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Articles 751 - 780 of 1129
Full-Text Articles in Chemistry
Classification And Energetics Of The Base-Phosphate Interactions In Rna, Craig L. Zirbel, Judit E. Šponer, Jiri Šponer, Jesse Stombaugh, Neocles B. Leontis
Classification And Energetics Of The Base-Phosphate Interactions In Rna, Craig L. Zirbel, Judit E. Šponer, Jiri Šponer, Jesse Stombaugh, Neocles B. Leontis
Chemistry Faculty Publications
Structured RNA molecules form complex 3D architectures stabilized by multiple interactions involving the nucleotide base, sugar and phosphate moieties. A significant percentage of the bases in structured RNA molecules in the Protein Data Bank (PDB) hydrogen-bond with phosphates of other nucleotides. By extracting and superimposing base-phosphate (BPh) interactions from a reduced-redundancy subset of 3D structures from the PDB, we identified recurrent phosphate-binding sites on the RNA bases. Quantum chemical calculations were carried out on model systems representing each BPh interaction. The calculations show that the centers of each cluster obtained from the structure superpositions correspond to energy minima on the …
Spiroadamantyl 1,2,4-Trioxolane, 1,2,4-Trioxane, And 1,2,4-Trioxepane Pairs: Relationship Between Peroxide Bond Iron(Ii) Reactivity, Heme Alkylation Efficiency, And Antimalarial Activity, Xiaofang Wang, Darren J. Creek, Yuxiang Dong, Jacques Chollet, Christian Scheurer, Sergio Wittlin, Susan A. Charman, Patrick H. Dussault, James K. Wood, Jonathan L. Vennerstrom
Spiroadamantyl 1,2,4-Trioxolane, 1,2,4-Trioxane, And 1,2,4-Trioxepane Pairs: Relationship Between Peroxide Bond Iron(Ii) Reactivity, Heme Alkylation Efficiency, And Antimalarial Activity, Xiaofang Wang, Darren J. Creek, Yuxiang Dong, Jacques Chollet, Christian Scheurer, Sergio Wittlin, Susan A. Charman, Patrick H. Dussault, James K. Wood, Jonathan L. Vennerstrom
Chemistry Faculty Publications
These data suggest that iron(II) reactivity for a set of homologous spiroadamantyl 1,2,4-trioxolane, 1,2,4-trioxane, and 1,2,4-trioxepane peroxide heterocycles is a necessary, but insufficient, property of animalarial peroxides. Heme alkylation efficiency appears to give a more accurate prediction of antimalarial activity than FeSO4-mediated reaction rates, suggesting that antimalarial activity is not merely dependent on peroxide bond cleavage, but also on the ability of reactive intermediates to alkylate heme or other proximal targets.
The Role Of Adenine In Fast Excited-State Deactivation Of Fad: A Femtosecond Mid-Ir Transient Absorption Study, Guifeng Li, Ksenija D. Glusac
The Role Of Adenine In Fast Excited-State Deactivation Of Fad: A Femtosecond Mid-Ir Transient Absorption Study, Guifeng Li, Ksenija D. Glusac
Chemistry Faculty Publications
We present a study of excited-state dynamics of two flavin cofactors: flavin-adenine dinucleotide (FAD) and flavin-mononucleotide (FMN). We used femtosecond mid-R transient absorption spectroscopy to study the effect of FAD conformation oil its excited-state behavior. The conformation of FAD was modulated by changing the solvent polarity: in D(2)O, FAD is present predominantly in the "stacked" conformation, in which flavin and adenine moieties are in close proximity to each other, whereas the increased amount of DMSO led to an increased amount of the "open" conformer. FMN served as a model system which lacks adenine. We found that the "stacked" conformer undergoes …
Probing Single-Molecule Interfacial Geminate Electron−Cation Recombination Dynamics, Yuanmin Wang, Xuefei Wang, H. Peter Lu
Probing Single-Molecule Interfacial Geminate Electron−Cation Recombination Dynamics, Yuanmin Wang, Xuefei Wang, H. Peter Lu
Chemistry Faculty Publications
Interfacial electron-cation recombination in zinc-tetra (4-carboxyphenyl) porphyrin (ZnTCPP)/TiO(2) nanoparticle system has been probed at the single-molecule level by recording and analyzing photon-to-photon pair times of the ZnTCPP fluorescence. We have. developed a novel approach to reveal the hidden single-molecule interfacial electron-cation recombination dynamics by analyzing the autocorrelation function and a proposed convoluted single-molecule interfacial electron-cation recombination model. Our results suggest that the fluctuations of the interfacial electron transfer (ET) reactivity modulate the ET cycles as well as the interfacial electron-cation recombination dynamics. On the basis of this model, the single-molecule electron-cation recombination time of ZnTCPP/-TiO(2) system is deduced to be …
Fluorenylidene−Pyrroline Biomimetic Light-Driven Molecular Switches, Laura Rivado-Casas, Diego Sampedro, Pedro J. Campos, Stefania Fusi, Vinicio Zanirato, Massimo Olivucci
Fluorenylidene−Pyrroline Biomimetic Light-Driven Molecular Switches, Laura Rivado-Casas, Diego Sampedro, Pedro J. Campos, Stefania Fusi, Vinicio Zanirato, Massimo Olivucci
Chemistry Faculty Publications
A new family of biomimetic photoactivated molecular switches based in the retinal chromophore is described. Expedient synthesis allows a library of compounds with a different substitution pattern, including chiral substituents, to be obtained. The effect of substitution, solvent, and light source on the photoisomerization step has been assessed. The absorption maximum has been red-shifted ca. 50 nm with respect to related systems and rotation is now easily achieved by using visible light.
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
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. …
Phenylbenzimidazole-Based New Bipolar Host Materials For Efficient Phosphorescent Organic Light-Emitting Diodes, Shin-Ya Takizawa, Victor A. Montes, Pavel Anzenbacher Jr.
Phenylbenzimidazole-Based New Bipolar Host Materials For Efficient Phosphorescent Organic Light-Emitting Diodes, Shin-Ya Takizawa, Victor A. Montes, Pavel Anzenbacher Jr.
Chemistry Faculty Publications
Two new bipolar host materials based on a 1,3,5-tris(N-phenylbenzimidazol-2-yl)benzene (TPBI) core with the carbazole and diphenylamine groups were designed, synthesized, and applied in phosphorescent organic light-emitting diodes (PhOLEDs). The DFT calculations indicated desirable distribution of HOMO and LUMO densities, suggesting potential for bipolar charge transport. In addition, the electrochemical and phosphorescence studies revealed that neither the LUMO level nor the triplet energies differ significantly from the parent TPBI suggesting that the new materials would be suitable as hosts capable of both electron and hole transport and suitable for harvesting green electrophosphorescence. As a result of broader charge recombination …
Biocatalytic Synthesis Of Diethanolamide Surfactants Under Mild Reaction Conditions, Galilee Uy Semblante, Modesto Tan Chua, Soma Chakraborty
Biocatalytic Synthesis Of Diethanolamide Surfactants Under Mild Reaction Conditions, Galilee Uy Semblante, Modesto Tan Chua, Soma Chakraborty
Chemistry Faculty Publications
Synthesis of fatty acid diethanolamide was carried out by the condensation of diethanolamine with lauric acid, decanoic acid and octanoic acid in the presence of Novozym 435. The influence of solvent, time, temperature and agitation on the reaction rate was studied. Formation of lauroyl diethanolamide was complete in 6h in acetonitrile at 50° C whereas in toluene the reaction was not complete in 6h. Increase of reaction temperature from 50° C to 70° C increased the reaction rate. Proper agitation of the reaction mixture enhanced the reaction rate. Reaction in solution appeared to be more efficient than the reaction in …
Evaluation Of Silica Sol-Gel Microcapsule For The Controlled Release Of Insect Repellent, N,N-Diethyl-2-Methoxybenzamide, On Cotton, Ann Shireen Chan, Judy Del Valle, Kendricks Lao, Christian Malapit, Modesto Tan Chua, Regina C. So
Evaluation Of Silica Sol-Gel Microcapsule For The Controlled Release Of Insect Repellent, N,N-Diethyl-2-Methoxybenzamide, On Cotton, Ann Shireen Chan, Judy Del Valle, Kendricks Lao, Christian Malapit, Modesto Tan Chua, Regina C. So
Chemistry Faculty Publications
N,N-diethyl-2-methoxybenzamide, an insect repellent compound, was incorporated into cotton textile using the sol-gel method. Evaluation of the results of four different sol-gel formulations showed that a lower condensation rate resulted in significantly better encapsulation. Also investigated was the encapsulation in the presence of other polymers like polymethylmethacrylate (PMMA), polystyrene (PS) and polyvinyl alcohol (PVA) that prolong the release of the repellent. The sol-gel formulation, SiO2 : polymethylmethacrylate (PMMA) (1:0.8), gave smooth fabric and good encapsulation of the insect repellent compound. PS and PVA resulted in cloths which are aesthetically undesirable. Cloths coated with sol-gel PVA gave the best repellent release …
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
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 …
Electronic Properties Of 4-Substituted Naphthalimides, Pavel Kucheryavy, Guifeng Li, Shubham Vyas, Christopher Hadad, Ksenija D. Glusac
Electronic Properties Of 4-Substituted Naphthalimides, Pavel Kucheryavy, Guifeng Li, Shubham Vyas, Christopher Hadad, Ksenija D. Glusac
Chemistry Faculty Publications
This paper describes a study of excited-state properties of naphthalmide (NI) and four 4-substituted derivatives: 4-chloronaphthalimide (Cl-NI), 4-methylthionaphthalmide (MeS-NI), 4-nitronaphthalimide (O(2)N-NI), and 4-(N,N-dimethylaminonaphthalimide (Me(2)N-NI). Steady-state absorption and fluorescence spectra were collected in solvents of varying polarity to determine the excited-state character of NI derivatives. Furthermore. the excited-state dynamics were studied Using femtosecond transient absorption spectroscopy. The experimental findings were compared to calculated data obtained using time-dependent density functional (TD-DFT) methods. We found that light absorption by all NI derivatives leads to the production of the second excited state (S(2)), which was found to have a n,pi* character. Within similar to …
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
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 …
Frequency And Isostericity Of Rna Base Pairs, Craig L. Zirbel, Jesse Stombaugh, Eric Westhof
Frequency And Isostericity Of Rna Base Pairs, Craig L. Zirbel, Jesse Stombaugh, Eric Westhof
Chemistry Faculty Publications
Most of the hairpin, internal and junction loops that appear single-stranded in standard RNA secondary structures form recurrent 3D motifs, where non-WatsonCrick base pairs play a central role. Non-WatsonCrick base pairs also play crucial roles in tertiary contacts in structured RNA molecules. We previously classified RNA base pairs geometrically so as to group together those base pairs that are structurally similar (isosteric) and therefore able to substitute for each other by mutation without disrupting the 3D structure. Here, we introduce a quantitative measure of base pair isostericity, the IsoDiscrepancy Index (IDI), to more accurately determine which base pair substitutions can …
Inactivation Of [Fe-Fe]-Hydrogenase By O2. Thermodynamics And Frontier Molecular Orbitals Analyses, Daniela Dogaru, Stefan Motiu, Valentin Gogonea
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 …
Polyelectrolyte-Linked Film Assemblies Of Nanoparticles And Nanoshells: Growth, Stability, And Optical Properties, Anne A. Galyean, Justin Malinowski, Robert W. Day, Kevin W. Kittredge, Michael C. Leopold
Polyelectrolyte-Linked Film Assemblies Of Nanoparticles And Nanoshells: Growth, Stability, And Optical Properties, Anne A. Galyean, Justin Malinowski, Robert W. Day, Kevin W. Kittredge, Michael C. Leopold
Chemistry Faculty Publications
Multi-layer films of nanoparticles and nanoshells featuring various polymeric linkage molecules have been assembled and their optical properties characterized. The growth dynamics, including molecular weight effects, and stability of the various nanoparticle film constructions, using both single polymer as well as combinations of alternating charge polyelectrolytes as linking mechanisms, are presented. The polymeric linkers studied include poly-L-lysine, poly-L-arginine, poly(allylamine hydrochloride), and polyamidoamine dendrimers. Significantly air stable films were achieved with the use of multi-layered polymeric bridges between the nanoparticles and nanoshells. Optical sensitivity normally observed with these nanomaterials in solution was observed for their corresponding film geometries, with the nanoshell …
Trimethylsilyl Trifluoromethanesulfonate- Accelerated Addition Of Catalytically Generated Zinc Acetylides To Aldehydes, C. Wade Downey, Brian D. Mahoney, Vincent R. Lipari
Trimethylsilyl Trifluoromethanesulfonate- Accelerated Addition Of Catalytically Generated Zinc Acetylides To Aldehydes, C. Wade Downey, Brian D. Mahoney, Vincent R. Lipari
Chemistry Faculty Publications
In the presence of TMSOTf, a wide variety of terminal acetylenes add rapidly and efficiently to aldehydes via a catalytically generated zinc acetylide. In the absence of TMSOTf, no reaction is observed under otherwise identical conditions.
Beta-Peptides With Improved Affinity For Hdm2 And Hdmx, Elizabeth A. Harker, Douglas S. Daniels, Danielle A. Guarracino, Alanna S. Schepartz
Beta-Peptides With Improved Affinity For Hdm2 And Hdmx, Elizabeth A. Harker, Douglas S. Daniels, Danielle A. Guarracino, Alanna S. Schepartz
Chemistry Faculty Publications
We previously described a series of 314-helical β-peptides that bind the hDM2 protein and inhibit its interaction with a p53-derived peptide in vitro. Here we present a detailed characterization of the interaction of these peptides with hDM2 and report two new β-peptides in which non-natural side chains have been substituted into the hDM2-recognition epitope. These peptides feature both improved affinity and inhibitory potency in fluorescence polarization and ELISA assays. Additionally, one of the new β-peptides also binds the hDM2-related protein, hDMX, which has been identified as another key therapeutic target for activation of the p53 pathway in tumors.
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
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 …
Ultrafast Energy Transfer In Oligofluorene−Aluminum Bis(8-Hydroxyquinoline)Acetylacetone Coordination Polymers, Victor A. Montes, Grigory V. Zyryanov, Evgeny Danilov, Neeraj Agarwal, Manuel A. Palacios, Pavel Anzenbacher Jr.
Ultrafast Energy Transfer In Oligofluorene−Aluminum Bis(8-Hydroxyquinoline)Acetylacetone Coordination Polymers, Victor A. Montes, Grigory V. Zyryanov, Evgeny Danilov, Neeraj Agarwal, Manuel A. Palacios, Pavel Anzenbacher Jr.
Chemistry Faculty Publications
Understanding the excited-state dynamics in conjugated systems can lead to their better utilization in optical sensors, organic photovoltaics (OPVs), and organic light-emitting diodes (OLEDs). We present the synthesis of self-assembled coordination polymers comprising two types of fluorescent moieties: discrete fluorene oligomers of a well-defined length (n = 1-9) connected via aluminum(III) bis(8-quinolinolate)acetylacetone joints. Due to their well-defined structure, these materials allowed for a detailed study of energy migration processes within the materials. Thus, femtosecond transient spectroscopy was used to study the ultrafast energy transfer from the oligofluorene to the quinolinolate moieties, which was found to proceed at a rate …
Probing Single-Molecule Interfacial Electron Transfer Dynamics Of Porphyrin On Tio2 Nanoparticles, Yuanmin Wang, Xuefei Wang, Sujit Kumar Ghosh, H. Peter Lu
Probing Single-Molecule Interfacial Electron Transfer Dynamics Of Porphyrin On Tio2 Nanoparticles, Yuanmin Wang, Xuefei Wang, Sujit Kumar Ghosh, H. Peter Lu
Chemistry Faculty Publications
Single-molecule interfacial electron transfer (ET) dynamics has been studied by using single-molecule fluorescence spectroscopy and microscopic imaging. For a single-molecule zinc-tetra (4-carboxyphenyl) porphyrin (ZnTCPP)/TiO2 nanoparticle system, the single-molecule fluorescence trajectories show strong fluctuation and blinking between bright and dark states. The intermittency and fluctuation of the single-molecule fluorescence are attributed to the variation of the reactivity of interfacial electron transfer. The nonexponential autocorrelation function and the power-law distribution of the probability density of dark times imply the dynamic and static inhomogeneities of the interfacial ET dynamics. On the basis of the power-law analysis, the variation of single-molecule interfacial ET reactivity …
Radiative Recombination Of Spatially Extended Excitons In (Znse/Cds)/Cds Heterostructured Nanorods, Nishshanka N. Hewa-Kasakarage, Maria Kirsanova, Alexander Nemchinov, Nickolas Schmall, Patrick Z. El-Khoury, Alexander N. Tarnovsky, Mikhail Zamkov
Radiative Recombination Of Spatially Extended Excitons In (Znse/Cds)/Cds Heterostructured Nanorods, Nishshanka N. Hewa-Kasakarage, Maria Kirsanova, Alexander Nemchinov, Nickolas Schmall, Patrick Z. El-Khoury, Alexander N. Tarnovsky, Mikhail Zamkov
Chemistry Faculty Publications
We report on organometallic synthesis of luminescent (ZnSe/CdS)/CdS semiconductor heterostructured nanorods (hetero-NRs) that produce an efficient spatial separation of carriers along the main axis of the structure (type II carrier localization). Nanorods were fabricated using a seeded-type approach by nucleating the growth of 20-100 nm CdS extensions at [000 +/- 1] facets of wurtzite ZnSe/CdS core/shell nanocrystals. The difference in growth rates of CdS in each of the two directions ensures that the position of ZnSe/CdS seeds in the final structure is offset from the center of hetero-NRs, resulting in a spatially asymmetric distribution of carrier wave functions along the …
Anion Binding Modes In Meso-Substituted Hexapyrrolic Calix[4]Pyrrole Isomers, Kai-Chi Chang, Tsuyoshi Minami, Petr Koutnik, Pavel Y. Savechenkov, Yuanli Liu, Pavel Anzenbacher Jr.
Anion Binding Modes In Meso-Substituted Hexapyrrolic Calix[4]Pyrrole Isomers, Kai-Chi Chang, Tsuyoshi Minami, Petr Koutnik, Pavel Y. Savechenkov, Yuanli Liu, Pavel Anzenbacher Jr.
Chemistry Faculty Publications
We report on the synthesis of a new receptor for anions, meso-substituted hexapyrrolic calix[4]pyrrole 1. The calix[4]pyrrole's core features two additional pyrrole side-arms suspended above or below the calix[4]pyrrole core. This hexapyrrolic calix[4]pyrrole 1 is formed as cis- and trans-configurational isomers, the structures of which have been determined by single crystal X-ray diffraction. The anion binding experiments revealed interesting difference in the binding mode: The cis-1 isomer binds anions in a mixed binding mode featuring a combination of hydrogen bonding and anion-pi interactions resulting in an unexpected strong binding. On the other hand, the trans-1 isomer displays only hydrogen bonding …
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
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 …
Stain Etching With Fe(Iii), V(V), And Ce(Iv) To Form Microporous Silicon, M E. Dudley, Kurt Kolasinski
Stain Etching With Fe(Iii), V(V), And Ce(Iv) To Form Microporous Silicon, M E. Dudley, Kurt Kolasinski
Chemistry Faculty Publications
Stain etchants made from (HF+V(2)O(5)) or (HF+FeCl(3)center dot 6H(2)O+HCl or H(2)SO(4)) exhibited virtually no initiation time before the formation of porous silicon. Etching with Fe(III) solutions for extended periods resulted in a unique dual layer structure that can reach a thickness >10 mu m and exhibited not only red-orange but also green photoluminescence (PL). Etching with (CeF(4)+H(2)SO(4)) produced extremely uniform films. Visible PL was observed immediately after etching except for those films produced with (CeF(4)+H(2)SO(4)), which required several days of air exposure before bright and robust PL developed.
Etching Of Silicon In Fluoride Solutions, Kurt W. Kolasinski
Etching Of Silicon In Fluoride Solutions, Kurt W. Kolasinski
Chemistry Faculty Publications
No abstract provided.
Sustainability: Energy & Global Chemistry, Kurt W. Kolasinski
Sustainability: Energy & Global Chemistry, Kurt W. Kolasinski
Chemistry Faculty Publications
No abstract provided.
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
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 …
The Effect Of Dielectric Friction On The Rate Of Charge Separation In Type Ii Znse/Cds Semiconductor Nanorods, Alexander N. Tarnovsky, Nishshanka N. Hewa-Kasakarage, Patrick Z. El-Khoury, Nickolas Schmall, Maria Kirsanova, Alexander Nemchinov, Alexey Bezryadin, Mikhail Zamkov
The Effect Of Dielectric Friction On The Rate Of Charge Separation In Type Ii Znse/Cds Semiconductor Nanorods, Alexander N. Tarnovsky, Nishshanka N. Hewa-Kasakarage, Patrick Z. El-Khoury, Nickolas Schmall, Maria Kirsanova, Alexander Nemchinov, Alexey Bezryadin, Mikhail Zamkov
Chemistry Faculty Publications
The effect of dielectric friction on the rate of charge separation in type II ZnSe/CdS semiconductor nanorods has been investigated using picosecond transient absorption spectroscopy. The spatial separation of an excited electron-hole pair was estimated from the redshift in band edge absorption corresponding to the decrease in the exciton binding energy. The present study identifies a considerable effect of the solvent polarity on the rate of charge separation in semiconductor heterostructures, which should be taken into account when selecting nanorod caging media, such as solvents or polymer matrices. © 2009 American Institute of Physics.
Design Of Novel Anticancer Drugs Utilizing Busulfan For Optimizing Pharmacological Properties And Pattern Recognition Techniques For Elucidation Of Clinical Efficacy, Ronald Bartzatt
Chemistry Faculty Publications
Chronic myelogenous leukemia (CML) is a disorder in which an excessive number of blood stem cells develop into the white blood cell group called granulocytes. The anticancer drug Busulfan is a cell cycle non-specific alkylating agent which is utilized to maintain white blood cell counts below 15000 cells/microliter. The side effects induced by busulfan are significant and affirms the intimation for new drug constructs. Fifteen analogous compounds were generated from the molecular structure of busulfan . These compounds retain the double methanesulfonate functional groups descriptive of this class of alkylating anticancer drugs. However, the carbon chain substituent separating the methanesulfonate …
Preparation And Characterization Of Some Substituted Benzyl N-Nitrosocarbamates Containing An N-2-(Methylthio)Ethyl Or A Bis(2-Aminoethyl)Sulfide Functionality, Satya Venkata, Eric Shamo, Vladimir Benin
Preparation And Characterization Of Some Substituted Benzyl N-Nitrosocarbamates Containing An N-2-(Methylthio)Ethyl Or A Bis(2-Aminoethyl)Sulfide Functionality, Satya Venkata, Eric Shamo, Vladimir Benin
Chemistry Faculty Publications
The synthesis and characterization of some substituted benzyl N-nitrosocarbamates with an N-2-(methylthio)ethyl or a bis(2-aminoethyl)sulfide functionality is reported, as a part of a long-term goal to design and prepare novel photolabile structures that could be used as substances for controlled release of alkylating and/or crosslinking agents. The synthesis was accomplished by reaction of benzyl chloroformates with the corresponding amines, resulting in the preparation of carbamates. The latter were subsequently nitrosated, utilizing two different N-nitrosation methods, to yield the target structures.