Evolution of Selected Isoprene Oxidation Products in Dark Aqueous Ammonium Sulfate

MS Defense:  DM Ashraf Ul Habib
Chemistry Department

Lynn Mazzoleni, Advisor
Thursday, December 4  1pm,  Chem Sci 101
Evolution of Selected Isoprene Oxidation Products in Dark Aqueous Ammonium Sulfate

The climate of the world is changing but our understanding of atmospheric processes is limited. Atmospheric aerosol is a trace but very influential medium of the atmosphere. Especially little is known about the organic aerosol components and their aqueous phase chemical evolution. To address this, the aqueous phase processing of glyoxylic acid, py­ruvic acid, oxalic acid and methylglyoxal was studied simulating dark and radical free atmospheric aqueous aerosol. A novel observation of the cleavage of a carbon-carbon bond in pyruvic acid and glyoxylic acid leading to their decarboxylation was made in the presence of ammonium salts but decarboxylation was not observed from oxalic acid. The empirical rate constants for decarboxylation were determined and are competitive with nighttime OH radical reactions. The structure of the acid, ionic environment of the solu­tions and concentration of species were all found to affect the rate of decarboxylation. A tentative set of reaction mechanisms is proposed involving nucleophilic attack by ammo­nia on the carbonyl carbon leading to fragmentation of the carbon-carbon bond between the carbonyl and carboxyl carbons. Under similar conditions in atmospheric aerosol, the aqueous phase processing may markedly impact the physicochemical properties of aerosol.

 

Synthetic Oligodeoxynucleotide Purification via Catching by Polymerization

Suntara (Boat) Fueangfung

Advisor: Dr. Shiyue Fang

Doctoral candidate, Department of Chemistry

Michigan Technological University

Friday, December 5, 2014, 9:00 am

Admin Building, Room 404

PhD Defense

 

Synthetic Oligodeoxynucleotide Purification via Catching by Polymerization

Abstract

Large quantities of pure synthetic oligodeoxynucleotides (ODNs) are important for preclinical research, drug development, and biological studies. These ODNs are synthesized on an automated synthesizer. It is inevitable that the crude ODN product contains failure sequences which are not easily removed because they have the same properties as the full length ODNs. Current ODN purification methods such as polyacrylamide gel electrophoresis (PAGE), reversed-phase high performance liquid chromatography (RP HPLC), anion exchange HPLC, and affinity purification can remove those impurities. However, they are not suitable for large scale purification due to the expensive aspects associated with instrumentation, solvent demand, and high labor costs.

To solve these problems, two non-chromatographic ODN purification methods have been developed. In the first method, the full-length ODN was tagged with the phosphoramidite containing a methacrylamide group and a cleavable linker while the failure sequences were not. The full-length ODN was incorporated into a polymer through radical acrylamide polymerization whereas failure sequences and other impurities were removed by washing. Pure full-length ODN was obtained by cleaving it from the polymer. In the second method, the failure sequences were capped by a methacrylated phosphoramidite in each synthetic cycle. During purification, the failure sequences were separated from the full-length ODN by radical acrylamide polymerization. The full-length ODN was obtained via water extraction. For both methods, excellent purification yields were achieved and the purity of ODNs was very satisfactory. Thus, this new technology is expected to be beneficial for large scale ODN purification.

Proposals in Progress

PI Xiaohu Xia (Chem), “Facile Removal of Surface Ligands from Supported Platinum-Group Metallic Nanocrystals,” American Chemical Society

PI Loredana Valenzano (Chem), “Bringing New Efficiencies in Petroleum Refining Processes: A Quantum Chemical Investigation of Novel Porous Materials and Metal Oxide Surfaces for Olefin and Paraffin Separation,” American Chemical Society

PI Lanrong Bi (Chem/BRC), “Buckyballs-Based Mitochondrial Drug Delivery System for the Prevention and Treatment of Ischemia/Reperfusion Injury,” US Department of Health and Human Services, NIH

PI Marina Tanasova (Chem), “Discovering Probes to Overcome Cancer Resistence to DNA Alkylating Chemotherapy by High Throughput Evaluation of Polymerase Inhibition,” US Department of Health and Human Services, NIH

PI Lanrong Bi (Chem/BRC) and Co-PI Qinghui Chen (KIP/BRC), “Target Mitochondrial Fusion Process: Engineering of a Nanoparticals-Based Mitochondrial Drug Delivery Platform,” US Department of Health and Human Services-NIH

PI Martin Thompson (Chem), “Development of a Biological Platform to Study Histone Modifications,” NSF

PI Lynn Mazzoleni and Co-PI Marina Tanasova (Chem), “Collaborative Research: The Role of Inorganic Salts in Functionalization and Fragmentation of Isoprene Oxidation Product—A Molecular-Level Investigation,” NSF

PI Tarun Dam (Chem), “Role of Glycoconjugate Scaffolds in Lectin Recognition,” NSF

PI Haiying Liu and Co-PI Ashutosh Tiwari (Chem), ” BODIPY-Based Ratiometric Near-Infared Fluorescent Probes for Zinc(II) and Active Oxygen Species,” NSF

Proposals in Progress

Haiying Liu (Chem), “Point-of-Care Rapid Detection by Label Free Cell and Nucleic Acid Assays,” Oakland Univeristy

Lynn Mazzoleni (Chem), “Collaborative Research: Nitrogen Partitioning and Evolution of Particulate Organic Nitrogen in Peat Fire Emissions,” National Science Foundation

Rudy Luck (Chem), “SusChEM: Using Abundant First Row Transition Metals to Accomplish Cross-Coupling for the Synthesis of Specific Drugs,” National Science Foundation

BRC Travel Awards for Fall 2014

The Biotechnology Research Center has announced its fall 2014 Travel Awards. The award recipients follow:
Post-doctoral Research Scientist Presentation
Sachin Teotia (Bio Sci), Plant and Animal Genome XXIII Conference (poster)
Lijun Zhang (Bio Med), TERMIS–AM 2014 (podium)

Graduate Student Presentations
Suntara Fueangfung (Chem), 248th ACS National Meeting and Exposition (poster)
Maria Gencoglu (ChE), 2014 AIChe Annual Meeting (podium)
Maryam Khaksari (ChE), SciX 2014 (podium)
Hao Meng (Bio Med), BMES 2014 Annual Meeting (poster)
Sandra Owusu (SFRES), IUFRO World Congress (poster)
Durga Pokharel (Chem), 248th ACS National Meeting and Exposition (poster)
Yu Wang (Bio Med), IEEE International Ultrasound Symposium (poster)
Jingtuo Zhang (Chem), 248th ACS National Meeting and Exposition (poster)<
Undergraduate Student Presentation
Mitchell Tahtinen (Bio Med), 2014 BMES Annual Meeting (poster)

In Print

Postdoctoral associate Shilei Zhu, graduate student Jingtuo Zhang, postdoctoral associate Jagadeesh Janjanam, graduate student Giri Vegesna, assistant professor Ashutosh Tiwari, professor Haiying Liu (Chem), et al. published a paper titled “Highly Water-Soluble BODIPY-Based Fluorescent Probes for Sensitive Fluorescent Sensing of Zinc (II)” in Journal of Materials Chemistry B. This paper has been named one of the Most Accessed Manuscripts for Journal of Materials Chemistry B for 2013.

Graduate students Giri K. Vegesna, Jianheng Bi, Jingtuo Zhang, postdoctoral associate Jagadeesh Janjanam, undergraduate student Connor Olds, Assistant Professor Ashutosh Tiwari, Professor Haiying Liu (Chem), et al published a paper titled “.pH-Activatable Near-Infrared Fluorescent Probes for Detection of Lysosomal pH Inside Living Cells” in Journal of Materials Chemistry B.

Professor Haiying Liu (Chem), et al. published a paper titled “Interfacial Charge Transfer Events of BODIPY Molecules: Single Molecule Spectroelectrochemistry and Substrate Effects” in Physical Chemistry Chemical Physics.

Chemistry Doctoral Student Suntara Fueangfung

Chemistry doctoral student Suntara Fueangfung (advisor: Associate Professor Shiyue Fang) was recognized at the Sigma Xi 2014 International Research Conference earlier this month. Fueangfung’s research poster presentation, “Purification of Synthetic Oligodeoxynucleotides via Catching by Polymerization,” was rated superior in the Chemistry Graduate Division.

The award for superior-rated presentations includes being nominated for membership by the Sigma Xi Board of Directors, payment of the initiation fee and the first year’s dues and a medal. Fueangfung will graduate from Michigan Tech this December.

For more information visit the Sigma Xi website.

Xiaohu Xia joins the Department of Chemistry as an Assistant Professor

Xiaohu Xia, PhD
Xiaohu Xia joins the Department of Chemistry as an assistant professor. He comes to Michigan Tech from the Georgia Institute of Technology.

Xia has a PhD in Biochemistry and Molecular Biology and a bachelor’s in biotechnology from Xiamen University in China.

Xia’s research interests are development of novel nanomaterials with well-controlled shapes and enhanced properties, and biomedical and catalytic applications of advanced nanomaterials. He has been published in the Journal of the American Chemical Society, Advanced Materials, and Frontiers of Physics.

Lake Superior’s History and Future

 

On Tuesday, Nov. 18, Professor Sarah Green, expert on Lake Superior, will lead a discussion titled “Lake Superior’s History and Future,” at the Carnegie Museum. Refreshments will be served at 6:30 p.m., with the discussion following at 7 p.m.

The event is part of a monthly series of sessions on the Geoheritage and Natural History of the Keweenaw, at the Carnegie Museum in Houghton. The discussions are aimed at the general public, but discuss current research and science.