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You searched for +publisher:"Florida International University" +contributor:("Anthony P. DeCaprio"). Showing records 1 – 3 of 3 total matches.

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Florida International University

1. Birudukota, Nagaraju. Design and synthesis of novel Azasteroids and Pseudoazulenyl nitrones.

Degree: PhD, Chemistry, 2016, Florida International University

Steroids are one of the essential classes of bioactive compounds and are involved in many biological functions which include their role as signaling compounds, the alteration of membrane fluidity and the regulation of a variety of metabolic processes. In order to identify novel compounds with beneficial pharmacological action, the synthesis of modified steroids is gaining much attention in recent years. Among those analogs, azasteroids are one of the most important classes which display a variety of biological activities, often free from undesirable side effects. The challenges in the synthesis of steroids, particularly azasteroids, and the potential of azasteroids as novel drugs has prompted numerous investigations in this field. The synthetic methods leading to steroidal derivatives (azasteroids) with one or more nitrogen atoms are very limited. Generally, oxidative cleavage of the steroidal rings is needed to introduce nitrogen atom(s) in order to synthesize azasteroids. In the first part of this dissertation, explorations into the synthetic methods needed for making a new steroidal A-ring or seco A-ring on a tricyclic benz[e]indenedione (a dimer compound obtained in connection with continued work on the study of anhydrobases of the isoxazole series) were pursued. In this process, a series of three tricyclic hydrazone compounds have been designed and synthesized to mimic the tetracyclic rigid core structure of azasteroids. We are eager to ascertain if these compounds possesses any interesting biological properties. In continued research on the synthesis of azulenyl and pseudoazulenyl nitrones, (to target ROS generation at the site of mitochondria), the second part of this research was aimed at the synthesis of cationic pseudoazulenyl nitrones with mitochondriotropic properties. Several pseudoazulenyl nitrone derivatives were synthesized using the natural compound valtrate, obtained from the roots of Centranthus ruber. Unfortunately, the attempts made to convert these compounds into the corresponding cationic pseudoazulenyl nitrones failed. However, an interesting pseudoazulenyl dinitrone molecule bearing an imidazole group was prepared. Also, a pseudoazulenyl mono nitrone compound with an electron donating group was synthesized by leaving a highly reactive aldehyde functionality intact for further use in synthetic study. Advisors/Committee Members: David A. Becker, Stanislaw F. Wnuk, Kevin O'Shea, Anthony P. DeCaprio, Richard A. Bone.

Subjects/Keywords: Synthesis; Azasteroids; Azasteroidal mimics; Azulenes; Azulenyl nitrones; Pseudoazulenes; Pseudoazulenyl nitrones; Biochemistry; Chemistry; Organic Chemistry

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APA (6th Edition):

Birudukota, N. (2016). Design and synthesis of novel Azasteroids and Pseudoazulenyl nitrones. (Doctoral Dissertation). Florida International University. Retrieved from https://digitalcommons.fiu.edu/etd/3262 ; 10.25148/etd.FIDC001734 ; FIDC001734

Chicago Manual of Style (16th Edition):

Birudukota, Nagaraju. “Design and synthesis of novel Azasteroids and Pseudoazulenyl nitrones.” 2016. Doctoral Dissertation, Florida International University. Accessed September 22, 2020. https://digitalcommons.fiu.edu/etd/3262 ; 10.25148/etd.FIDC001734 ; FIDC001734.

MLA Handbook (7th Edition):

Birudukota, Nagaraju. “Design and synthesis of novel Azasteroids and Pseudoazulenyl nitrones.” 2016. Web. 22 Sep 2020.

Vancouver:

Birudukota N. Design and synthesis of novel Azasteroids and Pseudoazulenyl nitrones. [Internet] [Doctoral dissertation]. Florida International University; 2016. [cited 2020 Sep 22]. Available from: https://digitalcommons.fiu.edu/etd/3262 ; 10.25148/etd.FIDC001734 ; FIDC001734.

Council of Science Editors:

Birudukota N. Design and synthesis of novel Azasteroids and Pseudoazulenyl nitrones. [Doctoral Dissertation]. Florida International University; 2016. Available from: https://digitalcommons.fiu.edu/etd/3262 ; 10.25148/etd.FIDC001734 ; FIDC001734


Florida International University

2. Rayala, Ramanjaneyulu. Design and Synthesis of Novel Nucleoside Analogues: Oxidative and Reductive Approaches toward Synthesis of 2'-Fluoro Pyrimidine Nucleosides.

Degree: PhD, Chemistry, 2015, Florida International University

Fluorinated nucleosides, especially the analogues with fluorine atom(s) in the ribose ring, have been known to exert potent biological activities. The first part of this dissertation was aimed at developing oxidative desulfurization-fluorination and reductive desulfonylation-fluorination methodologies toward the synthesis of 2'-mono and/or 2',2'-difluoro pyrimidine nucleosides from the corresponding 2'-arylthiopyrimidine precursors. Novel oxidative desulfurization-difluorination methodology was developed for the synthesis of α,α-difluorinted esters from the corresponding α-arylthio esters, wherein the arylthio group is present on a secondary internal carbon. For the reductive desulfonylation studies, cyclic voltammetry was utilized to measure the reduction potentials at which the sulfone moiety of substrates can be cleaved. The 5-bromo pyrimidine nucleosides and 8-bromo purine nucleosides act as crucial intermediates in various synthetic transformations. The second part of the present dissertation was designed to develop a novel bromination methodology using 1,3-dibromo-5,5-dimethylhydantoin (DBH). Various protected and deprotected pyrimidine and purine nucleosides were converted to their respective C5 and C8 brominated counterparts using DBH. The effect of Lewis acids, solvents, and temperature on the efficiency of bromination was studied. Also, N-bromosuccinimide (NBS) or DBH offered a convenient access to 8-bromotoyocamycin and 8-bromosangivamycin. Third part of this research work focuses on the design and synthesis of 6-N-benzylated derivatives of 7-deazapurine nucleoside antibiotics, such as tubercidin, sangivamycin and toyocamycin. Target molecules were synthesized by two methods. First method involves treatment of 7-deazapurine substrates with benzylbromide followed by dimethylamine-promoted Dimroth rearrangement. The second method employs fluoro-diazotization followed by SNAr displacement of the 6-fluoro group by a benzylamine. The 6-N-benzylated 7-deazapurine nucleosides showed type-specific inhibition of cancer cell proliferation at micromolar concentrations and weak inhibition of human equilibrative nucleoside transport protein (hENT1). In the fourth part of this dissertation, syntheses of C7 or C8 modified 7-deazapurine nucleosides, which might exhibit fluorescent properties, were undertaken. 8-Azidotoyocamycin was synthesized by treatment of 8-bromotoyocamycin with sodium azide. Strain promoted click chemistry of 8-azidotoyocamycin with cyclooctynes gave the corresponding 8-triazolyl derivatives. Alternatively, 7-benzotriazolyl tubercidin was synthesized by iodine catalyzed CH arylation of tubercidin with benzotriazole. Advisors/Committee Members: Stanislaw F. Wnuk, Kathleen S. Rein, David A. Becker, Anthony P. DeCaprio, Salvatore D. Lepore.

Subjects/Keywords: Fluorination; Desulfurization; Desulfonylation; Pyrimidines; Purines; 7-Deazapurines; DBH; Click Chemistry; C-H Functionalization; One Electron Oxidation; Carbohydrates; Heterocyclic Compounds; Nucleic Acids, Nucleotides, and Nucleosides

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APA · Chicago · MLA · Vancouver · CSE | Export to Zotero / EndNote / Reference Manager

APA (6th Edition):

Rayala, R. (2015). Design and Synthesis of Novel Nucleoside Analogues: Oxidative and Reductive Approaches toward Synthesis of 2'-Fluoro Pyrimidine Nucleosides. (Doctoral Dissertation). Florida International University. Retrieved from https://digitalcommons.fiu.edu/etd/2172 ; 10.25148/etd.FIDC000129 ; FIDC000129

Chicago Manual of Style (16th Edition):

Rayala, Ramanjaneyulu. “Design and Synthesis of Novel Nucleoside Analogues: Oxidative and Reductive Approaches toward Synthesis of 2'-Fluoro Pyrimidine Nucleosides.” 2015. Doctoral Dissertation, Florida International University. Accessed September 22, 2020. https://digitalcommons.fiu.edu/etd/2172 ; 10.25148/etd.FIDC000129 ; FIDC000129.

MLA Handbook (7th Edition):

Rayala, Ramanjaneyulu. “Design and Synthesis of Novel Nucleoside Analogues: Oxidative and Reductive Approaches toward Synthesis of 2'-Fluoro Pyrimidine Nucleosides.” 2015. Web. 22 Sep 2020.

Vancouver:

Rayala R. Design and Synthesis of Novel Nucleoside Analogues: Oxidative and Reductive Approaches toward Synthesis of 2'-Fluoro Pyrimidine Nucleosides. [Internet] [Doctoral dissertation]. Florida International University; 2015. [cited 2020 Sep 22]. Available from: https://digitalcommons.fiu.edu/etd/2172 ; 10.25148/etd.FIDC000129 ; FIDC000129.

Council of Science Editors:

Rayala R. Design and Synthesis of Novel Nucleoside Analogues: Oxidative and Reductive Approaches toward Synthesis of 2'-Fluoro Pyrimidine Nucleosides. [Doctoral Dissertation]. Florida International University; 2015. Available from: https://digitalcommons.fiu.edu/etd/2172 ; 10.25148/etd.FIDC000129 ; FIDC000129


Florida International University

3. Gwak, Seongshin. Comprehensive Analysis of Emerging New Psychoactive Substances by Ion Mobility Spectrometry and Mass Spectrometry.

Degree: PhD, Chemistry, 2015, Florida International University

In the new era of drug abuse, the proliferation of new psychoactive substances (NPS), commonly referred to as designer drugs or legal highs, has been a global concern. These substances are produced to circumvent current legislation for controlled substances with minor modifications in their chemical structure. Although many efforts have been made previously, the characterization of such substances are still challenging because of (1) the continual emergence of newly identified substances, (2) the lack of a universal screening test for NPS that are structurally similar to each other, and (3) the complex and time-consuming chromatographic techniques currently used. Therefore, it is necessary to develop novel analytical methods that can be readily adapted by forensic laboratories to overcome these challenges. In this dissertation, various analytical techniques have been evaluated for qualitative analysis of these emerging NPS. For rapid screening purposes, a commercial ion mobility spectrometry with a 63Ni ion source (63Ni-IMS) and also direct analysis in real time coupled to a quadrupole time-of-flight mass spectrometer (DART-QTOF-MS) were investigated first. The results showed that rapid detection by 63Ni-IMS and identification by DART-QTOF-MS can be achieved with sub-nanogram detection capability and high speed total analysis time less than two minutes. In recent developments of gas chromatography mass spectrometry (GC-MS), gas chromatography (GC) has been coupled to state-of-the-art mass spectrometers, including triple quadrupole (MS/MS) and quadrupole time-of-flight (QTOF). It was revealed that the application of GC-MS/MS and GC-QTOF facilitates the unambiguous identification of emerging NPS with a chemical ionization (CI) source. In addition, constitutional isomers of NPS were differentiated with the capabilities of product ion scan and multiple reaction monitoring (MRM) modes. Finally, the coupling of IMS with a mass spectrometer (IMS-MS) was investigated as an alternative confirmatory technique. With the development of an optimal solvent system in the electrospray ionization (ESI) process, the rapid analysis and identification of synthetic cathinone was successfully achieved less than five minutes. As a proof-of-concept, seized drugs samples provided by a local forensic laboratory were analyzed using these developed methods by various analytical techniques. The results from these seized samples are also presented in this evaluation. Advisors/Committee Members: José R. Almirall, Anthony P. DeCaprio, Fenfei Leng, Wenzhi Li, Bruce R. McCord.

Subjects/Keywords: New Psychoactive Substances; Ion Mobility Spectrometry; Mass Spectrometry; Analytical Chemistry

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APA · Chicago · MLA · Vancouver · CSE | Export to Zotero / EndNote / Reference Manager

APA (6th Edition):

Gwak, S. (2015). Comprehensive Analysis of Emerging New Psychoactive Substances by Ion Mobility Spectrometry and Mass Spectrometry. (Doctoral Dissertation). Florida International University. Retrieved from https://digitalcommons.fiu.edu/etd/2291 ; 10.25148/etd.FIDC000157 ; FIDC000157

Chicago Manual of Style (16th Edition):

Gwak, Seongshin. “Comprehensive Analysis of Emerging New Psychoactive Substances by Ion Mobility Spectrometry and Mass Spectrometry.” 2015. Doctoral Dissertation, Florida International University. Accessed September 22, 2020. https://digitalcommons.fiu.edu/etd/2291 ; 10.25148/etd.FIDC000157 ; FIDC000157.

MLA Handbook (7th Edition):

Gwak, Seongshin. “Comprehensive Analysis of Emerging New Psychoactive Substances by Ion Mobility Spectrometry and Mass Spectrometry.” 2015. Web. 22 Sep 2020.

Vancouver:

Gwak S. Comprehensive Analysis of Emerging New Psychoactive Substances by Ion Mobility Spectrometry and Mass Spectrometry. [Internet] [Doctoral dissertation]. Florida International University; 2015. [cited 2020 Sep 22]. Available from: https://digitalcommons.fiu.edu/etd/2291 ; 10.25148/etd.FIDC000157 ; FIDC000157.

Council of Science Editors:

Gwak S. Comprehensive Analysis of Emerging New Psychoactive Substances by Ion Mobility Spectrometry and Mass Spectrometry. [Doctoral Dissertation]. Florida International University; 2015. Available from: https://digitalcommons.fiu.edu/etd/2291 ; 10.25148/etd.FIDC000157 ; FIDC000157

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