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CHEM450 Seminar Schedule
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PHAR 132, 3.35-4.30pm
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Practice datePresentation dateSpeakerAffiliationTitleAbstract (100-200 words)Zoom linkpasscode
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Friday, January 27, 2023Adam Albergraduate chemistry student, University of Oklahoma, B.S. in chemistry from St. John Fisher UniversityEnynal Derived Copper Carbene-Mediated 1,2-cis Furanosylations1,2-cis furanosides are found throughout many natural products, and carbohydrates in general are the most common motif found in natural products.1 Furanosides are sugars that have formed a five-membered ring. Cis-furanosides are those in which the group at the anomeric (C1) position is on the same face of the ring as the group on the adjacent C2 carbon. Furanosides in particular are found in the cell wall of many pathogenic microorganisms and plants and play crucial roles in disease progression and interaction with host immune systems.2-5 Most furanosylation strategies traditionally involved neighboring group participation6-9 which would often result in the formation of the 1,2-trans product. However, by harnessing the power of carbenes, the Sharma group has developed a heretofore undocumented catalytic 1,2-cis furanosylation strategy using Earth-abundant copper and unconventional enynal donors to initiate anomeric functionalization through activation of a long-range carbene.
Over the course of this presentation, we will discuss the history of carbohydrates, currently known furanosylation strategies, methods developed by the Sharma lab, and future directions proposed by the Sharma lab. Furanosides, particularly ribose and arabinose, were investigated as furanosyl donors. These novel donors are activated with simple, Earth-abundant copper catalysts to yield the stereoselective 1,2-cis furanoside products. The nature, structure, mechanism of reactivity, and more will be discussed further at length during the talk itself.
https://sjfc.zoom.us/rec/share/QrPMp-az8f-G5LMqPfpm_vqoxRAykphs5m-W2IwCOZqiHvZwQu0klIMYUwr7FW66.EJYtPFYHHGEOHiIVFv4y&GFt
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Thursday, January 26, 2023Friday, February 3, 2023Dr. Alexey IgnatchenkoAssociate Professor,
St. John Fisher University		Preparation of ketones by decarboxylative ketonization: mechanism, rates of elementary steps, reversibility and degenerate reactionsAn insight into the catalytic preparation of ketones from carboxylic acids by decarboxylative ketonization, its mechanism, and side reactions is offered. Catalytic decarboxylative ketonization of carboxylic acids is used for industrial preparation of ketones and for upgrading pyrolysis oil in renewable energy catalysis. The rate limiting elementary step of the catalytic mechanism on surface of metal oxide catalysts is the condensation of one molecule of surface carboxylate with another one which is enolized. Rate constants of individual steps of the reaction mechanism, enolization and decarboxylation with ZrO2 and TiO2 catalysts were measured and compared with the global reaction rate.
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Friday, February 10, 2023Dr. Brad KraftAssociate Professor,
St. John Fisher University		Chelation Equilibria and pi-Electron
Delocalization and in Organosilicon
Complexes of 1-Hydroxy-2-Pyridinone
and 2-Pyrithione		Chelation-induced pi-electron delocalization (pi-ED) within ligands may contribute to increased stability of metal complexes and improved utility in chemical and biological applications. Toward increasing our understanding of this phenomenon, families of organosilicon compounds, R3SiX, R2SiX2, and RSiX2Cl [R = alkyl, aryl; X = 1-oxo-2-pyridinone and 1-oxo-2-pyridinethione], and related derivatives have been examined. X-ray crystallographic analyses reveal a diversity of 4-, 5-, and 6-coordinate neutral complexes with ligands binding in bidentate and unprecedented k-O monodentate modes and of cationic complexes with bidentate ligands. In the neutral chelated pyridinone complexes, carbonyl groups are generally datively bonded to silicon. In the neutral chelated pyrithione complexes, examples spanning a continuum of datively bonded thione and datively bonded N-oxide groups are observed. In TBP complexes of pyrithione, the chelate effect is enhanced when sulfur is bonded in an equatorial vs. an axial position. Variable-temperature NMR spectroscopy reveals chelation equilibria in many complexes involving Si--O=C or Si--S=C bond dissociation and is influenced by solvent and sterics of the ancillary ligands.https://sjfc.zoom.us/rec/share/xIrN64REBEliNJsAqB-SAa54uana1rAo2SrcofpJ-ZrdHK-F8vRkLb9hOYyuXMPy.wRu-jlEyKDjOLQ5U%2wDNipK
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Friday, February 17, 2023Dr. Irene KimaruAssociate Professor,
St. John Fisher University		Development and Evaluation of New Amino Acid-Based Chiral Ionic Liquids for Potential Applications in Chiral AnalysisChiral ionic liquids (CILs) are popular for their potential applications in chiral analysis. CILs are a sub-class of ionic liquids, which possess either a chiral cation or anion, or both can be chiral. CILs derived from amino acids that are chiral, ‘green’, biocompatible and less toxic are desirable. The synthesis, characterization and evaluation of new amino acid-based ILs for was carried out. This included investigations of the potential use as; chiral solvents to study enantioselective interactions and chiral discrimination ability for enantiomers using fluorescence spectroscopy, as chiral selectors for high performance liquid chromatography (HPLC), and chiral stationary phases for gas chromatography (GC). New amino acid-based CILs were synthesized using an ion exchange reaction involving amino acid chlorides and lithium ion electrolytes. The resultants CILs were analyzed for purity using 1H and 13C NMR. Physical and chemical properties of the CILs were evaluated using thermal gravimetric analysis (TGA) to determine thermal stability, differential scanning calorimetry (DSC) to determine melting point and glass transition temperatures. The findings of this work over several years will be presented. https://sjfc.zoom.us/rec/share/I3OnJlGtPU5mhWqn6QMGyVQ2cMPY11qPz65tqHx1G_eUg49UlFZNkPzSt67tCeOm.edYPWHaHIERBKxYg@W2q65?=
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Friday, February 24, 2023Dr. Kevin CallahanAssociate Professor,
St. John Fisher University		Discussion of ongoing research projects in Dr. Callahan's labhttps://sjfc.zoom.us/rec/share/X5WU4dKb0sBR6GFU52OA4Fno2Ew5qtT2PeK-EgxpjEKxID6qdrSy-L9W6wUv92uB.NTYKgXw7QpejCIPp yWs*5Per
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Friday, March 3, 2023cancelledcancelledcancelled
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Thursday, March 16, 2023Dr. Ranga DiasResearch fellow at the Harvard University, assistant professor at the University of RochesterNear-ambient superconductivity in a N-doped lutetium hydrideThe importance of room temperature superconductors for solving the world energy crisis can't be emphasized enough. The next revolution in technology achieved through a wide use of room temperature superconductors will change the way we live on Earth and take care of our planet.
Our guest speaker, Dr. Ranga Dias will present his research results on high temperature superconductivity and magnetism. Dr. Dias was named by the Time magazine among 100 top most influential people in 2021. https://time.com/collection/time100-next-2021/5937727/ranga-dias/
Experiments on materials at extreme pressure and temperature conditions demonstrate how materials alter their properties in many fundamental ways. This field provides exciting opportunities for one to discover new materials, novel phenomena, and exotic states of matter that are not present at the ambient conditions. Dr. Dias' research efforts not only address fundamental understanding but are also directed towards utilizing high pressure and temperature conditions to understand chemical processes and interactions to synthesize novel advanced materials, such as high energy density materials, superhard solids, and quantum materials.
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Thursday, March 2, 2023Friday, March 17, 2023Olivia KampnichSenior chemistry major, St. John Fisher UniversityReaction of Rhenium and Ruthenium Tri(thiolate) Complexes with Unsaturated Hydrocarbons: Study of Mechanism and Noninnocent Nature of LigandThe oxidation of ruthenium and rhenium radial centered ligands via styrene/alkene addition has been studied in order to determine the non-innocent nature of the ligand and its ability to have multireference character upon positively charged radical species. Density functional theory (DFT) calculations using Gaussian software were performed upon alkene/alkyne addition. Orbital symmetry regulates the reaction and ligand centered cis-interligand dithioether formation products were favored. Calculations showed positive radical species to have low-spin ground state confirming that dicationic Re-dithioethers have multireference character coupling between Re dyz and styrene py orbitals. Metal stabilized radicals are crucial to ligand-metal interactions upon alkene/alkyne addition. Neutral radicals do not experience multireference character upon DFT calculations and are less favored upon addition. Ruthenium tris(thiolate) complexes experienced faster styrene addition due to the lower charge on ligand. This mechanism was studied at Wenzhou University, China and published a month ago. Other transition metal-stabilized thiyl radicals are hoping to be looked at in the near future. https://sjfc.zoom.us/rec/share/NnqhaSvoj0Iza5sCmiDpIePJRu2GSyxASQnlKKP9FCx8LnDS1n1Oa_9zx9zCvMG6.B2q-875mAA-FhulrMgmC!nS7
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Thursday, March 16, 2023Friday, March 24, 2023Justin GabrielSenior chemistry major, St. John Fisher UniversityAn Exploratory Study of a Simple Approach for Evaluating Drug Solubility in Milk Related
Vehicles		Milk related materials are frequently used as a vehicle for drug product administration.Therefore, drug solubility information in milk related vehicles is desirable for prediction of how they may influence in vivo drug release and bioavailability. However, there are very limited data published on this topic. Dexamethasone, nifedipine, piroxicam, and prednisolone were selected as model drugs to represent a wide range of physicochemical properties. Their solubilities were determined at cold, room, and warm temperatures in pH 6.8 phosphate buffer and whole milk. The overall results confirmed that milk greatly improves the solubility of poorly water-soluble drugs. However, the extent of improvement and mechanism of solubilization appeared unique for each drug, highlighting the importance of evaluating milk solubility experimentally.https://sjfc.zoom.us/rec/share/6xG9KPNKUnUKnsXUKolVg57rm77X26eWcgSdsEAz1_46lCGdIDUmhEgOjKSZefv9.jseF2TtAaLBICKUg PLF?&C47
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Thursday, March 23, 2023Friday, March 31, 2023Josiah BowersSenior chemistry major, St. John Fisher UniversitySubstrate Selectivity and Inhibition of MINA53 and NO66
Although their typical physiological purpose is not well understood, the over-expression of MINA53 and NO66 in some cancers makes them a possible target for treatment. Researchers tried to find a way to target these enzymes by synthesizing a peptide that resembled their usual target, but replacing the amino acid substrate (histidine) (with homologous structures in hopes that it would inhibit the enzyme. First these peptides were tested to see whether the hydroxylation reaction of the enzymes were still carried out, and, with none of the sequences reacting efficiently, their effectiveness as inhibitors was tested. Three of the histidine homologs were found to effectively inhibit MINA53 but none were very effective for inhibiting NO66. Hopefully, this study, paired with a better understanding of the importance of these enzymes, will lead to effective ways to treat cancers where these enzymes are over-expressed.https://sjfc.zoom.us/rec/share/6gU9S6uPY6BXmNRrarFltS7Ccy8dwq5zjyD33iClM4_pT8jBauTjdYIeSf9oqjFI.bIN4i2GvAMoUnw7lVcWA=0yF
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Friday, April 7, 2023Good Friday, no seminar
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Thursday, March 30, 2023Friday, April 14, 2023Emma GarnSenior chemistry major, St. John Fisher UniversitySynthesis and Characterization of an Aspartame-Based Chiral Ionic Liquid for Potential Applications in EnantioseparationsPure enantiomers are constantly in high demand in the drug and food industries. The difference between a medication containing an R or S isomer could alter the effectiveness of the drug and even cause adverse side effects. Although the FDA does not require that pharmaceuticals be made up of single enantiomers, but this has become a popular area of research in the pharmaceutical industry in order to create the most effective drugs, leading to the increasing interest in chiral separation techniques. Recently, investigations of chiral ionic liquids (CILs) as stationary phases or chiral selectors for chromatographic techniques such as gas chromatography (GC), high performance liquid chromatography (HPLC) and extractions have grown. An aspartame-based CIL was prepared, and the thermal stability was evaluated using thermal gravimetric analysis. The CIL was found to possess a high decomposition temperature of 366 °C. The purity of the CIL and other physical and chemical properties such as melting point and chiral recognition ability of the CILs are being investigated.
https://sjfc.zoom.us/rec/share/5ZU_U6-PeWg1Kx8B0GgAYbSu1fvDuAuEgAWzWHZ8bEHz7uSJILEVI9eAb0uObrU.1a6u-Y1PI8U8VAw1 v+.mQ1ig
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Tuesday, April 11, 2023Friday, April 21, 2023Skylor Ou YangSenior chemistry major, St. John Fisher UniversityAcetaldehyde Enhances Alcohol Sensitivity and Protects against Alcoholism: Evidence from Alcohol Metabolism in Subjects with Variant ALDH2*2 Gene AlleleAlcoholism is a complex behavior trait influenced by multiple genes as well as by sociocultural factors. Alcohol metabolism is one of the biological determinants that can significantly influence drinking behaviors. Alcohol sensitivity is thought to be a behavioral trait marker for susceptibility to develop alcoholism. The subjective perceptions would be an indicator for the alcohol preference. To investigate alcohol sensitivity for the variants ADH1B*2 and ALDH2*2, sixty healthy young males with different combinatory ADH1B and ALDH2 genotypes, ADH1B*2/*2–ALDH2*1/*1 (n = 23), ADH1B*2/*2–ALDH2*1/*2 (n = 27), and ADH1B*1/*1–ALDH2*1/*1 (n = 10), participated in the study. The subjective perceptions were assessed by a structured scale, and blood ethanol and acetaldehyde were determined by GC and HPLC after an alcohol challenge in two dose sessions (0.3 g/kg or 0.5 g/kg ethanol).https://sjfc.zoom.us/rec/share/4iDFI78iH35Gwr3hfLAAe6nRTi2WS6EDWf5jqyFLouEPisFoWsitemU0DrBKWCKt.-D9LddW1v_164ijF 85F5=uSB
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