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Full-Text Articles in Physical Sciences and Mathematics

Synthesis And Characterization Of Chitosan Derivatives Intended For Gene Delivery Applications, Alex M. Mcmullen Jan 2022

Synthesis And Characterization Of Chitosan Derivatives Intended For Gene Delivery Applications, Alex M. Mcmullen

MSU Graduate Theses

Chitosan has been studied as a non-viral vector capable of efficient gene delivery due to its favorable properties such as biodegradability, biocompatibility, and is non-toxic to mammalian cells. Incorporating electrostatic interactions in non-viral vectors enhance the vector permeability. This work focuses on two parts. Firstly, cationic chitosan derivatives were synthesized using quarternary ammonium and phosphonium groups. This was achieved by coupling carboxylic acid ligands with these quarternary groups to chitosan through an amide bond. The carboxylic acid ligands were synthesized from 4-methylbenzoic acid and either triethyl phosphine or triethyl amine. The ligand was then attached to chitosan through an amide …


Methodologies For Metal Functionalization Of Phosphorus Based Photopolymer Networks, Vanessa Béland Oct 2019

Methodologies For Metal Functionalization Of Phosphorus Based Photopolymer Networks, Vanessa Béland

Electronic Thesis and Dissertation Repository

Photopolymer networks with phosphonium cation, alkyl phosphine and olefin functionality were designed, synthesized and functionalized with metals by metathesis, coordination and hydrometallation reactions, respectively. The materials were strategically designed so that the metal functionalization step could be monitored and quantified. In some cases, this involved characterization by IR, NMR, or X-ray spectroscopic techniques, or by comparison to molecular analogues. It was found that by using a bi-functional photopolymer network, the material could be bi-metallized by orthogonal mechanisms. All metallized polymer networks were tested for their suitability as precursors to metal-containing ceramics. The polymers were pyrolyzed, and on analysis it was …


Synthesis, Characterization, And Applications Of Ammonium/Phosphonium Chitosan Derivatives For Investigative Dna Interactions, Quinton Kirk Wyatt Aug 2018

Synthesis, Characterization, And Applications Of Ammonium/Phosphonium Chitosan Derivatives For Investigative Dna Interactions, Quinton Kirk Wyatt

MSU Graduate Theses

Chitosan is examined as a non-viral vector capable of efficient gene delivery due to its favorable properties such as biodegradability, biocompatibility, and is non-toxic to mammalian cells. Cell modifications and vector permeability are enhanced in non-viral vectors that incorporate electrostatic interactions. This work synthesizes cationic (N+, P+) chitosan derivatives, to enhance electrostatic interactions towards nucleotides, using amide coupling agents EDC and HOBt. The final chitosan derivatives will bear cationic functional groups (N+, P+) with various alkyl groups (Me, Et, Pr, Ph) to examine their affinities to nucleotides and antifungal properties. mPEG grafted …


Facile Synthesis Of 1-Alkoxy-1h-Benzo- And 7-Azabenzotriazoles From Peptide Coupling Agents, Mechanistic Studies, And Synthetic Applications, Mahesh K. Lakshman, Manish K. Singh, Mukesh Kumar, Raghu Ram Chamala, Vijayender R. Yedulla, Domenick Wagner, Evan Leung, Lijia Yang, Asha Matin, Sadia Ahmad Aug 2014

Facile Synthesis Of 1-Alkoxy-1h-Benzo- And 7-Azabenzotriazoles From Peptide Coupling Agents, Mechanistic Studies, And Synthetic Applications, Mahesh K. Lakshman, Manish K. Singh, Mukesh Kumar, Raghu Ram Chamala, Vijayender R. Yedulla, Domenick Wagner, Evan Leung, Lijia Yang, Asha Matin, Sadia Ahmad

Publications and Research

(1H-Benzo[d][1,2,3]triazol-1-yloxy)tris(dimethylamino)phosphonium hexafluorophosphate (BOP), 1H-benzo[d][1,2,3]triazol-1-yl 4-methylbenzenesulfonate (Bt-OTs), and 3H-[1,2,3]triazolo[4,5-b]pyridine-3-yl 4-methylbenzenesulfonate (At-OTs) are classically utilized in peptide synthesis for amide-bond formation. However, a previously undescribed reaction of these compounds with alcohols in the presence of a base, leads to 1-alkoxy-1H-benzo- (Bt-OR) and 7-azabenzotriazoles (At-OR). Although BOP undergoes reactions with alcohols to furnish 1-alkoxy-1H-benzotriazoles, Bt-OTs proved to be superior. Both, primary and secondary alcohols undergo reaction under generally mild reaction conditions. Correspondingly, 1-alkoxy-1H-7-azabenzotriazoles were synthesized from At-OTs. Mechanistically, there are three pathways by which these peptide-coupling agents can react with alcohols. From 31P{1H}, [18O]-labeling, and other chemical experiments, phosphonium and tosylate derivatives of …


Cyclic Phosphonium Ionic Liquids, Sharon I. Lall-Ramnarine, Joshua A. Mukhlall, James F. Wishart, Robert R. Engel, Alicia R. Romeo, Masao Gohdo, Sharon Ramati, Marc B. Berman, Sophia N. Suarez Jan 2014

Cyclic Phosphonium Ionic Liquids, Sharon I. Lall-Ramnarine, Joshua A. Mukhlall, James F. Wishart, Robert R. Engel, Alicia R. Romeo, Masao Gohdo, Sharon Ramati, Marc B. Berman, Sophia N. Suarez

Publications and Research

Ionic liquids (ILs) incorporating cyclic phosphonium cations are a novel category of materials. We report here on the synthesis and characterization of four new cyclic phosphonium bis(trifluoromethylsulfonyl)amide ILs with aliphatic and aromatic pendant groups. In addition to the syntheses of these novel materials, we report on a comparison of their properties with their ammonium congeners. These exemplars are slightly less conductive and have slightly smaller self-diffusion coefficients than their cyclic ammonium congeners.