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Title: 9,11-secogorgosterol biosynthesis in gorgonians.
Creator: Kellman, Jaelle, Florida Atlantic University, Kerr, Russell G., Charles E. Schmidt College of Science, Department of Chemistry and Biochemistry
Abstract/Description: 9,11-secogorgosterol is a secondary metabolite from the gorgonian Pseudopterogorgia americana which acts as a chemical defense. The soft coral lives in a symbiotic association with unicellular algae known as zooxanthellae. A biosynthetic investigation, using in vivo and in vitro methods, has resulted in the identification of the metabolic precursor of 9,11-secogorgosterol as gorgosterol. This finding is significant as it indicates that the conversion of gorgosterol to 9,11-secogorgosterol is...
Show more9,11-secogorgosterol is a secondary metabolite from the gorgonian Pseudopterogorgia americana which acts as a chemical defense. The soft coral lives in a symbiotic association with unicellular algae known as zooxanthellae. A biosynthetic investigation, using in vivo and in vitro methods, has resulted in the identification of the metabolic precursor of 9,11-secogorgosterol as gorgosterol. This finding is significant as it indicates that the conversion of gorgosterol to 9,11-secogorgosterol is due to gorgonian metabolism. Since gorgosterol is known to be a product of zooxanthellae metabolism, this would be the first example of a defensive secondary metabolite being produced by two organisms living in symbiosis. A viable acetone powder has been generated from the crude cell-free extract and has demonstrated the efficient transformation of gorgosterol to 9, 11-secogorgosterol. This indicates possible future value as a synthetic tool for secosterol production.
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Date Issued: 1995
PURL: http://purl.flvc.org/fcla/dt/15180
Subject Headings: Sterols--Synthesis, Alcyonacea
Format: Document (PDF)

Title: Methodologies Towards One Pot Synthesis of α-Arylated Amino Esters And Applications in Total Synthesis.
Creator: Samanta, Shyam S., Roche, Stephane P., Florida Atlantic University, Charles E. Schmidt College of Science, Department of Chemistry and Biochemistry
Abstract/Description: In this dissertation, we discuss the development of a synthetic method to functionalize various α-haloglycine esters, as key precursors to a large variety of non-proteinogenic α-amino acids (Xaas). At first, we discovered a very practical and high yielding acetyl chloride-mediated cascade reaction to synthesize α-arylated amino esters in one-pot. In this multicomponent reaction (MCR), a primary carbamate was condensed with a glyoxylate, followed by an in situ halogenation which proved...
Show moreIn this dissertation, we discuss the development of a synthetic method to functionalize various α-haloglycine esters, as key precursors to a large variety of non-proteinogenic α-amino acids (Xaas). At first, we discovered a very practical and high yielding acetyl chloride-mediated cascade reaction to synthesize α-arylated amino esters in one-pot. In this multicomponent reaction (MCR), a primary carbamate was condensed with a glyoxylate, followed by an in situ halogenation which proved essential to trigger the final Friedel−Crafts functionalization. After careful reaction optimization, a plethora of arene nucleophiles were reacted with high regioselectively in CHCl3 at low temperatures (Method A) while less activated arenes reacted more cleanly in CH3CN and at higher temperatures (Method B). To broaden the scope of this reaction to acid sensitive nucleophiles, a one-pot reaction was designed via evaporation of all acid by-products at the α-haloglycine stage. The anion-binding Schreiner’s thiourea catalyst proved to be extremely efficient to promote this complementary approach (Method C) which relies on the chloride leaving group activation by the catalyst to assist the functionalization stage and deliver the α-amino ester product. In the second chapter, some highly practical and efficient preparations of α-haloglycine esters in one-pot have been developed to generate useful precursors of non-proteinogenic α-amino esters. Also, a mild and unique AcOH(cat.)/AcCl system was found to promote an autocatalytic-like condensation/deoxy halogenation and facilitate the multicomponent assembly of non-proteinogenic α-amino esters. Friedel–Crafts reaction between α-chloroglycine and N-methylindole have been studied in details to understand the mechanistic intricacy of this reaction. Our findings through the initial kinetic profiling support that the arylation likely proceeds via a SN1-like (or SN2C+) mechanism. In third chapter, we discuss the development of the most challenging α,α-disubstituted amino esters in a multicomponent fashion. Our results highlight that the MCR proceeds via the formation of an enamide intermediate, which is further tautomerized to corresponding iminium to produce the desired product. In collaboration with Eli Lilly at the Automated Synthesis Laboratory (ASL), we have developed silver (I) salts mediated Friedel–Crafts reaction for synthesis of α-trifluoromethylated α-amino esters on a fully automatized robot.
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Date Issued: 2018
PURL: http://purl.flvc.org/fau/fd/FA00013160
Subject Headings: Esters, Synthesis, Amino Acids
Format: Document (PDF)

Title: Synthesis of N-substituted Pyrrolin-2-ones.
Creator: Mattern, R.-H., Harbor Branch Oceanographic Institute
Date Issued: 1996
PURL: http://purl.flvc.org/FCLA/DT/3331910
Subject Headings: Stereoisomers--Synthesis, Bioactive compounds--Synthesis, Pyrrolidines
Format: Document (PDF)

Title: Toward the synthesis of organic moieties for use in luminescent lanthanide materials: from benzodithiophene based linkers to a series of 2,3 pyridinedicarboxylate coordination polymers.
Creator: Ramirez, Amanda Lyn Staggers., Charles E. Schmidt College of Science, Department of Chemistry and Biochemistry
Abstract/Description: The main focus of this thesis is to present the structural and photophysical characteristics of the coordination polymers [Ln(C7H3NO4)(C7H4NO4)(H2O)]n (Ln is Pr, Nd, Sm, Eu, and Tb), as well as attempting to synthesize the novel organic linker 4,4'(4,8-Dihydrobenzo[1,2-b:4,5-b']dithiophene-4,8-diyl)dibenzoic acid (BDTDC). Various lanthanide salts were coordinated with 2,3-pyridinecarboxylate (2,3- pydc) via hydrothermal synthesis. ... Progress was made toward the synthesis of a novel metal...
Show moreThe main focus of this thesis is to present the structural and photophysical characteristics of the coordination polymers [Ln(C7H3NO4)(C7H4NO4)(H2O)]n (Ln is Pr, Nd, Sm, Eu, and Tb), as well as attempting to synthesize the novel organic linker 4,4'(4,8-Dihydrobenzo[1,2-b:4,5-b']dithiophene-4,8-diyl)dibenzoic acid (BDTDC). Various lanthanide salts were coordinated with 2,3-pyridinecarboxylate (2,3- pydc) via hydrothermal synthesis. ... Progress was made toward the synthesis of a novel metal-organic framework linker BDTDC. Synthesis of the intermediate benzo[1,2-b:4,5-b']dithiophene as well as the determination of the crystal structure, were performed successfully and are reported herein.
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Date Issued: 2013
PURL: http://purl.flvc.org/fcla/dt/3362561
Subject Headings: Metathesis (Chemistry), Supramolecular chemistry, Organic compounds, Synthesis, Macromolecules, Synthesis
Format: Document (PDF)

Title: Synthesis and new reactions of allenyl carbonyls: studies towards the total synthesis of anti-thrombotic natural products Vitisinol D and C.
Creator: Maity, Pradip., Charles E. Schmidt College of Science, Department of Chemistry and Biochemistry
Abstract/Description: We report here the development of new and more general synthetic pathways for the preparation of allenyl and alkynyl carbonyls. These highly dense functionalized compounds were utilized as key intermediates for the synthesis of [3.2.1] and [3.3.1] bicyclic framework, the motifs found in many natural products. A convenient method described for the dehydration of ketoesters to generate conjugated and deconjugated alkynyl esters and conjugated allenyl esters. This sequential one-pot method...
Show moreWe report here the development of new and more general synthetic pathways for the preparation of allenyl and alkynyl carbonyls. These highly dense functionalized compounds were utilized as key intermediates for the synthesis of [3.2.1] and [3.3.1] bicyclic framework, the motifs found in many natural products. A convenient method described for the dehydration of ketoesters to generate conjugated and deconjugated alkynyl esters and conjugated allenyl esters. This sequential one-pot method involves the formation of a vinyl triflate monoanion intermediate that leads to the selective formation of alkynes or allenes depending on additives and conditions used. Product outcomes appear to be a function of unique monoand dianion mechanisms which are described. Our design of a Morita-Baylis-Hilman (MBH) reaction to include a fast silyl 1,3- Brook rearrangement has enabled the first ever anion-catalysis. This new reaction makes possible the addition of both aliphatic and aromatic aldehydes to s ilylallenes leading to carbinol allenoates. These new MBH reactions products allow for a fasttracked synthesis of [3.2.1] bisoxa-bicycles which make up the framework of many biologically active natural products including Vitisinol D. The development of cyclic addition of hydrazine nitrogen to unactivated alkynes catalyzed by non-metals is reported. Starting from readily accessible silyl allenyl esters, alkynyl hydrazines are prepared in one step and subsequently undergo unprecedented cyclization reactions in the presence of ammonium and phosphonium catalysts leading to dehydro-azaproline products. These heterocycles were also produced in high enantiomeric excesses using chiral ammonium phase transfer catalysts via a kinetic resolution pathway., The racemic synthesis of fully functionalized bicyclic core of Vitisinol D was achieved using allenyl ester as a key intermediate. The required electron withdrawing group (EWG) at the position was screened for better addition followed by the compatibility towards successive transformation and, finally, the ease of removal. A reductive aldol method to transform lactone-enol to the desired [3.2.1] bicycle was extensively studied to understand the stereoelectronic requirements for the formation of such bicyclic structures. Due to the necessity of selective protection and deprotection of many phenolic and aliphatic hydroxyls as well as ester groups, orthogonal protecting groups were established accordingly.
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Date Issued: 2011
PURL: http://purl.flvc.org/FAU/3332717
Subject Headings: Organic compounds, Synthesis, Carbonyl compounds, Synthesis, Cardiovascular system, Diseases, Treatment
Format: Document (PDF)

Title: Automatic V/UV/S classification of continuous speech without a predetermined training set.
Creator: Leung, Chung Sing., Florida Atlantic University, Kostopoulos, George, College of Engineering and Computer Science, Department of Computer and Electrical Engineering and Computer Science
Abstract/Description: In speech analysis, a Voiced-Unvoiced-Silence (V/UV/S) decision is performed through pattern recognition, based on measurements made on the signal. The examined speech segment is assigned to a particular class, V/UV/S, based on a minimum probability-of-error decision rule which is obtained under the assumption that the measured parameters are distributed according to a multidimensional Gaussian probability density function. The means and covariances for the Gaussian distribution are...
Show moreIn speech analysis, a Voiced-Unvoiced-Silence (V/UV/S) decision is performed through pattern recognition, based on measurements made on the signal. The examined speech segment is assigned to a particular class, V/UV/S, based on a minimum probability-of-error decision rule which is obtained under the assumption that the measured parameters are distributed according to a multidimensional Gaussian probability density function. The means and covariances for the Gaussian distribution are determined from manually classified speech data included in a training set. If the recording conditions vary considerably, a new set of training data is required. With the assumption that all three classes exist in the incoming speech signal, this research describes an automatic parametric learning method. Such a method estimates the means and covariances from the incoming speech signal and provides a reliable classification in any reasonable acoustic environment. This approach eliminates the necessity for the manual classification of training data and has the capability of being self-adapting to the background acoustic environment as well as to speech level variations. Thus the presented approach can be readily applied to on-line continuous speech classification without prior recognition.
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Date Issued: 1989
PURL: http://purl.flvc.org/fcla/dt/12246
Subject Headings: Speech synthesis, Speech processing systems
Format: Document (PDF)

Title: Development of methods for the immobilization of enzymes used in 9,11-secosteroid biosynthesis.
Creator: Chen, Ying, Florida Atlantic University, Kerr, Russell G.
Abstract/Description: 9,11-Secosteroids exhibit novel biological activity and interesting pharmacological properties. A biosynthetic study of 9,11-secogorgosterol and other novel 9,11-secosteroids using an enzyme extract from the gorgonian Pseudopterogorgia americana demonstrated that this system is an efficient catalyst for a wide range 9,11-secosteroid production. Two methods to recover the enzyme from 9,11-secosteroid synthesis have been developed: (1) membrane-enclosed enzymatic catalysis, which combines...
Show more9,11-Secosteroids exhibit novel biological activity and interesting pharmacological properties. A biosynthetic study of 9,11-secogorgosterol and other novel 9,11-secosteroids using an enzyme extract from the gorgonian Pseudopterogorgia americana demonstrated that this system is an efficient catalyst for a wide range 9,11-secosteroid production. Two methods to recover the enzyme from 9,11-secosteroid synthesis have been developed: (1) membrane-enclosed enzymatic catalysis, which combines certain of the advantages of soluble enzymes and immobilized enzymes, shows high activity, simple recovery and at least 5 cycles or 23 days; (2) covalently bonded enzyme-agarose gel, attached by cyanogen bromide via the amino groups of enzymes, show 80% activity of free enzymes and at least 7 cycles or 46 days. Based on stability and kinetic studies of these immobilized enzymes in 9,11-secosteroid synthesis, a continuous flow column reactor for scale-up of 9,11-secosteroid production has been developed with great efficiency, which represents the first enzymatic production of a bioactive compound from a marine invertebrate on a large scale.
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Date Issued: 1998
PURL: http://purl.flvc.org/fcla/dt/15521
Subject Headings: Octocorallia, Enzymes--Synthesis, Steroids
Format: Document (PDF)

Title: Biosynthesis and enzymology of secosteroids from Pseudopterogorgia americana.
Creator: Head, Kevin, Florida Atlantic University, Kerr, Russell G.
Abstract/Description: 9,11-Secosteroids are biologically active secondary metabolites from the marine invertebrate, Pseudopterogorgia americana. They are produced in vitro through an incubation of the steroid substrate with a cell-free extract of P. americana containing the necessary enzymes. Further optimization of this incubation was attempted through adjustment of incubation reagents and cofactors. The enzymes responsible for secosteroid production were partially purified through chromatography in an effort to...
Show more9,11-Secosteroids are biologically active secondary metabolites from the marine invertebrate, Pseudopterogorgia americana. They are produced in vitro through an incubation of the steroid substrate with a cell-free extract of P. americana containing the necessary enzymes. Further optimization of this incubation was attempted through adjustment of incubation reagents and cofactors. The enzymes responsible for secosteroid production were partially purified through chromatography in an effort to isolate and purify these enzymes. Finally, experiments with radiolabeled gorgosterol led to the elucidation and isolation of a key secosteroid precursor, 9,11-dihydroxygorgosterol.
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Date Issued: 1999
PURL: http://purl.flvc.org/fcla/dt/15711
Subject Headings: Alcyonacea, Enzymes--Synthesis, Sterols
Format: Document (PDF)

Title: An efficient preparation of beta-mercaptopyruvic acid, a putative intermediate in ecteinascidin biosynthesis.
Creator: Fawehinmi, Hafusat Abosede, Florida Atlantic University, Kerr, Russell G.
Abstract/Description: The ecteinascidins are a family of marine derived alkaloids with potent antitumor activity. Ecteinascidins 743 and 729 are the prime targets due to their superior antitumor activity. beta-Mercaptopyruvic acid is a proposed intermediate in the biosynthesis of ecteinascidins 743/729. A novel synthesis of beta-mercaptopyruvic acid using an enzymatic system was achieved. This was accomplished by trapping the equilibrium between beta-mercaptopyruvic acid and 2,5-dihydroxy-1,4-dithiane-2,5...
Show moreThe ecteinascidins are a family of marine derived alkaloids with potent antitumor activity. Ecteinascidins 743 and 729 are the prime targets due to their superior antitumor activity. beta-Mercaptopyruvic acid is a proposed intermediate in the biosynthesis of ecteinascidins 743/729. A novel synthesis of beta-mercaptopyruvic acid using an enzymatic system was achieved. This was accomplished by trapping the equilibrium between beta-mercaptopyruvic acid and 2,5-dihydroxy-1,4-dithiane-2,5-dicarboxylate using oxidative deamination of cysteine by amino acid oxidase.
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Date Issued: 1999
PURL: http://purl.flvc.org/fcla/dt/15725
Subject Headings: Tunicata, Pyruvic acid--Synthesis
Format: Document (PDF)

Title: Synthesis and coordination chemistry of the 1,3-bis(2-pyridylimino)benz(f)isoindoline ligand.
Creator: Maehlmann, William Pierre, Florida Atlantic University, Baird, Donald M.
Abstract/Description: Transition metal complexes of the mononucleating 1,3-bis(pyridylimino)isoindoline ligand (BAII) have been useful as redox catalysts and as models for naturally occurring metal centers. The redox properties of binuclear 1,3,5,7-tetra(pyridylimino)benzodipyrrole (TAII) complexes have also been investigated. Attempts to prepare 1,3,6,8-tetra(2-(4-methylpyridyl)imino)naphthodipyrrole (NTAII) using calcium chloride catalysis and solid fusion will be discussed. Divalent Cu, Ni, Zn, and Pd complexes...
Show moreTransition metal complexes of the mononucleating 1,3-bis(pyridylimino)isoindoline ligand (BAII) have been useful as redox catalysts and as models for naturally occurring metal centers. The redox properties of binuclear 1,3,5,7-tetra(pyridylimino)benzodipyrrole (TAII) complexes have also been investigated. Attempts to prepare 1,3,6,8-tetra(2-(4-methylpyridyl)imino)naphthodipyrrole (NTAII) using calcium chloride catalysis and solid fusion will be discussed. Divalent Cu, Ni, Zn, and Pd complexes of the mononucleating 1,3-bis(pyridylimino)benz(f)isoindoline ligand (NBAII) were prepared and the crystal structure of Cu(II)OAc(NBAII) is discussed. It is believed that the dimolybdenum NBAII complex has also been prepared. The NBAII complexes were characterized using NMR, IR, and UV-visible spectroscopy.
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Date Issued: 1994
PURL: http://purl.flvc.org/fcla/dt/15082
Subject Headings: Ligands--Synthesis, Coordination compounds
Format: Document (PDF)

Title: Studies towards a catalytic asymmetric isomerization of manganese complexed alkynes to allenes using chiral bases.
Creator: He, Chang., Charles E. Schmidt College of Science, Department of Chemistry and Biochemistry
Abstract/Description: The conversion of alkynyl carbonyls to allenyl carbonyls via manganese mediated coordination followed by a base-catalyzed isomerization was carried out using a range of chiral and achiral amine bases. Chiral amidine and chiral DBU derivatives were synthesized to carry out the isomerization enantioselectively. We employed HPLC equipped with a chiral column to determine the enantiomeric excess. We also proved that the mechanism of that the manganese-coordinated alkyne/allene rearrangement...
Show moreThe conversion of alkynyl carbonyls to allenyl carbonyls via manganese mediated coordination followed by a base-catalyzed isomerization was carried out using a range of chiral and achiral amine bases. Chiral amidine and chiral DBU derivatives were synthesized to carry out the isomerization enantioselectively. We employed HPLC equipped with a chiral column to determine the enantiomeric excess. We also proved that the mechanism of that the manganese-coordinated alkyne/allene rearrangement reaction involved an intermediate cumenolate. It was also confirmed that amine base with pKa lower than that of DBU (pKa = 13.6) would not carry out the isomerization. Alkoxy base were also used in isomerization and the mechanism was also investigated.
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Date Issued: 2009
PURL: http://purl.flvc.org/FAU/192983
Subject Headings: Enzyme kinetics, Organometallic compounds, Synthesis, Asymmetric synthesis, Methathesis (Chemistry), Carbonyl compounds, Synthesis
Format: Document (PDF)

Title: Halosulfites as a leaving groups in organic synthesis.
Creator: Kissner, William, Dragojlovic, Veljko
Date Issued: 2013-04-05
PURL: http://purl.flvc.org/fcla/dt/3361103
Subject Headings: Organic compounds--Synthesis, Substitution reactions
Format: Document (PDF)

Title: Chemoenzymatic synthesis of 9,11-secosteroids using an enzyme extract from a marine coral.
Creator: Rodriguez, Lesbeth Caridad., Florida Atlantic University, Kerr, Russell G.
Abstract/Description: 9,11-Secogorgosterol, a secondary metabolite from the gorgonian Pseudopterogorgia americana, exhibits inhibitory activity against protein kinase C, and potent anti-proliferative and anti-inflammatory activity. An efficient method for the production of 9,11-secogorgosterol has been developed and optimized using an enzyme extract from the gorgonian P. americana. The gorgonian also produces two other 9,11-secosteroids which have marked differences in their side chains and nuclei, which suggested...
Show more9,11-Secogorgosterol, a secondary metabolite from the gorgonian Pseudopterogorgia americana, exhibits inhibitory activity against protein kinase C, and potent anti-proliferative and anti-inflammatory activity. An efficient method for the production of 9,11-secogorgosterol has been developed and optimized using an enzyme extract from the gorgonian P. americana. The gorgonian also produces two other 9,11-secosteroids which have marked differences in their side chains and nuclei, which suggested that the enzymes responsible for their production were likely relatively nonspecific. Novel 9,11-secosteroids have been synthesized using the enzyme extract from the gorgonian.
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Date Issued: 1997
PURL: http://purl.flvc.org/fcla/dt/15431
Subject Headings: Steroids, Enzymes--Synthesis, Alcyonacea, Corals
Format: Document (PDF)

Title: Biophysical characterization of bioactive peptide amphiphiles.
Creator: Fishel, Ayala, Florida Atlantic University, Fields, Gregg B.
Abstract/Description: In this present work we have examined the biophysical characterization of two peptides. One alpha-helical (SPARC) and the other triple-helical (collagen). We have compared the effect of lipidation on stabilizing of the alpha-helical and triple-helical peptides. For the first peptide, amino acids from the angiogenesis-inducing region of SPARC were incorporated into alpha-helical peptide sequence. A Tyr was placed between the alpha-helical sequence and the peptide to provide a chromophore; Lys...
Show moreIn this present work we have examined the biophysical characterization of two peptides. One alpha-helical (SPARC) and the other triple-helical (collagen). We have compared the effect of lipidation on stabilizing of the alpha-helical and triple-helical peptides. For the first peptide, amino acids from the angiogenesis-inducing region of SPARC were incorporated into alpha-helical peptide sequence. A Tyr was placed between the alpha-helical sequence and the peptide to provide a chromophore; Lys-Ala-Glu-Ile-Glu-Ala-Leu-Lys-Ala-Glu-Ile-Glu-Ala-Leu-Lys-Ala-Tyr-Lys-His-Gly-Lys-NH 2 was the final sequence. For the second peptide, the sequence chosen to mimic the alpha2beta1 integrin binding site in type I collagen was (Gly-Pro-Hyp)4-Gly-Pro-Ala-Gly-Lys-Asp-Gly-Glu-Ala-Gly-Ala-Gln-(Gly-Pro-Hyp) 4-NH2. Next, each peptide was lipidated with a C-16 acid and was biophysically characterized to determine physiological compatibility. Techniques used included circular dichroism spectroscopy, gel electrophoresis, and Fourier transform infrared spectroscopy. Lastly, one of the peptide amphiphiles was examined as a biomaterial modifier.
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Date Issued: 2000
PURL: http://purl.flvc.org/fcla/dt/15780
Subject Headings: Peptides--Synthesis, Lipids, Bioactive compounds
Format: Document (PDF)

Title: Theoretical studies of the mechanism of the Wittig olefination reaction.
Creator: Restrepo, Albeiro A., Florida Atlantic University, Mari, Frank
Abstract/Description: The results we have obtained indicate that the common procedure of utilizing of the mythical Wittig half-reaction to theoretically describe the mechanism of the Wittig olefination reaction does not give consistent results when electron correlation is taken into account in the model hamiltonian. We propose that the reaction of Me3P=CH2 with formaldehyde is the smallest system that can be used to properly model the Wittig olefination reaction. The best compromise between accuracy and...
Show moreThe results we have obtained indicate that the common procedure of utilizing of the mythical Wittig half-reaction to theoretically describe the mechanism of the Wittig olefination reaction does not give consistent results when electron correlation is taken into account in the model hamiltonian. We propose that the reaction of Me3P=CH2 with formaldehyde is the smallest system that can be used to properly model the Wittig olefination reaction. The best compromise between accuracy and computational expense is to compute the molecular geometries with the HF/6-31G* methodology and the energy at the MP2/6-31G*/HF-6-31G* level. We applied the methodology that we have developed to the study of reaction of a series of stabilized, semistabilized and unstabilized ylides with acetaldehyde.
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Date Issued: 1997
PURL: http://purl.flvc.org/fcla/dt/15468
Subject Headings: Wittig reaction, Organic compounds--Synthesis
Format: Document (PDF)

Title: The biosynthetic production of marine-derived anti-tumor ecteinascidins and the aquaculture of the marine tunicate Ecteinascidia turbinata.
Creator: Krenisky, Joann Mary, Florida Atlantic University, Kerr, Russell G., Charles E. Schmidt College of Science, Department of Chemistry and Biochemistry
Abstract/Description: A family of tetrahydroisoquinoline alkaloids, the ecteinascidins, are a group of biologically active secondary metabolites produced by the marine tunicate Ecteinascidia turbinata. Ecteinascidins have shown in vivo anti-tumor activity against P388 lymphoma, B16 melanoma, M5076 ovarian sarcoma, Lewis lung carcinoma, and LX-1 human lung and MX-1 human mammary carcinoma xenografts in laboratory mice. Because ecteinascidins are produced in low yields, 1x10^-4%, supply for clinical development is a...
Show moreA family of tetrahydroisoquinoline alkaloids, the ecteinascidins, are a group of biologically active secondary metabolites produced by the marine tunicate Ecteinascidia turbinata. Ecteinascidins have shown in vivo anti-tumor activity against P388 lymphoma, B16 melanoma, M5076 ovarian sarcoma, Lewis lung carcinoma, and LX-1 human lung and MX-1 human mammary carcinoma xenografts in laboratory mice. Because ecteinascidins are produced in low yields, 1x10^-4%, supply for clinical development is a significant problem. The ultimate goal of this study is to develop an enzyme-based synthesis of the ecteinascidins. In this regard, the biosynthesis of these alkaloids has been investigated. Optimal conditions for in vitro ecteinascidin biosynthesis were found. The origin of the C22-C1 two-carbon unit was identified as pyruvate and the tyrosine and DOPA diketopiperazines were identified as key intermediates. Methods were developed for an in-the-sea aquaculture of the colonal marine ascidian Ecteinascidia turbinata.
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Date Issued: 1997
PURL: http://purl.flvc.org/fcla/dt/15454
Subject Headings: Sea squirts, Tetrahydroisoquinolines, Alkaloids--Synthesis
Format: Document (PDF)

Title: An investigation of the fatty acid synthase of Gymnodinium breve, a marine dinoflagellate.
Creator: Borrone, James William., Florida Atlantic University, Kerr, Russell G.
Abstract/Description: Gymnodinium breve is responsible for toxic blooms causing epizootics and, in humans, neurotoxic shellfish poisoning. Toxicity is from a family of polyketides known as brevetoxins. Proposed biosynthetic mechanisms of brevetoxin production are analogous to fatty acid biosynthesis. As part of an investigation of brevetoxin production, the fatty acid synthase from Gymnodinium breve was characterized. Cell free extracts of G. breve incorporated [3H]-acetate and [3H]-acetyl-CoA into palmitate with...
Show moreGymnodinium breve is responsible for toxic blooms causing epizootics and, in humans, neurotoxic shellfish poisoning. Toxicity is from a family of polyketides known as brevetoxins. Proposed biosynthetic mechanisms of brevetoxin production are analogous to fatty acid biosynthesis. As part of an investigation of brevetoxin production, the fatty acid synthase from Gymnodinium breve was characterized. Cell free extracts of G. breve incorporated [3H]-acetate and [3H]-acetyl-CoA into palmitate with lesser incorporation into stearate, myristate, and laurate. Fatty acid synthase activity was associated with the chloroplast, appeared to be composed of membrane-associated and soluble components, and was not completely inhibited by cerulenin. These results suggests that G. breve possesses a Type II fatty acid synthase similar in organization to those found in other photosynthetic organisms. Isolation of the enzymes, on both an enzymatic and genomic level, were hindered by low amounts G. breve cells and bacteria present within the cultures.
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Date Issued: 2000
PURL: http://purl.flvc.org/fcla/dt/12711
Subject Headings: Ptychodiscus brevis, Fatty acids--Synthesis
Format: Document (PDF)

Title: Isolation of the fatty acid synthetase from the marine invertebrate Bugula neritina.
Creator: Koh, Francis H., Florida Atlantic University, Kerr, Russell G., Charles E. Schmidt College of Science, Department of Chemistry and Biochemistry
Abstract/Description: The fatty acid synthetase (FAS) from the marine invertebrate Bugula neritina was isolated using cold ethanol precipitation followed by the sequence of G-100 and G-200 size exclusion columns. Native gel analysis indicates the isolation of the FAS and the elution volume from the G-100 column suggests the FAS to be ~282kd. One band with a molecular weight of 66 kDa appeared on the SDS gel of the G-200 sample (F17-30) that eluted at 52.5 mL. The G-200 sample that eluted at 19.2 mL (F1-6)...
Show moreThe fatty acid synthetase (FAS) from the marine invertebrate Bugula neritina was isolated using cold ethanol precipitation followed by the sequence of G-100 and G-200 size exclusion columns. Native gel analysis indicates the isolation of the FAS and the elution volume from the G-100 column suggests the FAS to be ~282kd. One band with a molecular weight of 66 kDa appeared on the SDS gel of the G-200 sample (F17-30) that eluted at 52.5 mL. The G-200 sample that eluted at 19.2 mL (F1-6) displayed two predominant bands on the SDS gel corresponding to molecular weights 66 kDa and 97 kDa. Both F1-6 and F17-30 showed FAS activity displaying de novo production of myristic and palmitic acids. From the sequence of purification starting from the cell-free extract (CFE) to the F17-30 sample, a 240 fold increase in specific activity was observed. The Type II FAS experiments showed no substantial evidence of activity, namely of the beta-Hydroxybutyryl acyl-dehydrase and the enoyl reductase enzymes.
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Date Issued: 1998
PURL: http://purl.flvc.org/fcla/dt/15546
Subject Headings: Fatty acids--Synthesis, Marine pharmacology, Bryozoa
Format: Document (PDF)

Title: Characterization of SNAG-zinc finger protein (ZFP) transcription factors.
Creator: Chiang, Cindy Chung-Yue., Charles E. Schmidt College of Science, Department of Biological Sciences
Abstract/Description: Transcriptional regulation is an important area of research due to the fact that it leads to gene expression. Transcription factors associated with the regulation can either be activators or repressors of target genes, acting directly or with the aid of other factors. A majority of transcriptional repressors are zinc finger proteins (ZFPs) which bind to specific DNA sequences. The Snail/Gfi (SNAG) domain family, with members such as Slug, Smuc, Snail, and Scratch, are transcriptional...
Show moreTranscriptional regulation is an important area of research due to the fact that it leads to gene expression. Transcription factors associated with the regulation can either be activators or repressors of target genes, acting directly or with the aid of other factors. A majority of transcriptional repressors are zinc finger proteins (ZFPs) which bind to specific DNA sequences. The Snail/Gfi (SNAG) domain family, with members such as Slug, Smuc, Snail, and Scratch, are transcriptional repressors shown to play a role in various diseases such as cancer. The SNAG transcription factors contain a conserved SNAG repression domain and DNA binding domain zinc fingers. The specific DNA sequences to which each SNAG-ZFP binds, as well as a general consensus -TGCACCTGTCCGA, have been determined. Also, putative protein-protein interactions in which the Slug domain participates has been identified via binding assays. All these results contribute to better understanding of SNAG-ZFP functions.
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Date Issued: 2009
PURL: http://purl.flvc.org/FAU/186676
Subject Headings: Zinc-finger proteins, Synthesis, Metalloproteins, Synthesis, Genetic transcription, Regulation, Cellular signal transduction, Gene expression
Format: Document (PDF)

Title: A comprehensive study of mammalian SNAG transcription family members.
Creator: Chiang, Cindy Chung-Yue., Charles E. Schmidt College of Science, Department of Biological Sciences
Abstract/Description: Transcriptional regulation by the family of SNAG (Snail/Gfi-1) zinc fingers has been shown to play a role in various developmental states and diseases. These transcriptional repressors have function in both DNA- and protein-binding, allowing for multiple interactions by a single family member. This work aims to characterize the SNAG members Slug, Smuc, Snail, Scratch, Gfi-1, Gfi-1B, and IA-1 in terms of both DNA-protein and protein-protein interactions. The specific DNA sequences to which the...
Show moreTranscriptional regulation by the family of SNAG (Snail/Gfi-1) zinc fingers has been shown to play a role in various developmental states and diseases. These transcriptional repressors have function in both DNA- and protein-binding, allowing for multiple interactions by a single family member. This work aims to characterize the SNAG members Slug, Smuc, Snail, Scratch, Gfi-1, Gfi-1B, and IA-1 in terms of both DNA-protein and protein-protein interactions. The specific DNA sequences to which the zinc finger regions bind were determined for each member, and a general consensus of TGCACCTGTCCGA, was developed for four of the members. Via these studies, we also reveal thebinding affinities of E-box (CANNTG) sequences to the members, since this core is found for multiple members' binding sites. Additionally, protein-protein interactions of SNAG members to other biological molecules were investigated. The Slug domain and Scratch domain have unknown function, yet through yeast two-hybrid screening, we were able to determine protein interaction partners for them as well as for other full length SNAG members. These protein-interacting partners have suggested function as corepressors during transcriptional repression. The comprehensive information determined from these studies allow for a better understanding of the functional relationship between SNAG-ZFPs and other genes. The collected data not only creates a new profile for each member investigated, but it also allows for further studies to be initiated from the results.
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Date Issued: 2012
PURL: http://purl.flvc.org/fcla/dt/3342041
Subject Headings: Cellular signal transduction, Zinc-finger proteins, Synthesis, Metalloproteins, Synthesis, Genetic transcription, Regulation
Format: Document (PDF)

FAU Theses and Dissertations (51)	+ -
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Synthesis (18)	+ -
Genetic transcription (8)	+ -
Cellular signal transduction (7)	+ -
Gene expression (7)	+ -
Regulation (7)	+ -

Zinc-finger proteins (7)	+ -
Marine pharmacology (6)	+ -
Organic compounds--Synthesis (6)	+ -
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Drosophila melanogaster (3)	+ -
Enzymes--Synthesis (3)	+ -
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Electronic Thesis or Dissertation (51)	+ -
article (4)	+ -
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Florida Atlantic University (35)	+ -
Charles E. Schmidt College of Science (31)	+ -
Department of Chemistry and Biochemistry (23)	+ -
Kerr, Russell G. (15)	+ -
Department of Biological Sciences (8)	+ -

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