Research Archives | Page 7 of 8 | Chemistry Newsblog

Published July 20, 2015

Xu Xiang
PhD Defense
Doctoral Candidate, Department of Chemistry
Advisor: Dr. Patrica Heiden

Friday July 24, 2015
Memorial Union Ballroom A-1
9:00 a.m.

Novel Drug Delivery Systems: Thermo-responsive drug delivery designs and Multi-drug delivery scaffold designs

Abstract:
This research has three parts: two deal with novel medical devices for drug delivery, and one looks at properties of fish scales as an abundant waste resource that can be modified to have value in medical and other areas. This presentation discusses two novel drug delivery designs, including their synthesis and characterization. These nanoparticle devices address two current challenges in drug delivery. The first is designing a drug-carrier to more efficiently deliver toxic (e.g. chemotherapy) drugs, which harm all cells. So non-specific delivery of the drug is wasteful and harmful to the patient. Knowledge gained from a fundamental study of the effects of polymer architecture (linear amphiphilic diblock and triblock copolymers and star copolymers) and end group polarity, on thermally triggered drug delivery led to selecting two diblock copolymers to assemble into novel gold-core hybrid nanoparticles. These nanoparticles were tested for their ability to reduce low temperature release and efficiently release the drug at a triggered temperature. The second drug delivery system extended the capabilities of a new type of tissue support device (a scaffold) by showing that the system can independently control the simultaneous release of different drugs, and that the spatial distribution of these drugs within the device, called a “nanoparticle fiber”, can be controlled. Three different model drugs were assembled and their release proven, within the nanoparticle fiber. This work succeeded in yielding a novel, flexible, and robust system of assembled fibers of nanoparticles that could independently control the release of multiple drugs.

Total Synthesis of Belizentrin

Published July 1, 2015

By

Total Synthesis of Belizentrin

Shahien Shahsavari
Original Research Proposal
Michigan Technological University
Department of Chemistry
Advisor- Dr. Shiyue Fang
Monday July 6, 2015
10:00 am
Chem-Sci 101

Abstract

Marine organisms are known to produce some of the most bioactive secondary metabolites found in nature. Currently, many of these marine-derived molecules are used as “first-in-class” drugs in the market. This proposal describes the total synthesis of belizentrin, a novel polyketide-derived macrocycle isolated from the marine dinoflagellate Prorocentrum belizeanum. Belizentrin has already demonstrated effective changes in neuronal survival assays in vitro at nanomolar concentrations. Additionally, its highly bioactive properties and structural similarities with other known immunosuppressant compounds make it a valuable target for medical research. However, since the extraction yield is minimal, it is essential to produce this compound in larger quantities from readily available starting materials for a complete investigation of its biological activities. The overall synthetic strategy involves a convergent late-stage coupling of three major fragments. The key features of the synthesis include iterative asymmetric allylic substitutions, titanium-catalyzed asymmetric epoxidation of terminal olefins, and the Yamaguchi macrolactonization to form the macrocyclic core of the molecule.

Valenzano on Research Funding Tour

Published June 8, 2015

By College of Engineering

News

Group Faculty Visit to Washington, DC

For the past five years, Michigan Tech deans and the vice president for research have sponsored a group visit to Washington, D.C. for early-career research faculty. To date, 70 Michigan Tech faculty and administrators have participated.

Trip participant, Loredana Valenzano shared these comments about the trip:

“What I enjoyed most was having the feeling that, indeed, PDs [program directors] and POs [program officers] are there to help, and to provide valuable guidance especially to those of us who are trying to build a career in the STEM in times where funding is decreasing and the competition is high. The availability to talk and somehow the capability to alleviate frustrations and anxieties which the people we had the chance to interact with provided, was a pleasant and encouraging revelation. I believe that having the occasion to see with our own eyes how the big machine on the East Coast works is absolutely a key aspect to shoot for success.”

T Synthesis of Isobractatin and Neobractatin

Published April 20, 2015

By

Shanshan Hou
Original Research Proposal
Michigan Technological University
Department of Chemistry
Advisor- Dr. Lanrong Bi
Tuesday April 21, 2015
9:00 am
Chem-Sci 106

T Synthesis of Isobractatin and Neobractatin

Abstract
The new Garcinia derivatives, neobractatin and isobractatin, will be synthesized. These compounds are caged-prenylxanthones which are isolated from Chinese native Garcinia bracteata. They displayed strong inhibition of cancer cells, which could significantly induce cell apoptosis and inhibit autophagy. However, the compounds which are extracted from the Chinese native Garcinia species have very low yield. Total synthesis of these derivatives will provide adequate quantities for biological studies. In addition, the new synthetic methodologies could not only produce the target compounds but also give rise to their isomers which could be potential anti-tumor candidates and used for future research.

Interfaced Heterogeneous Nanodimers

Published April 9, 2015

By

Chemistry Seminar
Dr. Yugang Sun
Center for Nanoscale Materials, Argonne National Laboratory
Friday, April 17, 2015 3:00pm Chem-Sci 101

Interfaced Heterogeneous Nanodimers
Abstract:
Synthesis of interfaced nanoparticle dimers made of asymmetric compositions (i.e., interfaced heterodimers) is challenging because it is difficult to manipulate the nanoparticles’ surface properties to control the assembly and/or growth of different nanoparticles. In this presentation, the general principle will be first introduced for the formation of interfaced heterogeneous dimers made of different inorganic nanodomains that exhibit either crystalline or amorphous structures. Although many different combinations are possible, the heterodimers containing plasmonic components (e.g., gold and silver nanodomains) will be focused in this presentation to highlight a number of synthetic methods and unique properties observed in heterodimers. For example, a seed-mediated, surface-confined epitaxial overgrowth strategy is capable of synthesizing high-quality interfaced Au-Ag heterodimers with varying sizes. Au and Ag share a common face-centered cubic lattice and have nearly identical lattice constants, which facilitates epitaxial overgrowth and allows direct contact between the Au and Ag domains. The interfaced Ag nanodomains can be chemical transformed to hollow nanoshells of other materials through a galvanic replacement reaction, resulting in the formation of interfaced dimers made of solid Au nanoparticles and hollow nanoshells. Due to the direct contact between the two components in each interfaced dimer, strong coupling between them are expected to induce new properties that cannot be observed from any individual components.

Biography:

Dr. Yugang Sun is a Scientist at the Center for Nanoscale Materials, Argonne National laboratory. He received his B.S. and PhD degrees from University of Science and Technology of China in 1996 and 2011, respectively. He worked as a Postdoc at University of Washington at Seattle (with Prof. Younan Xia) from 2001 to 2003. During 2004-2004, he had been working with Prof. John Rogers at University of Illinois at Urbana-Champaign as a postdoctoral fellow. In August 2008, he was appointed as an Assistant Scientist at Argonne National laboratory. He was promoted to Scientist in January 2010.

Dr. Sun’s research interests focus on developing novel approaches for the synthesis of a wide range of nanostructures including metal nanoparticles with well-controlled morphologies, single-crystal semiconductor nanostructures with mechanical flexibility, and metal/semiconductor nanocomposites with multiple functionalities. As of now, he has published more than 130 research papers, with an h-index = 47 and citation times > 23,400. He was honored as one of the “Top 100 Materials Scientists with highest impact score (2000-2010), Rank #5” by Thomson Reuters.

Zintl and Polar Intermetallic Compounds

Published March 31, 2015

By

Chemistry Department Seminar Faculty Candidate
Dr. Fei Wang
Polymer and Material Chemistry, Lund University Sweden
Monday April 6, 2015
4:00 PM, MUB~ Alumni Lounge A

Abstract:
Zintl and polar intermetallic compounds are compounds between electropositive metals (e.g. alkali, alkaline earth, and rare earth) and electronegative metals/metalloids (e.g. late transition and post transition elements). Just like their constituent elements, these compounds are also metals/metalloids. Meanwhile, partial charge transfer is expected from the electropositive metals to the electronegative metals/metalloids, the latter of which are formal “anions” and covalent interactions can occur among them. Therefore, Zintl and polar intermetallic compounds possess simultaneously metallic, ionic, and covalent characteristics. I will demonstrate what will happen when metallicity, covalency, and ionicity coincide and interplay with each other.
Besides, the bonding between the “anionic” electronegative metals/metalloids is also intriguing. The well-know electron counting rules, such as the octet rule and the Wade-Mingo’s rules, fail frequently in rationalizing the bonding in Zintl and polar intermetallic compounds. I will present a few examples to illustrate the cause, with emphasis on the involvement of d-orbitals and the relativistic effects in bonding.

Biography:
I obtained my master’s degree from Zhejiang University in China in 2005. There I worked on morphology controlled syntheses of inorganic compounds under the direction of Prof. Linhai Yue. After that, I joined Prof. Gordon J. Miller’s research group in Iowa State University, where I developed the majority of my expertise in solid state chemistry, including high temperature synthesis, X-ray crystallography, and first-principle computations. In 2011, I received my PhD degree in inorganic chemistry and moved to Stuttgart, Germany, working as a postdoc in Prof. Martin Jansen’s department in Max Planck Institute for Solid State Research. My project is on the syntheses, structures, and rationalization of thallium cluster compounds featuring significant relativistic spin-orbit coupling. Currently, I am in Prof. Sven Lidin’s group at Lund University in Sweden, working on my second postdoc position which started in 2013 and is supported by the Wenner-Gren Scholarship. Here, my expertise has been further broadened with incommensurate crystallography and thermoelectric materials.

Sustainable Clean Energy Based on Solid State Ionic Materials and Devices

Published March 11, 2015

By

Chemistry Department Seminar Faculty Candidate
Dr. Jianhua Tong
Colorado Center for Advanced Ceramics,
Metallurgical & Materials Engineering, Colorado School of Mines
Thursday March 19, 2015
MUB ~ Alumni Lounge A
1:00 pm

Abstract
It is estimated that global energy consumption will be doubled by 2035 due to growth in global population and continued industrialization of developing countries. Solar energy is a renewable clean energy source and can satisfy the rising energy demand eventually from long-term point of view. However, fossil energy, a non-renewable carbon-based energy source, still dominates the energy supplies in near future. Therefore, the efficient conversions of fossil energy and the efficient storage of solar energy are also very important from both scientific and industrial point of view. Among the energy materials, the leading actors for energy conversion and storage, solid state ionic materials have found a great number of applications such as catalytic membrane reactors, fuel cells, electrolysis cells, heterogeneous catalysts, photovoltaics, thermal electronic devices, materials for solar thermal chemical fuels production, and catalysts for oxygen reduction reaction and oxygen evolution reaction etc.
In the first part of the talk, I would like to briefly highlight my significant research contributions to sustainable clean energy based on solid state ionic materials and devices. In the second part of the talk, I would like to intensively focus on my recent discovery of perovskite-type oxides as promising materials for solar thermochemical (STC) fuels production through two-step redox cycles.

Bio:
Dr. Jianhua Tong is working as an Associate Research Professor in Colorado Center for Advanced Ceramics at the Colorado School of Mines (US). He received his PhD degree in Dalian Institute of Chemical Physics, Chinese Academy of Sciences. Subsequently, he worked as NEDO project researcher in Research Institute of Innovative Technology for the Earth (Japan), JSPS fellow in National Institute of Advanced Industrial Science and Technology (Japan), and postdoctoral scholar in California Institute of Technology (US) for several years. He has made some important contributions to the materials and devices for sustainable clean energy by focusing on fuel cells, catalytic membrane reactors, pure hydrogen production, pure oxygen production, natural gas conversion, mixed conducting oxides, proton conducting ceramics, and solar thermochemical fuels etc. He published >60 peer-reviewed papers, filed >15 patents, and got citations >2500 and H-index >24.

Synthesis of Lipodiscamide A

Published March 4, 2015

By

Ashok Khanal
Original Research Proposal
Michigan Technological University
Department of Chemistry
Advisor: Dr. Shiyue Fang
Thursday, March 5, 2015
10:00 am Chem Sci ~ Room 211

Synthesis of Lipodiscamide A

Abstract:
Lipodiscamide A is a cytotoxic lipopeptide extracted from the marine sponge Discodermia kiiensis. Research on lipodiscamide A has been fueled by its properties such as cytotoxicity, and antimicrobial and immunosuppressive activities. In this proposal, the total synthesis of lipodiscamide A will be described. Structurally, lipodiscamide A contains an unsaturated fatty acid moiety and a hexapeptide moiety. The two moieties are linked together with two ester bonds to form a macrocycle. The yield of this compound from natural sources is very low. Therefore, its synthesis from readily available starting materials resulting in large amounts of lipodiscamide A is important for full investigation of its biological activities.

Impact of Molecules, Morphology and Nano/microstructures in Sensing, Optical, Energy and Display applications

Published February 23, 2015

By

Chemistry Department Seminar Faculty Candidate
Dr. Kaushik Balakrishnan
Monday March 2, 2015 – 4:00 PM
Chem-Sci 101

Abstract
The ability to control optical and electrical properties of materials as a function of size and dimension has profound implications in numerous miniaturized technologies such as sensing, communication, lighting, display, optical and electrical circuits, and energy applications. This talk will unravel critical information about molecular stacks from individual molecular entities and advance to our newly uncovered possibilities to co-¬‐localize, and co-¬‐assemble two distinct molecular entities in a single stack of highly organized assemblies. Such self-¬‐assembled structures show immense potential in photonic and opto-¬‐electronic devices and are a promising approach for advancing organic electronic materials in advance applications.
Second part of this talk will focus on energy harvesting and storage. The nanocarbon structures such as carbon nanotubes, and graphene are highly attractive for use as electrodes in supercapacitors, and lithium ion batteries. The detailed workings of the recent breakthroughs in ‘in-¬‐plane’ geometry that enables an ultrathin, flexible, and solid-¬‐state graphene based supercapacitors will be described. Also, nanocomposites for achieving high performance electrolytes capable of withstanding high temperatures with large voltage windows for next generation of supercapacitors and batteries will also be described.

Synthesis of Taiwaniadducts I and J

Published February 23, 2015

By

Xin Yan
Original Research Proposal
Michigan Technological University
Department of Chemistry
Advisor-Dr. Lanrong Bi
Thursday, February 26, 2015
9:00 am Admin Building Room 404
Abstract
The Taiwaniadducts I and J, as cycloadducts of terpene quinones from taiwania cryptomerioides, will be synthesized. These two compounds are isolated from Taiwania cryptomerioides hayata, a large coniferous evergreen species common to Taiwan. They have potential in medical applications due to the breadth of their biological activities. However, low yields of these naturally extracted compounds limits further research on their biological activities and no synthetic approaches to these two compounds have been reported before. Herein, we design a synthetic route which can provide adequate quantities of target compounds for further biological studies. Moreover, the design methodology involved in this proposal may show a reasonable approach to the synthesis of this kind of cycloadducts.

Category: Research