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Full-Text Articles in Medicinal-Pharmaceutical Chemistry

Mesoporous Silica Nanomaterials And Magnetic Nanoparticles Based Stimuli-Responsive Controlled-Release Delivery Systems, Supratim Giri Jan 2008

Mesoporous Silica Nanomaterials And Magnetic Nanoparticles Based Stimuli-Responsive Controlled-Release Delivery Systems, Supratim Giri

Retrospective Theses and Dissertations

The research presented and discussed within this dissertation involves the development of mesoporous silica nanomaterials and magnetic nanoparticles based stimuli-responsive controlled-release delivery systems.;A superparamagnetic iron oxide nanoparticle-capped, MCM-41 type mesoporous silica nanorod-based controlled-release delivery system (Magnet-MSN) was synthesized. The stimuli-responsive release profiles of fluorescein-loaded Magnet-MSN delivery systems in the presence of external magnetic field was studied by using cell-produced antioxidants as triggers for releasing fluorescein molecules. The intracellular delivery efficiency of the Magnet-MSN system with human cervical cancer cells (HeLa) in vitro was demonstrated involving fluorescein molecules as model drug.;To take the advantage of the intracellular delivery capability ...


Synthesis Of Natural Compounds In Echinacea , Jaehoon Bae Jan 2006

Synthesis Of Natural Compounds In Echinacea , Jaehoon Bae

Retrospective Theses and Dissertations

In this dissertation, we have investigated the direct and efficient synthetic route to biologically active natural products. Chapter 1 describes the synthesis of some of the natural compounds in Echinacea. Several main constituents of the plant Echinacea have been synthesized for the first time. We have developed a direct and flexible route to amides and ketones in Echinacea. The synthesized natural products have been used for standard samples for the biological studies. Chapter 2 describes the new tandem strategy to construct bicyclic systems by a Diels-Alder/ene reaction and its application for the synthesis of Isoligularone. During this tandem reaction ...


Enantiomeric Chromatographic Separations And Ionic Liquids , Jie Ding Jan 2005

Enantiomeric Chromatographic Separations And Ionic Liquids , Jie Ding

Retrospective Theses and Dissertations

The chiral nature of compounds contributes to their bioactivity and their various pharmaceutical/industrial uses. As a result, the Food and Drug Administration (FDA) has implemented policies for analyzing the enantiomers of chiral compounds. Gas chromatography (GC) and liquid chromatography (LC) utilizing chiral stationary phases are the two most commonly used methods to achieve direct enantiomeric separations of chiral compounds. The first part of this dissertation includes a review of direct separation of enantiomers in gas and liquid chromatography, an example of the enantiomeric separation of various racemic sulfoxides and sulfinate esters on four derivatized cyclodextrin chiral stationary phases using ...


New Palladium-Catalyzed Approaches To Heterocycles And Carbocycles, Qinhua Huang Jan 2004

New Palladium-Catalyzed Approaches To Heterocycles And Carbocycles, Qinhua Huang

Retrospective Theses and Dissertations

The tert-butylimines of o-(1-alkynyl)benzaldehydes and analogous pyridinecarbaldehydes have been cyclized under very mild reaction conditions in the presence of I2, ICl, PhSeCl, PhSCl and p-O2NC6H4SCl to give the corresponding halogen-, selenium- and sulfur-containing disubstituted isoquinolines and naphthyridines, respectively. Monosubstituted isoquinolines and naphthyridines have been synthesized by the metal-catalyzed ring closure of these same iminoalkynes. This methodology accommodates a variety of iminoalkynes and affords the anticipated heterocycles in moderate to excellent yields.;The Pd(II)-catalyzed cyclization of 2-(1-alkynyl)arylaldimines in the presence of various alkenes provides an efficient way to synthesize a variety of 4-(1-alkenyl)-3-arylisoquinolines ...


Synthesis Of Polycyclic Natural Products , Tuan Hoang Nguyen Jan 2003

Synthesis Of Polycyclic Natural Products , Tuan Hoang Nguyen

Retrospective Theses and Dissertations

Highly oxidized polycyclic natural products are abundant in nature and have diverse biological activities. Hyperforin has been identified as the sole constituent responsible for the antidepressant characteristic of St. John's wort. An approach to an oxidized bicyclic phloroglucin core of hyperforin is described. Puupehenone, a sesquiterpene found in marine sponges, has recently emerged as a strong candidate to treat tuberculosis. The synthesis of the BCD rings of puupehenone containing a quinone methide moiety is described.


New Methods For The Synthesis Of Natural Products , Alexey G. Melekhov Jan 1999

New Methods For The Synthesis Of Natural Products , Alexey G. Melekhov

Retrospective Theses and Dissertations

In this work we developed new approaches to three different classes of compounds. In the first chapter we employed PIFA as an oxidant to develop a direct route to pyrrolobenzodiazepines. We also developed a new way to generate acyl radicals by oxidative decarboxylation. The utility of this methodology was shown in the synthesis of 8-deoxy DC-81. In the second chapter we developed a five-step synthetic route to 1,4-phenanthrenequinones. We also used one of these phenanthrenequinones for the construction of an angularly-fused aromatic systems. In the third chapter we studied Lewis acid-mediated cyclizations of acyl quinones. We synthesized a precursor ...


Combination Of Capillary Isoelectric Focusing And Liquid Chromatography With Electrospray Ionization Mass Spectrometry For Protein Characterization , Jing Wei Jan 1998

Combination Of Capillary Isoelectric Focusing And Liquid Chromatography With Electrospray Ionization Mass Spectrometry For Protein Characterization , Jing Wei

Retrospective Theses and Dissertations

Combination of capillary isoelectric focusing (CIEF) and liquid chromatography (LC) with electrospray ionization mass spectrometry (ESIMS) is utilized for protein characterization;Both CIEF-ESIMS and LC-MS are studied for phosphoprotein characterization. At the intact protein level, on-line CTEF-ESIMS is applied for phosphorylation analysis to obtain the two dimensional information: isoelectric point and molecular mass. At the peptide level, on-line LC-ESI-MS and LC-ESI neutral loss MS/MS were highly specific for the determination of sites of phosphorylation and successfully applied on the tryptic digest of tau proteins phosphorylated by different kinases;On-line combination of CIEF with ESI-TOF MS is demonstrated for high ...


Capillary Electrophoresis Separation Of Neutral Organic Compounds, Pharmaceutical Drugs, Proteins And Peptides, Enantiomers And Anions , Wei-Liang Ding Jan 1998

Capillary Electrophoresis Separation Of Neutral Organic Compounds, Pharmaceutical Drugs, Proteins And Peptides, Enantiomers And Anions , Wei-Liang Ding

Retrospective Theses and Dissertations

Addition of a novel anionic surfactant, namely lauryl polyoxyethylene sulfate, to an aqueous-acetonitrile electrolyte makes it possible to separate nonionic organic compounds by capillary electrophoresis. Separation is based on differences in the association between analytes and the surfactant. Highly hydrophobic compounds such as polyaromatic hydrocarbons are well separated by this new surfactant. Migration times of analytes can be readily changed over an unusually large range by varying the additive concentration and the proportion of acetonitrile in the electrolyte. Several examples are given, including the separation of four methylbenz (a) anthracene isomers and the separation of normal and deuterated acetophenone;The ...


Novel Materials And Methods For Solid-Phase Extraction And High-Performance Liquid Chromatography , Dianna Lynn Ambrose Jan 1997

Novel Materials And Methods For Solid-Phase Extraction And High-Performance Liquid Chromatography , Dianna Lynn Ambrose

Retrospective Theses and Dissertations

Solid-phase extraction (SPE) is one of the most popular sample preparation techniques for the isolation and preconcentration of organic compounds from aqueous samples. Modified porous polystyrene-divinylbenzene (PS-DVB) resins containing polar groups are superior for SPE of organic solutes from aqueous samples. These modified resins display excellent surface hydrophilicity and improved extraction efficiencies. Silicalite is a hydrophobic molecular sieve with an unusual crystal structure. Because of its unique structure, Silicalite adsorbs organic analytes from aqueous samples due to hydrophobic interactions;The ability of Silicalite and a lightly sulfonated PS-DVB resin to extract various organic test compounds from aqueous samples was compared ...


Electrochemically-Modulated Liquid Chromatography (Emlc): Column Design, Retention Processes, And Applications , En-Yi Ting Jan 1997

Electrochemically-Modulated Liquid Chromatography (Emlc): Column Design, Retention Processes, And Applications , En-Yi Ting

Retrospective Theses and Dissertations

This dissertation explores a new separation technique, electrochemically modulated liquid chromatography (EMLC), from the column design, retention processes, to the pharmaceutical applications. A literature review, general summary, and perspectives of this technique are also described. Chapter 1 presents the newly designed EMLC column. The principal modification of this design is to connect the porous stainless steel column as counter electrode as opposed to part of working electrode in the previous design. The improvement in performance from this modification results in a shorter response time to changes in applied potential (E appl) and a better control of E appl at cathodic ...


Total Synthesis Of Angularly Fused Natural Products , Guohua Zhao Jan 1996

Total Synthesis Of Angularly Fused Natural Products , Guohua Zhao

Retrospective Theses and Dissertations

The synthesis of angularly fused quinone natural product G-2N has been achieved using a photoenolization reaction and a Diels-Alder reaction in the key carbon-carbon bond forming steps. This route is direct and flexible. It should be applicable to synthesis of other analogous natural products;The skeleton of colchicine has been achieved using a Diels-Alder reaction followed by an electrophilic addition to the A ring as key steps. Our synthetic approach is direct. It could provide an efficient entry to total synthesis of colchicine.


Synthesis Of Diterpene Alkaloids , Tiberiu Mircea Siclovan Jan 1996

Synthesis Of Diterpene Alkaloids , Tiberiu Mircea Siclovan

Retrospective Theses and Dissertations

Aconitine, atisine and garrya type diterpene alkaloids show remarkable biological activity and have a number of structural features in common. Due to their complex structure, there is a discrepancy between progress made lately in the identification, isolation and characterization of new members of this family, on one hand, and successful efforts towards their total synthesis, on the other;Our synthetic studies led us to develop a highly reproducible synthesis of adamantane-containing compounds via the corresponding bridgehead anions;Studies on the application of functionalized bridgehead radicals in natural product synthesis resulted in the development of a versatile, mild and highly tolerant ...


Synthetic Approaches To Huperzine A , Danette René Vines Jan 1994

Synthetic Approaches To Huperzine A , Danette René Vines

Retrospective Theses and Dissertations

The natural product huperzine A has been found to possess activity as a nootropic agent. Because of its memory facilitating effects, huperzine A represents a promising drug for the treatment of neurodegenerative diseases, such as Alzheimer's disease. As life expectancy increases, identifying and synthesizing drugs which treat cognitive dysfunction becomes a primary health objective;This study was undertaken to synthesize huperzine A, and to offer a direct route to improved analogs of huperzine A. A bicyclic amino ketone for the synthesis of huperzine A was prepared in six steps. The conjugate addition of metallated alkylpyridines afforded a direct route ...


Synthesis, Structure Features And Application Of Pro-Azaphsphatranes As Catalysts And Strong Non-Ionic Bases In Organic Synthesis , Jiansheng Tang Jan 1994

Synthesis, Structure Features And Application Of Pro-Azaphsphatranes As Catalysts And Strong Non-Ionic Bases In Organic Synthesis , Jiansheng Tang

Retrospective Theses and Dissertations

This dissertation describes the development of pro-azaphosphatranes ZP(MeNCH[subscript]2CH[subscript]2)[subscript]3N as versatile useful materials in organic synthesis;Pro-imidophosphatranes MeN= P(MeNCH[subscript]2CH[subscript]2)[subscript]3N and PhN= P(MeNCH[subscript]2CH[subscript]2)[subscript]3N, their corresponding acyclic analogues MeN= P(NMe[subscript]2)[subscript]3 and PhN= P(NMe[subscript]2)[subscript]3, and their conjugate acids as well as the conjugate acid of the commercially available non-ionic base P[subscript]4-t-Bu (i.e. t-BuN=P (N=P(NMe[subscript]2)[subscript]3][subscript]3) have been synthesized. Equilibria measured by [superscript ...


Development Of An Ocular Drug Release System For Cattle , Thomas Quang Dinh Jan 1991

Development Of An Ocular Drug Release System For Cattle , Thomas Quang Dinh

Retrospective Theses and Dissertations

An erodible ring-shaped ocular insert containing an antibiotic (tylosin tartrate) has been developed for treatment of infectious bovine keratoconjunctivitis (IBK). Four additional tasks have been completed: (1) a test to determine the retention time of the ocular device in the eyes of the calves, (2) an in vitro test to determine the degradation characteristics of the device, (3) an in vitro study to obtain the drug release profiles of the insert, and (4) a study to compare the use of rings and a field treatment method using infected cattle;The device remained in the eyes an average of 3.92 ...


Synthetic Dibenzofurans Structurally Related To Known Analgesics, Frederick Albert Yeoman Jan 1944

Synthetic Dibenzofurans Structurally Related To Known Analgesics, Frederick Albert Yeoman

Retrospective Theses and Dissertations

No abstract provided.


Some Correlations Between Hypnotic Action And Chemical Constitution , William Glen Bywater Jan 1934

Some Correlations Between Hypnotic Action And Chemical Constitution , William Glen Bywater

Retrospective Theses and Dissertations

A review of theories of narcosis has been made, and some correlations between constitution and activity have been presented for the aliphatic hypnotics;The close and important relationship of dibenzofuran and its derivatives to morphine has been discussed. The following derivatives to morphine has been discussed. The following derivatives to morphine has been discussed. The following derivatives of dibenzofuran haven been prepared for use in physiological tests: 2-, 3-, and 4-amino-, 2- and 3-hydroxy-dibenzofuran, and 2- and 3-dibenzofurancarboxylic acids;A necessary study of nuclear substitution in dibenzofuran has been made prior to the preparation of derivatives for physiological tests. It ...