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- Title
- Synthesis and characterization of group IVB metallocene materials derived from hematoporphyrin IX.
- Creator
- Rivalta, Alberto Enrico., Florida Atlantic University, Carraher, Charles E., Haky, Jerome E.
- Abstract/Description
-
New organometallic containing materials were synthesized by the reaction of Group IVB metallocene dichlorides of the form Cp2MCl2 where M = Ti, Ar, and Hf with Hematoporphyrin IX using the interfacial condensation polymerization technique. The structural characterization was accomplished using infrared and mass spectroscopy and elemental analysis. The results obtained from these techniques showed the presence of the metal ester and ether bonding as evidence that the reaction occurred. The...
Show moreNew organometallic containing materials were synthesized by the reaction of Group IVB metallocene dichlorides of the form Cp2MCl2 where M = Ti, Ar, and Hf with Hematoporphyrin IX using the interfacial condensation polymerization technique. The structural characterization was accomplished using infrared and mass spectroscopy and elemental analysis. The results obtained from these techniques showed the presence of the metal ester and ether bonding as evidence that the reaction occurred. The product derived from titanocene dichloride, 12-A, exhibited growth inhibition characteristics towards the Candid albicans and Staphylococcus aureus microorganisms. From the preliminary metal adsorption studies it was shown that this product also bound nickel ions.
Show less - Date Issued
- 1993
- PURL
- http://purl.flvc.org/fcla/dt/14940
- Subject Headings
- Organometallic chemistry, Porphyrins, Hematoporphyrin, Metallocenes
- Format
- Document (PDF)
- Title
- Computer simulation for the optimization of reverse osmosis seawater desalination pretreatment.
- Creator
- Corlay, Brieuc., Florida Atlantic University, Haky, Jerome E.
- Abstract/Description
-
A computer program was developed to simulate and optimize the chemical pretreatment of seawater prior to desalination by reverse osmosis. The model was created using LabViewRTM programming language. The automation of the process was achieved using a PID (proportional, integrative, derivative) controller. The effects of a variety of operating conditions were modeled to optimize the chemical pretreatment. We focused on three parameters: hardness removal, iron removal and control of biogrowth....
Show moreA computer program was developed to simulate and optimize the chemical pretreatment of seawater prior to desalination by reverse osmosis. The model was created using LabViewRTM programming language. The automation of the process was achieved using a PID (proportional, integrative, derivative) controller. The effects of a variety of operating conditions were modeled to optimize the chemical pretreatment. We focused on three parameters: hardness removal, iron removal and control of biogrowth. The validity of the model was verified with laboratory scale experiments. In the range of the model, the predicted values differ by a maximum of 11% from experimental results.
Show less - Date Issued
- 2003
- PURL
- http://purl.flvc.org/fcla/dt/13026
- Subject Headings
- Saline water conversion--Reverse osmosis process, Reverse osmosis--Computer simulation
- Format
- Document (PDF)
- Title
- Evaluation of alumina-based stationary phases for the separations of proteins and peptides by high performance liquid chromatography.
- Creator
- Raghani, Anil Ratilal., Florida Atlantic University, Haky, Jerome E.
- Abstract/Description
-
Alumina-based stationary phases are evaluated for the separations of proteins and peptides by reversed phase high performance liquid chromatography. Separations are compared to those obtained on a widely-used octadecylsilane (ODS) phase. The separations of peptides on alumina-based stationary phases are found to be superior while separations of proteins are inferior as compared to those found on ODS phase. The superior performance of peptide separations on alumina-based columns is attributed...
Show moreAlumina-based stationary phases are evaluated for the separations of proteins and peptides by reversed phase high performance liquid chromatography. Separations are compared to those obtained on a widely-used octadecylsilane (ODS) phase. The separations of peptides on alumina-based stationary phases are found to be superior while separations of proteins are inferior as compared to those found on ODS phase. The superior performance of peptide separations on alumina-based columns is attributed to lower pore size and uniquely-shaped particles of the alumina. The retentions of peptides and proteins on both alumina and silica-based stationary phases are shown to be governed by hydrophobic interaction mechanisms.
Show less - Date Issued
- 1991
- PURL
- http://purl.flvc.org/fcla/dt/14719
- Subject Headings
- Proteins--Separation, High performance liquid chromatography
- Format
- Document (PDF)
- Title
- Factors affecting success in organic chemistry.
- Creator
- Zaplatynski, Andrea Maria, Florida Atlantic University, Haky, Jerome E.
- Abstract/Description
-
In this study we correlate academic and non-academic descriptors with Organic Chemistry final grades for students enrolled at a Florida public university. Using multiple regression analysis, the following predictors are analyzed for a sample population of 904 students: age, gender, ethnicity, academic classification, SAT scores, major, overall grade point average (GPA), semesters lapsed between courses, institution where General Chemistry was taken, prerequisite grades, and number of math and...
Show moreIn this study we correlate academic and non-academic descriptors with Organic Chemistry final grades for students enrolled at a Florida public university. Using multiple regression analysis, the following predictors are analyzed for a sample population of 904 students: age, gender, ethnicity, academic classification, SAT scores, major, overall grade point average (GPA), semesters lapsed between courses, institution where General Chemistry was taken, prerequisite grades, and number of math and science courses taken with their respective grades. Results indicate strong correlations exist between final grade in Organic Chemistry, GPA and General Chemistry final grade. Additionally, Organic Chemistry final grades correlate with academic course load and the type of institution where General Chemistry was studied. We believe these results can be employing as a tool for advising students in planning their academic programs.
Show less - Date Issued
- 2006
- PURL
- http://purl.flvc.org/fcla/dt/13389
- Subject Headings
- Chemistry, Organic--Study and teaching, Education, Secondary, Regression analysis, Academic achievement--Education (Higher)--Florida
- Format
- Document (PDF)
- Title
- Para-aminophenyl alumina: A new stationary phase for high-performance liquid chromatography.
- Creator
- Calixte, Mincs-Elie., Florida Atlantic University, Haky, Jerome E.
- Abstract/Description
-
Surface-modified alumina containing covalently-bonded p-aminophenyl groups was prepared by refluxing chromatographic grade alumina with p-aminophenylphosphonic acid in n-butanol. The resulting material, p-aminophenylalumina (PAPA), was evaluated for use as a stationary phase in high performance liquid chromatography (HPLC). When used with mobile phases consisting of acetonitrile and water, retention of solutes on the PAPA phase exhibited normal phase behavior, as evidenced by the increases in...
Show moreSurface-modified alumina containing covalently-bonded p-aminophenyl groups was prepared by refluxing chromatographic grade alumina with p-aminophenylphosphonic acid in n-butanol. The resulting material, p-aminophenylalumina (PAPA), was evaluated for use as a stationary phase in high performance liquid chromatography (HPLC). When used with mobile phases consisting of acetonitrile and water, retention of solutes on the PAPA phase exhibited normal phase behavior, as evidenced by the increases in solute retention times with increasing percentages of acetonitrile. Excellent separations of carbohydrate mixtures were obtained on the PAPA stationary phase. Comparisons of the chromatographic properties the PAPA phase with those of commercial aminoalkyl silica stationary phases were also performed.
Show less - Date Issued
- 1998
- PURL
- http://purl.flvc.org/fcla/dt/15570
- Subject Headings
- Stationary phase (Chromatography), Liquid chromatography, Aluminum alloys--Bonding
- Format
- Document (PDF)
- Title
- Synthesis characterization and ion exchange properties of aluminum phosphonates.
- Creator
- McCormack, Rupert Garth, Florida Atlantic University, Haky, Jerome E.
- Abstract/Description
-
Three aluminum organophosphonate compounds; aluminum phenylphosphonate, aluminum octylphosphonate, and aluminum octadecylphosphonate, have been synthesized by refluxing aluminum nitrate with an excess of the appropriate organophosphonic acid in aqueous, methanol, or butanol solvents respectively. Each of these compounds was found to have pillared layered structures and ligand to metal ratios of 2:1. Additionally, these compounds were shown to exhibit cation exchange properties. In contrast to...
Show moreThree aluminum organophosphonate compounds; aluminum phenylphosphonate, aluminum octylphosphonate, and aluminum octadecylphosphonate, have been synthesized by refluxing aluminum nitrate with an excess of the appropriate organophosphonic acid in aqueous, methanol, or butanol solvents respectively. Each of these compounds was found to have pillared layered structures and ligand to metal ratios of 2:1. Additionally, these compounds were shown to exhibit cation exchange properties. In contrast to that observed for conventional cation-exchange resins, the exchange capacities of these compounds are larger for small cations, such as Li+ and Na+, than for larger ions such as Na+ and K+. The results indicate a size selectivity which is directly related to the accessibility of these ions to the exchangeable sites of these compounds.
Show less - Date Issued
- 2001
- PURL
- http://purl.flvc.org/fcla/dt/12748
- Subject Headings
- Inorganic ion exchange materials, Phosphonates, Aluminum compounds
- Format
- Document (PDF)
- Title
- High performance liquid chromatographic properties of reversed phase alumina.
- Creator
- Vemulapalli, Shobha, Florida Atlantic University, Haky, Jerome E.
- Abstract/Description
-
The chromatographic properties of Octadecylsilica (ODS), Octadecylalumina (ODA), Polybutadiene coated alumina (PBD), Styrene-divinylbenzene copolymer (ACT-1) were investigated to evaluate Octanol-Water partition coefficient, log P, using a correlation method of High Performance Liquid Chromatographic (HPLC) capacity factor, k', and literature partition coefficient values. This study revealed the superior chromatographic characteristics of ODA material and its potential for the evaluation of...
Show moreThe chromatographic properties of Octadecylsilica (ODS), Octadecylalumina (ODA), Polybutadiene coated alumina (PBD), Styrene-divinylbenzene copolymer (ACT-1) were investigated to evaluate Octanol-Water partition coefficient, log P, using a correlation method of High Performance Liquid Chromatographic (HPLC) capacity factor, k', and literature partition coefficient values. This study revealed the superior chromatographic characteristics of ODA material and its potential for the evaluation of log P values of organic compounds, in particular, bases. The log P(HPLC) values evaluated using the log k'-log P regression equation obtained from a set of standards on ODA appeared to be accurate. These values matched with the theoretical calculations supporting the accuracy of the HPLC method.
Show less - Date Issued
- 1990
- PURL
- http://purl.flvc.org/fcla/dt/14657
- Subject Headings
- High performance liquid chromatography--Methodology, Liquid chromatography--Methodology, Oxides
- Format
- Document (PDF)
- Title
- Composition of aluminum phenylphosphonate solutions: Evidence from nuclear magnetic resonance.
- Creator
- Schulz, Hans-Erich., Florida Atlantic University, Haky, Jerome E.
- Abstract/Description
-
27Al nuclear magnetic resonance (NMR) has been employed to study the structure of aqueous aluminum nitrate solutions in the presence of phenylphosphonic acid, potassium dihydrogen phosphate and phosphoric acid. Evidence has been obtained which indicates that in aqueous solution, aluminum ions can be complexed with phosphonate or phosphate in either a 1:1 or 2:1 molar ratio, respectively. The relative percentages of these complexes in solution are shown to be dependent on the ratio of aluminum...
Show more27Al nuclear magnetic resonance (NMR) has been employed to study the structure of aqueous aluminum nitrate solutions in the presence of phenylphosphonic acid, potassium dihydrogen phosphate and phosphoric acid. Evidence has been obtained which indicates that in aqueous solution, aluminum ions can be complexed with phosphonate or phosphate in either a 1:1 or 2:1 molar ratio, respectively. The relative percentages of these complexes in solution are shown to be dependent on the ratio of aluminum nitrate to phosphonate or phosphate as well as the degree of ionization of the phosphorus species.
Show less - Date Issued
- 1995
- PURL
- http://purl.flvc.org/fcla/dt/15232
- Subject Headings
- Nuclear magnetic resonance, Aluminum alloys--Bonding
- Format
- Document (PDF)
- Title
- Comparison of alkyl-bonded alumina and silica stationary phases for peptide and protein separations by high performance liquid chromatography.
- Creator
- Williams, David Clinton, Florida Atlantic University, Haky, Jerome E.
- Abstract/Description
-
The applicability of a recently developed octadecylalumina (ODA) stationary phase for the preparative separations of proteins and peptides is compared with that of conventional Octadecylsilica (ODS) phases. Chromatographic peak widths, peaks areas, and recoveries of polypeptides were obtained from both types of phases. The ODA phase compares favorably with the ODS phase on small peptides, but exhibits low recoveries on high molecular weight proteins. The results are attributed to the unique...
Show moreThe applicability of a recently developed octadecylalumina (ODA) stationary phase for the preparative separations of proteins and peptides is compared with that of conventional Octadecylsilica (ODS) phases. Chromatographic peak widths, peaks areas, and recoveries of polypeptides were obtained from both types of phases. The ODA phase compares favorably with the ODS phase on small peptides, but exhibits low recoveries on high molecular weight proteins. The results are attributed to the unique fused-microplatelet shape of the ODA particles.
Show less - Date Issued
- 1996
- PURL
- http://purl.flvc.org/fcla/dt/15260
- Subject Headings
- High performance liquid chromatography, Proteins--Separation, Peptides--Separation
- Format
- Document (PDF)
- Title
- A study of the effect of the hydrophobicity of organic compounds on their micelle-water partition coefficients in aqueous solutions of cetyltrimethylammonium bromide.
- Creator
- Vijayabhaskar, C. R., Florida Atlantic University, Haky, Jerome E.
- Abstract/Description
-
The effect of the hydrophobicity of organic compounds on their micelle-water partition coefficients was investigated. The micelle-water partition coefficients were obtained by UV/VIS spectroscopy and correlated with their octanol-water partition coefficients. The octanol-water partition coefficient of an organic compound is a measure of its hydrophobicity. Hydrophobicity alone did not influence the micelle-water partition coefficients. Further research is required to substantiate present...
Show moreThe effect of the hydrophobicity of organic compounds on their micelle-water partition coefficients was investigated. The micelle-water partition coefficients were obtained by UV/VIS spectroscopy and correlated with their octanol-water partition coefficients. The octanol-water partition coefficient of an organic compound is a measure of its hydrophobicity. Hydrophobicity alone did not influence the micelle-water partition coefficients. Further research is required to substantiate present findings and obtain additional related information.
Show less - Date Issued
- 1994
- PURL
- http://purl.flvc.org/fcla/dt/15000
- Subject Headings
- Hydrophobic surfaces, Micelles, Surface chemistry, Surface active agents, Detergents
- Format
- Document (PDF)
- Title
- A stability study of octadecylalumina columns for use in HPLC.
- Creator
- Goldberg, James Vincent, Florida Atlantic University, Haky, Jerome E.
- Abstract/Description
-
Chromatographic stability studies of an alumina-based reversed phase, ODA, stationary phase were performed. These studies involved monitoring the chromatographic performance of columns packed with the ODA phase after separate, continuous treatment with aqueous solutions of trifluoroacetic acid and sodium hydroxide over a period of several weeks. Chromatographic performance of the ODA columns undergoing treatment with these mobile phases was evaluated by comparing changes in chromatographic...
Show moreChromatographic stability studies of an alumina-based reversed phase, ODA, stationary phase were performed. These studies involved monitoring the chromatographic performance of columns packed with the ODA phase after separate, continuous treatment with aqueous solutions of trifluoroacetic acid and sodium hydroxide over a period of several weeks. Chromatographic performance of the ODA columns undergoing treatment with these mobile phases was evaluated by comparing changes in chromatographic capacity factors, resolutions, plate numbers, and peak asymmetries of a test mixture consisting of uracil, phenol, aniline, methyl benzoate, m-toluidine, N,N-dimethylaniline, and toluene. The results indicate that the alumina-based ODA phase is stable under acidic conditions (pH 2--3) and exceptionally stable to chemical degradation under alkaline conditions (pH ∼ 11).
Show less - Date Issued
- 2000
- PURL
- http://purl.flvc.org/fcla/dt/12681
- Subject Headings
- Chromatographic analysis, High performance liquid chromatography
- Format
- Document (PDF)
- Title
- Employment of modern analytical methods for adsorption studies and pharmaceutical analysis.
- Creator
- Foss, Wendy Marie, Florida Atlantic University, Haky, Jerome E.
- Abstract/Description
-
Ultraviolet spectrophotometry was employed to investigate the adsorption of phenylphosphonic acid onto the surface of alumina from aqueous solution. It was found that an initial chemisorption occurred with monolayer coverage, reaching a maximum at a solution pH of 3.0. The results were interpreted as indicating that this and related adsorptions are controlled by ligand exchange processes involving electrostatic attraction between oppositely-charged species. In a separate project, high...
Show moreUltraviolet spectrophotometry was employed to investigate the adsorption of phenylphosphonic acid onto the surface of alumina from aqueous solution. It was found that an initial chemisorption occurred with monolayer coverage, reaching a maximum at a solution pH of 3.0. The results were interpreted as indicating that this and related adsorptions are controlled by ligand exchange processes involving electrostatic attraction between oppositely-charged species. In a separate project, high performance liquid chromatography was employed for the quantitative analysis of aminophylline in commercial thigh cream formulations. The analysis required derivatization of the compound by dansylation under carefully-controlled conditions. This enhanced its detection and separation from other cream components.
Show less - Date Issued
- 1997
- PURL
- http://purl.flvc.org/fcla/dt/15404
- Subject Headings
- Adsorption, Spectrophotometry, Chromatographic analysis, Solution (Chemistry)
- Format
- Document (PDF)
- Title
- Investigation of perfluoroalkyl bonded alumina-based stationary phases for reversed phase high performance liquid chromatography applications.
- Creator
- Mannschreck, Tina Marie, Florida Atlantic University, Haky, Jerome E.
- Abstract/Description
-
The general chromatographic properties of perfluoroalkyl-bonded alumina-based stationary phases were evaluated by comparing hydrophobicities and selectivities to octadecyl-bonded silica phases. Potential applications for the perfluoroalkyl-bonded alumina-based stationary phases were also investigated by analyzing octapeptide mixtures as well as separations which employed totally aqueous mobile phases. The fluorinated alumina-based stationary phases investigated in this study were found to...
Show moreThe general chromatographic properties of perfluoroalkyl-bonded alumina-based stationary phases were evaluated by comparing hydrophobicities and selectivities to octadecyl-bonded silica phases. Potential applications for the perfluoroalkyl-bonded alumina-based stationary phases were also investigated by analyzing octapeptide mixtures as well as separations which employed totally aqueous mobile phases. The fluorinated alumina-based stationary phases investigated in this study were found to possess different chromatographic properties compared to octadecylsilica columns.
Show less - Date Issued
- 1994
- PURL
- http://purl.flvc.org/fcla/dt/15055
- Subject Headings
- Chromatographic analysis, High performance liquid chromatography
- Format
- Document (PDF)
- Title
- Investigation of dynamically coated alumina stationary phases for reversed-phase high-performance liquid chromatography.
- Creator
- Ferguson, Veronica, Florida Atlantic University, Haky, Jerome E.
- Abstract/Description
-
Dynamically coated alumina (DCA) was prepared by pumping mobile phase containing methanol and concentration of 10mM Sodium Lauryl Sulphate (SLS), an anionic surfactant prepared in water, through a bare alumina column. The mechanism of separation of a test mixture were characteristic of reversed phase chromatography as evident in the decreased retention time as the percentage of methanol increased. However, the effects of changing the pH of the mobile phase on retention of solutes were...
Show moreDynamically coated alumina (DCA) was prepared by pumping mobile phase containing methanol and concentration of 10mM Sodium Lauryl Sulphate (SLS), an anionic surfactant prepared in water, through a bare alumina column. The mechanism of separation of a test mixture were characteristic of reversed phase chromatography as evident in the decreased retention time as the percentage of methanol increased. However, the effects of changing the pH of the mobile phase on retention of solutes were different than that expected in reversed phase separations, indicating the presence of another retention mechanism. Excellent resolutions, peak shapes and peak symmetries were obtained using the DCA conditions and were comparable to similar separations performed on an ODA (octadecylalumina) column. Comparisons of retentions of a variety of organic compounds on DCA with those of commercial ODS (octadecylsilica) and ODA phases were also performed.
Show less - Date Issued
- 1999
- PURL
- http://purl.flvc.org/fcla/dt/15673
- Subject Headings
- High performance liquid chromatography, Aluminum coating
- Format
- Document (PDF)
- Title
- Synthesis and characterization of aluminum phenylphosphonate.
- Creator
- Brady, Jennifer Beth., Florida Atlantic University, Haky, Jerome E.
- Abstract/Description
-
A new aluminum phenylphosphonate compound, AlH(C6H5P03)2 was obtained by refluxing a mixture of aluminum nitrate and excess phenylphosphonic acid in water. The compound was characterized by elemental analysis, thermogravimetric analysis, infrared spectroscopy, x-ray powder diffraction and nuclear magnetic resonance spectroscopy. The data indicates that an intercalation compound formed, with an interlayer spacing of 15 angstroms. The compound contains both tetrahedrally and octahedrally...
Show moreA new aluminum phenylphosphonate compound, AlH(C6H5P03)2 was obtained by refluxing a mixture of aluminum nitrate and excess phenylphosphonic acid in water. The compound was characterized by elemental analysis, thermogravimetric analysis, infrared spectroscopy, x-ray powder diffraction and nuclear magnetic resonance spectroscopy. The data indicates that an intercalation compound formed, with an interlayer spacing of 15 angstroms. The compound contains both tetrahedrally and octahedrally coordinated aluminum atoms, suggesting the presence of two or more crystalline phases or a complex unit cell structure. The compound also possesses some unique ion-exchange properties.
Show less - Date Issued
- 1996
- PURL
- http://purl.flvc.org/fcla/dt/15314
- Subject Headings
- Aluminum compounds, Phosphonates
- Format
- Document (PDF)
- Title
- Simplex optimization of aluminum analysis by electrothermal atomic absorption spectrometry.
- Creator
- Creelman, David Karl., Florida Atlantic University, Haky, Jerome E.
- Abstract/Description
-
A novel simplex method was applied for the systematic selection of optimal concentrations of two matrix modifiers, nitric acid and magnesium nitrate, for aluminum analysis in aqueous samples using electrothermal atomic absorption spectrometry. Independent optimizations of sensitivity were performed over several practical concentration ranges for each matrix modifier and optimum concentrations were chosen by comparison of data obtained for the resulting simplexes. The results indicate a strong...
Show moreA novel simplex method was applied for the systematic selection of optimal concentrations of two matrix modifiers, nitric acid and magnesium nitrate, for aluminum analysis in aqueous samples using electrothermal atomic absorption spectrometry. Independent optimizations of sensitivity were performed over several practical concentration ranges for each matrix modifier and optimum concentrations were chosen by comparison of data obtained for the resulting simplexes. The results indicate a strong interdependency between magnesium and nitric acid in the achievement of conditions for optimum sensitivity. Using the optimized conditions, detection limits of less than 7 parts per billion of aluminum were achieved, with relative standard deviations of less than 10%. A variety of aqueous samples were analyzed yielding relative standard deviations from 2 to 10%.
Show less - Date Issued
- 1997
- PURL
- http://purl.flvc.org/fcla/dt/15399
- Subject Headings
- Atomic absorption spectroscopy, Aluminum--Analysis
- Format
- Document (PDF)
- Title
- Peer Led Team Learning into Organic Chemistry.
- Creator
- Deacon, Lisa, Rezler, Evonne, Haky, Jerome E., Sempertegui Plaza, Tito S.
- Abstract/Description
-
A web-based learning system for Organic Chemistry is being integrated into a Peer-Led Team Learning (PLTL) environment to restructure the existing Organic Chemistry I discussion (OrgoBOND) sections to enhance student learning, improve overall grades, and lower the Organic Chemistry I DFW rates. Students taking Organic Chemistry I are required to participate in a section of OrgoBOND utilizing the web-based learning system in a smaller classroom than in previous discussion sessions. Student...
Show moreA web-based learning system for Organic Chemistry is being integrated into a Peer-Led Team Learning (PLTL) environment to restructure the existing Organic Chemistry I discussion (OrgoBOND) sections to enhance student learning, improve overall grades, and lower the Organic Chemistry I DFW rates. Students taking Organic Chemistry I are required to participate in a section of OrgoBOND utilizing the web-based learning system in a smaller classroom than in previous discussion sessions. Student performance will be compared to that of students in future semesters participating in the same small PLTL setting, but with traditional recitation format. The advantages of introducing a web-based learning system into PLTL discussion sessions are (1) providing “hints,” (2) offering multiple attempts per question, and (3) instant grading and feedback. The computer assignments are unique to each student and reflect the topic recently reviewed in lecture. We will report on the preliminary results from data being collected on student performance, satisfaction levels, and retention rate changes.
Show less - Date Issued
- 2014
- PURL
- http://purl.flvc.org/fau/fd/FA0005010
- Subject Headings
- College students --Research --United States.
- Format
- Document (PDF)
- Title
- Synthesis and structural characterization of intermediates towards the preparation of a polyphosphonate ester containing L-dopa for the potential treatment of Parkinson's disease.
- Creator
- Chamely-Wiik, Donna M., Florida Atlantic University, Haky, Jerome E., Carraher, Charles E., Charles E. Schmidt College of Science, Department of Chemistry and Biochemistry
- Abstract/Description
-
We have synthesized intermediates towards the preparation of a polyphosphonate ester containing L-dopa for the potential treatment of Parkinson's disease. A synthetic strategy was devised to be more reproducible than the original strategy. We discovered some very interesting chemistry of one of the intermediates produced from this new scheme. We synthesized L-N-(butyloxycarbonyl)-3-(3-hydroxy-ethyl-4-(benzyloxy)-phenyl)alanine benzylester, a compound containing a secondary alcohol moiety that...
Show moreWe have synthesized intermediates towards the preparation of a polyphosphonate ester containing L-dopa for the potential treatment of Parkinson's disease. A synthetic strategy was devised to be more reproducible than the original strategy. We discovered some very interesting chemistry of one of the intermediates produced from this new scheme. We synthesized L-N-(butyloxycarbonyl)-3-(3-hydroxy-ethyl-4-(benzyloxy)-phenyl)alanine benzylester, a compound containing a secondary alcohol moiety that had a unique set of characteristics. Upon reduction of the N-(tert-butyloxycarbonyl)-3-(3-acetyl-4-benzyloxyphenyl)-L-alanine benzylester, which contained a ketone moiety, to produce the secondary alcohol, we discovered that the materials that were formed included a pair of diastereomers of the secondary alcohol, each diastereomer also exhibiting two individually stable conformational isomers. We believe that the conformational isomers were generated by rotation of the C-N bond of the BOC carbamate, and were so stable that they could be separated by HPLC and NMR techniques. Energy optimization studies and molecular modeling techniques were performed using HyperChem, and rotational barrier energy values were calculated for the different conformational isomers for each of the diastereomers. HPLC and NMR techniques were also used to obtain information about these materials. Using the calculated data from these studies, and analyzing the HPLC chromatograms and NMR spectra we were able to fully determine the assignments for the diastereomers and the individual conformational isomers. We discovered that the SS form was synthesized preferentially over the SR form and that in both cases the E conformation was energetically more stable than the Z form. Octanol/water partition coefficient values (Log P0ct) were also determined and compared to L-dopa and dopamine. We concluded that the values for the dimeric compound that we synthesized and many of its potential products of degradation were significantly higher than that for both L-dopa and dopamine. This may be an indication that this material has a higher degree of lipophilicity than L-dopa itself, having more potential to cross the blood brain barrier. We believe that these intermediate materials serve as good indication of how a polyphosphonate ester containing L-dopa would compare as a potential drug for Parkinson's disease.
Show less - Date Issued
- 2004
- PURL
- http://purl.flvc.org/fcla/dt/12108
- Subject Headings
- Parkinson's disease--Treatment, Antiparkinsonian agents, Dopa, Organophosphorus compounds--Synthesis, Chemistry, Analytic
- Format
- Document (PDF)
- Title
- Synthesis and Characterization of Organotin Polyamine Esters from Diglycine.
- Creator
- Slawek, Paul Peter, Carraher, Charles E., Haky, Jerome E., Florida Atlantic University, Charles E. Schmidt College of Science, Department of Chemistry and Biochemistry
- Abstract/Description
-
This research is part of a long-term project aimed at elucidating important structural features, of both ligands and metals, that are needed to produce effective anti-cancer agents. The specific goal is the synthesis of organotin polymers containing amino acids, in this case the diamino acid diglycine. The desired materials were synthesized with percent yields ranging from 32-99%. The products were synthesized employing the interfacial polymerization technique. The polymers were then...
Show moreThis research is part of a long-term project aimed at elucidating important structural features, of both ligands and metals, that are needed to produce effective anti-cancer agents. The specific goal is the synthesis of organotin polymers containing amino acids, in this case the diamino acid diglycine. The desired materials were synthesized with percent yields ranging from 32-99%. The products were synthesized employing the interfacial polymerization technique. The polymers were then characterized utilizing the following physical characterization techniques: light scattering photometry (LS), Infrared spectroscopy (IR), nuclear magnetic resonance spectroscopy (NMR), and matrix assisted laser desorption mass spectroscopy (MALDI). Physical characterization showed evidence of formation of desired adducts in addition to data that was consistent with the formation of materials containing multiple repeat units. The materials were then analyzed for biological activity. The synthesized materials displayed the ability to inhibit tested cancer cell lines.
Show less - Date Issued
- 2018
- PURL
- http://purl.flvc.org/fau/fd/FA00013158
- Subject Headings
- Organotin Compounds, Glycylglycine, Antineoplastic agents--Development
- Format
- Document (PDF)
- Title
- Comparison of alkyl-bonded alumina-based stationary phases for peptide separation by high performance liquid chromatography.
- Creator
- Ramdial, Nirmala Debra-Ann, Florida Atlantic University, Haky, Jerome E., Department of Chemistry and Biochemistry, Charles E. Schmidt College of Science
- Abstract/Description
-
The performance of several alkyl-bonded alumina-based stationary phases was evaluated by comparing the separation of synthetic octapeptide and polypeptide mixtures and tryptic digests of larger proteins. These phases were of differing pore diameter, alkyl chain length modification and particle shape and size. The separations were compared to standard silica phases. The narrow pore octadecyl bonded alumina phase outperformed the other alumina and silica phases in terms of separation efficiency...
Show moreThe performance of several alkyl-bonded alumina-based stationary phases was evaluated by comparing the separation of synthetic octapeptide and polypeptide mixtures and tryptic digests of larger proteins. These phases were of differing pore diameter, alkyl chain length modification and particle shape and size. The separations were compared to standard silica phases. The narrow pore octadecyl bonded alumina phase outperformed the other alumina and silica phases in terms of separation efficiency and mobile phase resistance. Superior performance is attributed to the enhanced solute mass transfer properties and the unique morphology of the microplatelet alumina particles. The mechanism of separation gradually changes with increasing size of the peptide.
Show less - Date Issued
- 1992
- PURL
- http://purl.flvc.org/fcla/dt/14831
- Subject Headings
- Peptides--Separation, Liquid chromatography
- Format
- Document (PDF)
