectrophotometric assay based on the Griess reaction through external standard calibration. This assay is based on a two-step diazotization reaction, in which a cationic diazonium derivative of sulfanilamide is formed as intermediate before the final absorbing azo-product. We show that this …

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Inactivation Of [Fe-Fe]-Hydrogenase By O2. Thermodynamics And Frontier Molecular Orbitals Analyses, Daniela Dogaru, Stefan Motiu, Valentin Gogonea Mar 2009

Inactivation Of [Fe-Fe]-Hydrogenase By O2. Thermodynamics And Frontier Molecular Orbitals Analyses, Daniela Dogaru, Stefan Motiu, Valentin Gogonea

Chemistry Faculty Publications

The oxidation of H-cluster in gas phase, and in aqueous enzyme phase, has been investigated by means of quantum mechanics (QM) and combined quantum mechanics–molecular mechanics (QM/MM). Several potential reaction pathways (in the above-mentioned chemical environments) have been studied, wherein only the aqueous enzyme phase has been found to lead to an inhibited hydroxylated cluster. Specifically, the inhibitory process occurs at the distal iron (Fed) of the catalytic H-cluster (which isalso the atom involved in H2 synthesis). The processes involved in the H-cluster oxidative pathways are O2 binding, e− transfer, protonation, and H2O removal. We found that oxygen binding is …

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Isolation And Characterization Of Aromatase Inhibitors From Brassaiopsis Glomerulata (Araliaceae), Marcy J. Balunas, Bin Su, Soedarsono Riswan, Harry H.S. Fong, Robert W. Brueggemeier, John M. Pezzuto, A. Douglas Kinghorn Feb 2009

Isolation And Characterization Of Aromatase Inhibitors From Brassaiopsis Glomerulata (Araliaceae), Marcy J. Balunas, Bin Su, Soedarsono Riswan, Harry H.S. Fong, Robert W. Brueggemeier, John M. Pezzuto, A. Douglas Kinghorn

Chemistry Faculty Publications

The hexane- and ethyl acetate-soluble extracts of the leaves of Brassaiopsis glomerulata (Blume) Regel (Araliaceae), collected in Indonesia, were found to inhibit aromatase, the rate-limiting enzyme in the production of estrogens from androgens, in both enzyme- and cell-based aromatase inhibition (AI) assays. Bioassay-guided fractionation led to the isolation of six known compounds of the steroid and triterpenoid classes (1–6) from the hexane extract, of which 6β-hydroxystimasta-4-en-3-one (5), was moderately active in the cell-based AI assay. Fractionation of the ethyl acetate extract afforded seven pure isolates (7–13) of the modified peptide, fatty acid, monoterpenoid, and benzenoid types, including six known compounds …

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Synthesis And Evaluation Of Some Steroidal Oximes As Cytotoxic Agents: Structure/Activity Studies (I), Jianguo Cui, Lei Fan, Li Liang Huang, Hong Li Liu, Aimin Zhou Jan 2009

Synthesis And Evaluation Of Some Steroidal Oximes As Cytotoxic Agents: Structure/Activity Studies (I), Jianguo Cui, Lei Fan, Li Liang Huang, Hong Li Liu, Aimin Zhou

Chemistry Faculty Publications

The side chain of a compound plays an important role in its biological function. In our studies, we have found that hydroximinosteroid derivatives with different side chains and position of hydroximino on ring A and B displayed remarkable distinct cytotoxicities against a diversity of cancer cell types. Presence of an oxime group on ring B and a hydroxy on ring A or B resulted in a higher cytotoxicity than other structural motifs. In addition, a cholesterol-type side chain at position 17 was required for the biological activity. Our findings provide new evidence showing the relationship between the chemical structure and …

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Nos-Based Biopolymers: Towards Novel Thromboresistant No-Release Materials, Charbel Abou Diwan Jan 2009

Nos-Based Biopolymers: Towards Novel Thromboresistant No-Release Materials, Charbel Abou Diwan

ETD Archive

Nitric Oxide releasing biopolymers have the potential to prolong vascular graft and stent potency without adverse systemic vasodilation. It was reported in literature that eNOS-overexpressing endothelial cell seeding of synthetic small diameter vascular grafts decreased human platelet aggregation by 46 and bovine aortic smooth muscle cell proliferation by 67.2 in vitro. We hypothesized that incorporating the enzyme nitric oxide synthase (NOS) in biocompatible polymeric matrix will provide a source of NO that utilizes endogenous compounds to maintain an unlimited supply of NO. To test this hypothesis, we have incorporated the enzyme nitric oxide synthase into a polyethyleneimine film using a …

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Cofactor Control Of A Vital Enzymatic Reaction;The Effect Of Factor Va On Thrombin Formation During Blood Coagulation, Jamila Hirbawi Jan 2009

Cofactor Control Of A Vital Enzymatic Reaction;The Effect Of Factor Va On Thrombin Formation During Blood Coagulation, Jamila Hirbawi

ETD Archive

The LONG-TERM goal of our research is to study and analyze the structure and function of the factor V molecule in order to understand its regulatory effects on the natural process of hemostasis and its role in the life-threatening development of deep venous thrombosis. The SHORT-TERM goal of our research is to identify the amino acid residue(s) of factor V that interact with prothrombin during the assembly and function of the prothrombinase complex in order to fully understand its particular role in maintaining the integrity of the blood coagulation cascade. The final goal of the coagulation cascade is the formation …

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Hemoprotein-Mediated Activation Of Nitroalkanes, Ling Li Jan 2009

Hemoprotein-Mediated Activation Of Nitroalkanes, Ling Li

ETD Archive

Chemicals and drugs are known to be metabolized mostly by Cytochrome P450 xenobiotic metabolizing enzymes. However, the detailed mechanism of nitro-compounds metabolism is still unclear. The activation of nitro-xenobiotics by heme-P450 enzymes is a potential explanation for the origin of nitro-compound carcinogenesis. Investigating the interaction of simple nitro-compounds with redox activity of heme enzymes is therefore critical to explore the mechanism and products of activation. In this study, multiple analytical methods and instrumentations are employed and graphic and simulation software such as Origin┬« and Digisim┬« are utilized to quantitatively derive parameters from experimental raw data. This study shows that myoglobin, …

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Structural Investigation Of The Complex Of Filamin A Repeat 21 With Integrin Αiib And Β3 Cytoplasmic Tails – A Potential “Transmission” To Regulate Cell Migration, Jianmin Liu Jan 2009

Structural Investigation Of The Complex Of Filamin A Repeat 21 With Integrin Αiib And Β3 Cytoplasmic Tails – A Potential “Transmission” To Regulate Cell Migration, Jianmin Liu

ETD Archive

Cell functions in multi-cellular organisms are strongly depend on the dynamic cooperation between cell adhesion and cytoskeleton reorganization. Integrins, the major cell adhesion receptors, bind to extracellular matrix (ECM) and soluble ligands on the cell surface and link to the actin cytoskeleton inside the cell membrane. In this manner, integrins integrate cell adhesion and cytoskeleton reorganization by acting as a mechanical force transducer and a biochemical signaling hub (Zamir and Geiger 2001). Consequently, integrins are vital for development, immune responses, leukocyte traffic and hemostasis, and a variety of other cellular and physiological processes. Integrins are also are the focal point …

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Hemeproteins Bathed In Ionic Liquids;Examining The Role Of Water And Protons In Redox Behavior And Catalytic Function, John Joseph Moran Jan 2009

Hemeproteins Bathed In Ionic Liquids;Examining The Role Of Water And Protons In Redox Behavior And Catalytic Function, John Joseph Moran

ETD Archive

We investigate the changing behaviors of myoglobin and nitric oxide synthase (NOS) in the near-absence of bulk water and/or protons by using ionic liquid butyl methyl imidazolium tetrafluoroborate as a non-aqueous milieu. Through direct charge transfer and metalloprotein-mediated catalytic reduction of oxygen and nitric oxide, we shed light on diverging aspects on how the two hemeproteins face the scarcity of water and/or protons in bulk. Isotopic effect investigations using D2O further elucidates kinetic aspects of proton transfer. Finally, in the case of NOS oxygenase, pterin cofactor binding and NOS-mediated catalytic oxidation of L-arginine in ionic liquids interrogates proton and water …

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Development Of Quantitative Bioanalytical Methods For The Measurement Of Pharmaceutical Compounds Via Hplc-Uv And Hplc-Ms/Ms, Melissa A. Mcculloch Jan 2009

Development Of Quantitative Bioanalytical Methods For The Measurement Of Pharmaceutical Compounds Via Hplc-Uv And Hplc-Ms/Ms, Melissa A. Mcculloch

ETD Archive

Research in pharmaceutical treatments for illnesses and disease processes has rapidly grown in the past decade. The field is fueled by advances in our understanding of the molecular mechanics of the human body, coupled with the development of sophisticated scientific instruments which can efficiently generate massive amounts of important data. This has led to an ever-growing need for the development of quantitative bioanalytical methods to measure pharmaceutical compounds. In this work, the theory behind the analytical processes and instruments that make these investigations possible is discussed. Further, the development of two high performance liquid chromatographic (HPLC) methods with both ultra …

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Fabricating New Miniaturized Biosensors For The Detection Of Dna Damage And Dna Mismatches, N. Indika Perera Jan 2009

Fabricating New Miniaturized Biosensors For The Detection Of Dna Damage And Dna Mismatches, N. Indika Perera

ETD Archive

A large number of genetic diseases and genetic disorders are simply caused by base alterations in the genome. Therefore, developing efficient and cost effective techniques for routine detection of these alterations is of great importance. Different methods involving gel electrophoresis and Polymerase Chain Reaction have been widely employed, but majority of these methods are costly, time consuming, and lack throughput, creating a fundamental gap between the current state-of-the-art and desired characteristics of low-cost, high-speed, simplicity, versatility, and potential for miniaturization. In this study, we attempt to bridge this gap by developing new sensing platforms to detect DNA base mismatches and …

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New Generation Of Electrochemical Sensors For Nitric Oxide;Ruthenium/Carbon-Based Nanostructures And Colloids As Electrocatalytic Platforms, W. Pubudu M. Peiris Jan 2009

New Generation Of Electrochemical Sensors For Nitric Oxide;Ruthenium/Carbon-Based Nanostructures And Colloids As Electrocatalytic Platforms, W. Pubudu M. Peiris

ETD Archive

Nitric oxide (NO) is an important intercellular messenger that acts in many tissues to regulate a diverse range of physiological and pathological processes. The physiologically implications of NO function are far from being completely understood. The multifaceted reactivity of NO prompted the need for accurate determination of the concentration of this molecule. However, it is difficult to detect nitric oxide, particularly in biological media and near live cells due to its short half-life, a result of its reactivity and the low levels of NO produced in vivo. As a result, the accurate and reliable detection of NO under varying experimental …

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Nitric Oxide Synthase In Confined Environments;Detection And Quantification Of Nitric Oxide Released From Cells And Modified Liposomes Using A Sensitive Metal Catalyst-Pedot Modified Carbon Fiber Electrode, P. A. Reshani H. Perera Jan 2009

Nitric Oxide Synthase In Confined Environments;Detection And Quantification Of Nitric Oxide Released From Cells And Modified Liposomes Using A Sensitive Metal Catalyst-Pedot Modified Carbon Fiber Electrode, P. A. Reshani H. Perera

ETD Archive

Nitric oxide (NO) is a freely diffusible, gaseous free radical, associated with many physiological and pathological processes that include neuronal signaling, immune response, and inflammatory response. NO is produced from L-arginine in an NADPH-dependent reaction catalyzed by a family of nitric oxide synthase (NOS) enzymes. A deficiency in NO plays a role in hypertension, hyperglycaemia, and arteriosclerosis, among other pathological states. Conversely, increased NO levels contribute to arthritis, septic shock, and hypotention. Therefore, measuring and quantifying NO production in biological systems and matrices may be vital in elucidating physiological and pathological processes. The goal of this work is to develop …

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Development Of A Novel Gradient Chromatofocusing Tandem Mass Spectometry Technique For The Determination Of Cationic Compounds In Biofluids;Identification Of Caspace 3 Cleavage Sites Of Nhe-1 By High Performance Liquid Chromatography- Mass Spectrometry, Jianhua Tang Jan 2009

Development Of A Novel Gradient Chromatofocusing Tandem Mass Spectometry Technique For The Determination Of Cationic Compounds In Biofluids;Identification Of Caspace 3 Cleavage Sites Of Nhe-1 By High Performance Liquid Chromatography- Mass Spectrometry, Jianhua Tang

ETD Archive

In Part I, work was done to develop a novel gradient chromatofocusing liquid chromatography-tandem mass spectrometry (MS/MS) technique for the determination of ionic compounds in biological matrix. The analysis of ionic compounds poses a great challenge to current LC-MS techniques, due to the fact that there is little or no retention. These ionic compounds are eluted at almost the same time as biological matrix, which is normally directed to waste prior to connecting to the mass spectrometer. A review of current LC-MS techniques for ionic compounds is given in Chapter 1. They all have advantages and disadvantages. To retain and …

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Plasma Biomarkers For Age-Related Macular Degeneration, Jiaqian Ni Jan 2009

Plasma Biomarkers For Age-Related Macular Degeneration, Jiaqian Ni

ETD Archive

No abstract provided.

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Statins Induce Apoptosis In Ovarian Cancer Cells Through Activation Of Jnk And Enhancement Of Bim Expression, Hongli Liu, Shu Ling Liang, Sheetal Kumar, Crystal M. Weyman, Wendy Liu, Aimin Zhou Jan 2009

Statins Induce Apoptosis In Ovarian Cancer Cells Through Activation Of Jnk And Enhancement Of Bim Expression, Hongli Liu, Shu Ling Liang, Sheetal Kumar, Crystal M. Weyman, Wendy Liu, Aimin Zhou

Chemistry Faculty Publications

Purpose:Ovarian cancer is the leading cause of death among all gynecological malignancies in Western countries. Although therapy for ovarian cancer has been greatly improved in the past 20 years, the overall survival for patients with advanced ovarian cancer has not changed significantly. The poor survival rates in patients with advanced ovarian cancer are due both to late diagnosis and to lack of effective drugs for the majority of patients who have a relapse and develop resistance to current chemotherapy agents used for ovarian cancer. Thus, developing and discovering effective novel drugs with different molecular structures from conventional chemotherapy agents have …

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