ChemSemBlog

The presenter for this week was Joseph Heinzelmann. He completed his Bachelor’s of Science in Chemistry and began working at Dendritic Nanotechnologies (DNT). Heinzelmann is currently a DNT products manager, whose main focus of research is PAMAM dendrimers. A dendrimer is a highly organized polymer built from repeating branching made in order of molecular complexity. PAMAM dendrimers represent an exciting new class of macromolecular architecture called “dense star” polymers. Dendrimers have a high degree of molecular uniformity, narrow molecular weight distribution, specific size and shape characteristics, and a highly- functionalized terminal surface. The manufacturing process is a series of repetitive steps starting with a central initiator core. Each subsequent growth step represents a new “generation” of polymer with a larger molecular diameter, twice the number of reactive surface sites, and approximately double the molecular weight of the preceding generation.

Nomenclature or dendrimers begins with branching then the surface groups. Dendrimers were found to be 1-10nm in diameter, built using organic chemistry, and consisted of branching which aided in the growth of functional groups on the outside. They were also found to be cross linkers interacting with other polymers, gaining strength and losing flexibility, allowing protein and antibodies to line up, making it easy to detect where a heart attack was taking place. Dendrimers also help create osmotic pressure of a molecule without losing it through a membrane. An interesting part of their structure is a void space which allows for carrying molecules such as drugs. This capacity can make them useful in targeting cancer cells. Heinzelmann has an idea that the ligands could be targeting groups, and the drugs used in cancer treatments could be inserted in these void spaces, then the dendrimer could be directed to the area of cancer cells, centering the drugs on them, killing them. Another idea is that the dendrimers can be modified to carry a genetic code involving siRNA-small interfering RNA.

With all of these plans for dendrimers there is the problem of manufacturing. They must be taken through a regulatory process, get FDA approved, solve safety issues, and the drug delivery takes time. Purity has also been an issue, the dendrimers cannot touch each other or they will create dimmers. One must also use large excess of reactant about 100 equivalents per surface. Heinzelmann then concluded that PAMAM dendrimers have great promise, endless possibilities, trouble securing funding, and the manufacturing process must be improved and that there are still new classes of polymers still being developed. He also gave very useful information about the future careers awaiting chemistry majors and believes that one must stay open minded and keep learning.

During this presentation Heinzelmann’s audio was well, made eye contact with the audience, went through the slides quickly and finished on time. I found this topic to be very interesting and many students seemed to be engaged. There were many questions answered at the end and all of these questions were answered well. This presentation did encourage me to learn more about PAMAM dendrimers and I wouldn’t mind doing summer research on this topic. I wasn’t really encouraged to go to the speaker’s school for graduate studies, but Heinzlemann didn’t really speak about it, but he was available to answer question if one was to ask at the end of the presentation.

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This week’s speaker was Mary L. Kraft, who received a Ph.D. from the Department of Chemistry at the University of Illinois at the Urbana- Campaign. She presented on her current research which focuses on the development of high resolution compositional imaging techniques used to investigate the causes and consequences of lipid and cholesterol distribution within the plasma membrane. Specifically the distribution of nitrogen-15(N-15) and carbon-13(C-13). During this presentation Kraft made much eye contact, had an adequate voice level, and enjoyed the topic. I found this topic of applied research very interesting since it also tied in with subjects I’m studying now. Some new things I learned dealt with the incorporation of N-15 and C-13 in sphingolipids and other cellular lipids. It was amazing that this Study took seven days in which the different cells were fed N-15 and after two days any trace of N-14 had disappeared.

Lipid domains are enriched by cholesterol (CHO) and sphingolipids in the plasma membrane are hypothesized to influence membrane-mediated processes. During their research they developed a raft hypothesis which talks about the plasma membrane of cells that are made up of a combination of glycosphingolipids and protein receptors organized in glycolipoprotein microdomains termed lipid rafts. These specialized membrane microdomains compartmentalize cellular processes by serving as organizing centers for the assembly of signaling molecules, influencing membrane fluidity and membrane protein trafficking, and regulating neurotransmission and receptor trafficking. Raft membranes are enriched for cholesterol and sphingolipids and contain clustering proteins trans membrane proteins. They found virus envelopes to contain more CHO and sphingolipids than the host cell. There were also virus buds from domains enriched by CHO and sphingolipids.

This research group also wanted to determine whether the depletion of CHO or sphingolipids had adverse affects to the budding and signal transduction adhesion and other cellular processes. There were different rates of diffusion due to different environments, but they were still unsure whether CHO depletion really affected anything. Direct approaches to probe cell membrane organizations were used involving Secondary Ion Mass Spectrometry (SIMS). Some problems that arose were poor lateral resolutions and the image was 12X larger than needed. They then tried using a high- resolution SIMS which gave a good map of the elemental and isotopic composition of the N-15 and C-13 in the sphingolipids and other cellular lipids. This machine was more specific and it’s fascinating that there are only seven in the country.

In another part of Kraft’s study a distinct stable isotope of the elements mentioned were incorporated into each membrane component. Component-specific secondary ions revealed the distribution in each lipid. N-15 was then found to incorporate into 100% of cellular sphingomyelin, while C-13 with its various lengths were incorporated into all cellular lipids or fatty acids. Using Nano-SIMS gave Kraft the ability to see enriched N-15 and C-13 region and whether or not the cell became damaged. This helped them in gathering accurate results and allowed them to see what was truly happening. In conclusion, they were able to find that the sphingolipids were heterogeneously distributed, which supported their raft hypothesis. They have future plans to work with influenza and virus budding.

Many students seemed to enjoy the presentation and many questions were asked during the end. These questions were answered well clarified many points in the presentation. The presentation did encourage me to learn more about the subject and it seemed like a very intriguing process. The presenter didn’t speak much about her school of graduate studies so I wasn’t necessarily encouraged to go there, but I’m sure she would have been open to questions. This presentation gave a direct visualization of heterogeneous sphingolipid distribution.

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This week’s speaker was Mu-Hyun (Mookie) Baik. He has a Ph.D in theoretical in inorganic chemistry from the University of North Carolina at Chapel Hill and has started an independent academic career. With his research group the topics of interest are transition metal chemistry with a heavy emphasis on catalysis. Currently Baik is working with computer stimulations in studying water oxidation, which they found was a good source for electrons. During this presentation Baik had good audio, explained the slides well, was enthusiastic about the topic, and made a lot of eye contact connecting with the audience. I found this topic to be very interesting and it introduced me to many aspects involving water oxidation and computer stimulators.

It was first mentioned that computer stimulators can offer great insights, but number crunching can cause problems. It helps with post-dictions, but predictions are difficult. They must make sure that the data is real, relevant, and useful. Water oxidation yields two O_2 molecules, 4 protons, and 4 electrons. Baik and his group want to do artificial photosynthesis using lots of water. They discovered that by splitting water they can get electrons. They took water, removed electrons, and generated two oxygen molecules. They then used a ruthenium (Ru) based water oxidation catalyst. Each Ru(III) center has at least one unpaired electron and they wanted to find a triple ground state. Electron paramagnetic resonance and magnetic susceptibility experiments suggests a diamagnetic ground state. All electrons appear to be paired and it was discovered that that there were three possible states to RU: ferromagnetic, anti-ferromagnetic, and diamagnetic. The anti-ferromagnetic state was favored due to its higher energy. There is a proton coupled redox process, removing either a proton or a electron. The transition metals are very reactive and can be seen using computer calculations. They found the rate determining transition rate.

Baik and his group currently want to make a Fe-based water oxidation catalyst. Iron was picked next due to its low costs and large quantity. They also want to connect the water oxidation catalyst with CO_2 reduction catalyst and were successful. They tend to make molecules with computer first then they do the chemistry.

This presentation did encourage me to learn more about the subject and I would perform summer research on this subject. The presentation did encourage me to attend Indiana University, Baik’s school of studies. We were shown pictures of a beautiful campus, with appealing buildings and labs. Water oxidation catalysis was interesting and it’s amazing how much energy can be given off by the splitting of water.

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This week’s speaker was Amanda B. Hummon, who is currently teaching special topics in Biochemistry and Notre Dame. Some of her publications have appeared in premier journals, such as Cancer Research and she is currently researching analytical chemistry and cell and molecular biology. Dr. Hummon presented on colon and rectal cancer which we learned was very different and shouldn’t be put together. Her presentation was organized, had good audio with clear voice, went quickly, and was well explained. I found this topic to be very interesting I learned of the process that it takes when determining a tumor in the colon and rectal area.

Some new things that I learned were the characteristics of cancer cells, oncogenesis, and the difference between colon and rectal cancer. Cancer cells have proliferation, insensitivity to growth signals in the body, angiogenesis (formation of new blood vessels that grow into the tumor, giving it nutrients and oxygen to assist its growth), and WNT signaling (describes a network of proteins well known for their roles in embryogenesis and cancer). When looking at cancer cells they focus on the disease of the genome, DNA, RNA, protein, the network, function, and pathway.

Some of the projects that Dr. Hummon performed involved examining transcriptional deregulation in primary colon and rectal adenocarcinomas. They found that in colon aneuploid adenocarcinoma there were 58 chromosomes, while the normal diploid is 48 chromosomes. In the cancer cell some chromosomes had more than two copies and they gathered this information using comparative genomic hybridization process.

Other activities that they performed involved taking colon and rectal samples from patients in whom they compared the tumor versus the mucosa and their gene expressions. They found 17 genes having a fivefold difference between tumors and mucosa. The immune genes were expressed differently and the difference could be clearly seen. They also found the genes that turned on, trying to fight the cancer.

When looking at the difference between colon and rectal cancer, out of 5,000 genes only 400 changed in the same direction. This information showed that medicines treating these cancers should be prescribed separately rather than together, which is currently being done. In oncogenesis, the process of malignant transformation leading to the formation of a tumor, it was found frequently expressed in the cancer system that turn on specific amplifications. They examined 71 samples and able to narrow the amount of genes down using microarray, homology, validating them with RTPCR, and gene splicing with RNA. They found that siRNA successfully reduced expression of assays of mRNA resulting in the loss of function. Dr. Hummon and her research group was then able to identify nine genes that reduced the cell viability greater than twenty percent.

Many students seemed to enjoy this topic as well as the presentation. They listened attentively and asked many questions at the end, which were answered well. The presentation did encourage me to learn more about this topic and it would be appealing to do extra research on this topic, such as doing this same study or process with other tissues and organs. Dr. Himmon didn’t really speak much about her school of graduate studies, but I’m sure she would have been available to answer questions on that topic if asked. This was an interesting topic on the cancer cells and the genes involved dealing with colon and rectal cancer.

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This week’s speaker was Basar Bilgicer, who presented on multivalent antibodies. This speaker had was low voiced which made his presentation somewhat tough to follow. Bilgicer is a Chemical and Biomolecular engineer and was once a Harvard graduate, currently employed at Notre Dame University. This presentation went by quickly, but there was time towards the end when, Biglicer was able to answer any questions. I found this topic to be very interesting and I was able to learn many new things about antibody binding and other characteristics.

I learned that antibodies have avidity to binding from bivalency. Antibodies can be either monovalent or bivalent, in which they either bind one arm or both. They have a “Y” shaped structure in which there are two heavy chains and two light chains joined to form this shape. When an antibody binds with both arms the bond tends to be tighter or stronger. Biglicer researched the making of a synthetic antibody structure and wanted to make sure that this structure was tight binding, had a hapten structure that could be easily modified, commercially available, and a good price for making an antibody ligand pair. I also learned that the relationship between the monovalent and bivalent binding when dealing with enthalpy is the same. This happens due to the fact that although they are bivalent in bonding the arms would end up coming down at the same time yielding the same values as the monovalent ligand.

To give them a sense of the amount of binding/ binding strength that took place, they would plot the mole fraction against the ligand concentration as it increased. They also found that trivalent binding yielded more complex structures. In their research they wanted to form structures without steric hindrance and were excited that they found a ligand that could bind three arms of the antibody. At the end of their research they were able to find that bivalent and trivalent ligands promote stable aggregates of antibodies and that antibodies are bivalent since this increases the time of attachment, increasing production.

Many students seemed to enjoy the presentation and were very interested in learning more about antibodies. It’s interesting that pharmaceutical companies are trying to create more efficient antibodies than the ones in our bodies. There were many questions toward the end and Biglicer was able to answer them well. The presentation did encourage me to learn more about this topic, but not enough to do graduate research on it. Biglicer didn’t really tell much about attending his school of graduate studies, but he was available to answer questions about it. This presentation told of the binding properties of antibodies and their characteristics.

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This week’s speaker was a bioorganic scientist, Robert E. Minto. His presentation was understandable and he seemed to be very enthusiastic about the topic of lipid natural products and their diversity through a small change. The speaker didn’t have a thick accent which made his presentation easily heard. He also made sure to make eye contact with the audience and was able to answer the many questions that were asked after the presentation.

The topic was interesting and I didn’t know that there was such diversity among lipids. Some new things I learned were that there are eight standard lipids under the structural complexity of lipids. Some of these lipids include: pentanoic acid, palamatic, and steric acid. I also learned of the structure and significance of biologically active acetylenic natural products. Another new subject was where 2300 polyacetylenes could be found. They are found from three natural sources: plants, mosses and bryophytes, and fungi(mushroom like). During this presentation I was also fascinated by the plant that secretes cicutoxin, from the principle of the water hemlock. The oil inside this plant is very toxic, and can inhibit the potassium channel as well as shut down your central nervous system. Other things that weren’t tedious were that crepenynic acid desaturates fatty acids.

I think that there was mixed reaction to the speaker and presentation. Some seemed to enjoy it, while others looked as if they weren’t interested. There were a lot of questions asked during the question and answer period and the speaker was able to answer them well. Since I did not find this subject appealing to me, I was not encouraged to learn more about the topic. During the end of the presentation, Minto provided time to talk to students about his school of graduate studies. The presentation didn’t really fascinate me, due to the topic content, but there were parts that I felt were attention grabbing, such as the cicutoxin and its effects, I am interested more in the biochemistry portions of this presentation. This overall presentation was about the variety of lipids that are in natural products.

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This presentation was about certain implants for bone so that spinal fusion can occur. The speaker was Ryan. K. Roeder, a younger gentleman that discovered he had a passion in materials engineering. He works at Notre Dame, in the department of aerospace and mechanical engineering.

Currently his research involves processing structure property relationships in synthetic biomaterials and biological tissues. I found this topic to be very interesting.

During this presentation we learned that the biomaterials used in orthopedic implants consist of metals, ceramics, and polymers. Roeder believed that back pain was the number one reason people can’t work. His research consisted of developing a component that would cause bone to grow. They want to develop this component to be placed in between the space of the spinal bone. They have to make sure that this component is biocompatible as well as bioactive. We learned of the hierarchal structure of bone tissue and the ways they can be separated. Bone tissue is separated based on injection and absorbity. I also learned of HA whisker synthesis and that they used carboxylic acid binds the calcium ion so they can control the morphology of the crystal peek in crystal morphology. It was interesting how this process was found to suspend, isolate, and compress.

At the end of this presentation many students seemed to be engaged and really enjoyed the topics being discussed. During the question and answer period the speaker was able to answer all the questions and clarify information that students were confused on. Although I wasn’t encouraged to learn more about the topic or go to the speaker’s school of graduate studies, I found the information to be attention-grabbing. I felt that spinal fusion research is important and can benefit many people in the future.

This presentation was about research that will help solve people’s back problems by developing components that will help fill the space between the spinal bones.

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This week’s speaker was Jeffery A. Turk, an organic chemist who previously worked as a research scientist at International Flavors and Fragrances creating new aroma and chemicals. He spoke of design, synthesis and evaluation of novel enzyme inhibitors and fragrance molecules. I found his presentation style understandable but also quick. Turk was able to explain his work well and he made his presentation come alive by bringing samples of some fragrances.

The first thing that was mentioned which was new to me, was the fact that there are about fifty million olfactory receptor cells, and seven -transmembrane G-protein coupled receptors. The olfactory molecules contact the top of the protein receptors, and the olfactory receptors are tuned to chemical functionality, not odor properties. So when we smell certain odors it is due to certain molecules binding to certain olfactory receptors.

Other interesting facts included were that four hundred genes could code for a single olfactory receptor. There is also a link to the hypothalamus, in which went one smells something there is a part of the brain that lights up known as the olfactory bulb. One can also determine from OT, olfactory trackers, the amount of the molecule needed so that it can be picked up by the olfactory receptor. Since most fragrances come from trees, Turk is working to find other bases such as sandalwood and other new ingredients for which a variety of fragrances can be made. Turk’s goal is to find the reaction in which there is high atom efficiency with little waste and maximum yields. Some reactions that were tried were done with claisen rearrangement. I found the presentation very informative and liked that I was able to test out some of the fragrances made such as Ambrox and Carvone. What I found interesting about Carvone was that it had R and S enantiomers smelling of cinnamon and spearmint.

Many students seemed to enjoy this presentation and were very involved. During the end, Turk answered many questions very well. Although the presentation was appealing, I wasn’t exactly encouraged to do a seminar on this topic, it would be a good project to research on though. I was neither encouraged or discouraged to attend the speaker’s school for graduate studies, but this presentation about how we smell and how some of these molecules used in fragrances were synthesized, made me look at different fragrances in a new way.

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This week was a very interesting presentation in which, Jyllian Kemsley presented via a video conference. This was an experimental presentation done online, with the speaker in California and her presentation slides were on the screen next to her. Kemsley works as an associate science writer in Chemical and Engineering News. She has received a PhD in Chemistry from Stanford and it was there she found scientific writing to be interesting. Kemsley also provided us with a lot of information about her background. At Amherst College she became an chemistry major and worked as an analytical chemist after graduation. She entered the science writing program at UC Santa Cruz, and became a freelance writer and consultant.

In Chemical and Engineering News they produce feature stories, news items, online news, and blogs as well as perform story updates. In a typical week they read scientific papers, top of the news, converse with scientists and other sources, write, revise, and attend conferences near and far. They employ five or more editors and their goal is to produce good stories for readers. Although this is their goal there are still some challenges of science writing. One must be comfortable with unfamiliar territory, creative on demand, and juggle simultaneously different kinds of stories under different time pressures. Some rewards of becoming a scientific writer are: intellectual freedom, highly creativity, and flexibility in work hours and topic content. Kemsley has written stories on breast milk and nutrition and the influence it has on the infants, water plants mixing with sewage, and all types of things. If one is thinking of becoming a scientific writer they must have a fascination with science and a drive to keep learning.

In science writing, one can still work in traditional media, such as online media, trade publications, newsletters, science journals, etc. I thought it was very interesting that CNN laid off all of their scientific staff over the summer, so if one is thinking of doing scientific writing with a news media I suggest they also have a backup plan. Scientific writing is a good way to set up connections with industries, depending on what their topic of writing is about. Although I found scientific writing to be interesting and a good way of establishing networks, I wasn’t encouraged to do research in science writing. If one is thinking of becoming a science writer they can start be writing features for university publications, star ta blog, take classes in journalism, read widely (Knight Science Journalism Tracker), join the National Association of Science Writers, or attend annual science writers meetings.

I found that many students seemed to be engaged in this presentation and asked many questions at the end. Kemsley was able to answer the questions to the best of her ability and many students learned new things from this presentation. This presentation involved learning about science writing, and what one can do to achieve this goal.

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This presentation was done by a world famous organic chemist, Hiashi Yamamoto. Yamamoto had a mild Japanese accent and soft spoken, but his presentation was very understandable, in which he explained a lot. His current interests are cascade reactions for polyketide synthesis. I found this topic to be interesting and it was amazing that Yamamoto made up some of his own catalysts as well as reactions, such as the super bronsted acid, and the Sakuri reaction. Yamamoto started his presentation by giving a background of acid catalyst and telling of what he wanted to improve. His goal was to modify the acid making it more powerful, selective, and useful.

With the cascade reaction, they used a 1-pot reaction, in which a reactant is subjected to successive chemical reactions in just one reactor. The importance of polyketides are that 1% of them are biologically active, which is five times the average for natural products. Another interesting point was the Mukaiyama Aldol reaction, which can be key for the synthesis of Nyastatin A., Leucascandrolide A, and Tetrafibricin. These methods are three to four steps and were improved by changing the acid catalyst to a super bronsted acid or silyl acid, which are very strong. Yamamoto and his group also performed an excess aldol reaction to see if they can form molecules with large molecular weights. They found that they could make a trialdol, using an iodine benzene complex. This molecule has three chiral centers, making it possible to generate eight stereoisomers of one product. They also performed a sequential reaction from acid to basic in a one pot reaction which I thought was very interesting.

At the end of this presentation many questions were asked, and Yamamoto answered them well. Some students seemed to enjoy the presentation, while others looked as if it was tedious towards the end. I felt that the overall presentation was appealing and I learned a lot about cascade reactions.

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Michael Velbel is a professor of geological sciences at Michigan State University. Velbel presented on the microscopy and geochemistry of natural waters. Under this topic he, informed us about some reactions that take place during the weathering of the rocks. Velbel kept students interested by adding humor to his presentation and relating with the audience. The presentation was understandable and very interesting. Velbel also made eye contact and did not hesitate to answer the questions of the students in the end.

Some interesting points learned during this presentation dealt with hillslope hydrology, coweeta water sheds, Na-feldspar weathering, and the role of microscopy with these reactions. Hillslope hydrology addresses the role and function of watersheds at the plot-hillslope catchment scale. It helps scientists discover where the water goes when it rain, how long it residues in a watershed, and what pathway the water takes to the stream channel. Using this method Velbel was able to see that the water flowed down through mineral and geologic material and then came out as stream water. The Coweeta watersheds measured the flux of elements going in the rain and the amount was able to be determined by removing it from the rain water. With the watersheds Velbel’s group was able to combine and balance the stoichiometric weathering reactions. With Na-feldspar weathering the feldspar would turn into kaolinite plus dissolved materials (ions). All occurred in the solid form and none in the liquid form. If the feldspar came in contact with acid and water it would readily turn into clay. The reaction can be sped up with an increase in temperature and an acid. The role of microscopy was to constrain how reactions should be written and it showed how the feldspar dissolved into its other states.

The conclusion that Velbel stressed at the end was, studying materials and their reactions with aqueous solutions improves the understanding of many phenomena on earth and elsewhere in the solar system and beyond. I thought this to be very interesting and many students were engaged especially when Velbel brought up the subject of NASA, and the work that Velbel’s group would like to see done on Mars. The overall presentation was satisfactory, and it would be interesting if they found out about pyroxene corrosion being present on Mars.

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Adam J. Matzger spoke of storing hydrogen and capturing carbon dioxide. Matzger received his BA degree in 1992 from Oberlin College, Ohio. While working on his Ph.D., Matzger conducted theoretical and experimental investigations of dehydrobenzoannules and phenylenes. Matzger is currently researching organic materials in the solid state ranging from crystalline polymorphs to porous materials. One-thirtieth of an ounce of the saltlike zinc oxide crystal that Matzger developed has enough surface area to cover an entire football field. Scientists say that highly porous materials like this could eventually store hydrogen for cars, pull planet-warming carbon dioxide out of the air and remove noxious sulfur compounds from hydrocarbon fuels.

During the presentation Matzger was loud, enthusiastic, made eye contact, and allowed questions during the presentation which kept the audience awake and interested. Some interesting facts learned were the synthesis of Mof-5 which was a crystalline high surface area material that stored hydrogen. Other fun facts were the demands for a hydrogen storage system. They must be high gravimetric and volumetric capacity, heat adsorption either too high or low would need good kinetics of uptake/release of hydrogen. The surface area was also directly related to the amount of hydrogen that was absorbed.

Hydrogen was also being used as fuel storage material, but problems arose. It was not an energy-dense fuel, and in its liquid form although its energy density increased, there was a need for low temperatures and high pressures. Other parts of the presentation included the capturing of carbon dioxoide from coal fired plants. The  carbon dioxide is removed after the combustion of the fossil fuel, captured from flue gases at power stations or other large point sources. In the sorption process magnesium was the best in capturing the carbon dioxide. Sorption is a common term for absorption, in which a substance of one state is incorporated into a different state. This process is reversible and by just changing the pressure carbon dioxide can either be absorbed or desorbed. This presenter did not go over time as did previous presenters and students engaged in many questions during the question and answer period.

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Sean Reed received a bachelors of science in chemistry and psychology at Iowa State University in 2005. In 2006, Reed began graduate studies at the University of Illinois, Urbana-Champaign, under the direction of Assistant Professor M. Christina White. Reed’s research includes intermolecular C-H animation and the strategic application of C-H activations reactions in complex molecular synthesis. This research has led to new, more efficient reactions that allow chemists to significantly shorten the total synthesis of natural products.

Reed was very prepared with many handouts of the research conducted and gave background to the experiments being discussed. I felt that this gave a good introduction of the information he was about to relay. Although the presentation had to be cut short, Reed was able to give a sufficient amount of information on C-H animation and the reason why these experiments were being performed.

Some of Reed’s goals for this research were to discover new pharmaceutical products, develop reactions that will make another molecule, perform functional group transformations, work with C-C bond formation, and achieve olefin oxidation. In allylic/aliphatic selective C-H oxidations for synthesis use metal oxo, nitrenes, and carbene catalysts. It was found for allylic C-H animation if one removed the metal catalysts, containing Pd and Cr(salen)Cl, then there was no reactivity for these reactions. Reed was able to learn what the reaction needed in order to work. It was also found that an n-allylPd intermediate was formed.

Another thing that I felt was interesting was the work being done with streamlining synthesis. Reed along with his group have previously demonstrated the ability of predictably selective C-H amination reactions to streamline the synthesis of nitrogen containing molecules. Students seemed tired by the end of this presentation, but we learned much and our questions were answered well.

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The speaker was Carolyn Anderson, from Calvin College in Grand Rapids Michigan. She received her bachelor’s degree in Chemistry from the University of Michigan in 1988. She also received a Ph.D. in organic chemistry at the University of California at Irvine in 2003.

Anderson’s research program develops methods for the synthesis of molecules of pharmacological or inherent interest. Currently her research is specifically focused on developing new synthetic methodologies for preparing N-alkyl pyridones, including amino acid homologues.

Anderson was the first woman speaker of this year. She made eye contact with the audience, and in a fast fashion she showed many mechanisms. The topic of this presentation was basically applied research in finding out how alkyl pyridones are prevalent in natural products and they have a potential use as an amino acid mimic.

Some things I learned during this presentation were the importance of N-Alkylated pyridones which is selective ligand for the CB2 receptor. These pyridones are also seen as a potential tissue factor. For microwave studies, these reactions to form N-alkylated pyridines also form a benzylacetamide by-product. In optimization studies, it was found that the reaction worked better at room temperature. The limitations of this experiment were that the substitution on the alpha position significantly slows the rate of migration. A good thing that was learned throughout this experiment was that electron withdrawing groups also increase the reaction rate. In propargylic migration, the migration rate is slower than in the benzyl case.

The overall conclusion for this presentation was that Anderson has developed new oxygen to nitrogen alkyl migration strategy for the preparation of the N-benzyl and N-propargylic pyridones.

Many students asked questions and the speaker answered to the best of her ability, helping the students to better understands the material.

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This week’s speaker was Silas Cook, a synthetic organic chemist, currently at Indiana University. He did undergraduate studies at Reed College in Portland, OR. While doing his studies he recognized the importance of organic chemistry in a wide range of disciplines from cell biology to nuclear chemistry. Cook’s research focuses on the synthesis of biologically relevant small molecules inspired by complex natural products. His work seeks to uncover new strategies in synthesis, catalysis, and molecular pharmacology.

Cook specializes in total synthesis, which deals with making molecules nature’s already made and methodology, which deals with figuring out new reaction conditions to develop new products. For example a + b= c, then you find out that a +b = d.

During the presentation, Cook made eye-contact with the audience, was very informative, and spoke in an understandable way. He would also ask questions and give out prizes which kept things interesting and people from falling asleep. The topic was very interesting and brought back memories of the mechanisms and reactions I learned in organic chemistry.

Some new things I learned were the goals of total synthesis: to synthesize much needed molecules, demonstrate the limitations of current methods, highlight new methods in a complex setting, and train outstanding synthetic chemists. There are also some therapeutic areas of interest: oncology, antibiotics, neurological disorders, and Third World ailments, meaning malaria, chagas, e.t.c.

Cook was once working on Artemisinin which is the best malaria treatment, which is now produced via semi-synthesis from plant materials. Then his group became interested in neurotrophic factors that are responsible for the growth, maintenance, and survival of neurons. It was thought that they may be a key in treating neurodegenerative diseases such as Alzheimer’s and Parkinsons. Nonpeptidyl small molecule neurotrophic factor mimetics have the potential of avoiding these pitfalls. While they still feature neurotrophic activity, they may also be orally bioavailable, blood-brain barrier permeable, and more specific in their target receptor activation. One such small molecule is 11-O-debenzoyltashironin. When working with this molecule, Cook went through various reaction sequences to find the one that gave the desired results.

The desired result was to succeed in isolating the 11-O-Debenzoyltashironin from the ester. He used many methods: Retrosynthetic Analysis, Phenol Synthesis, Alkene Diels-Alder, Aromatic transformation, and an enol ether approach. This whole process took about five years, showing that Cook was very dedicated and hardworking. This topic also made me wonder if there are any molecules that are closely related to 11-O-Debenzoyltashirionin or even artemisinin that performs close to same performance and has been found to have any effect on the diseases mentioned. Are there different conformations of this molecule that may give adverse effects?

During the question and answer period, Cook was able to answer the questions well, and many students enjoyed this presentation, and seemed to be interested in learning new things about the topic.

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This week’s presentation by Wendel P. Griffith, talked of Hemoglobin, hemoglobin binding proteins and its relation to mass spectrometry. Griffith is a Analytic Chemist, specializing in Hemoglobin. He did his undergrad work at Grambling State University, LA then completed a PhD in Analytical Chemistry at the University of Massachusetts. This speaker was very enthusiastic, informative, and made eye contact with the audience. I could see that he was passionate about his research, and related it to everyday life. Griffith can present very clearly, putting away his Trinidadian accent.
I learned much about mass spectrometry, hemoglobin, and the interaction between band 3 and hemoglobin. Mass spectrometry is a color blind spectroscopy, fine separation technique, and gas- phase electrochemistry. It vaporizes analytes, ionizes them, and then analyzes them according to their mass to charge ratios. It is composed of an ion source, mass analyzer, and detector. The Griffith then explained how the ion source converts gas phase sample molecules into ions, which then move into a mass analyzer which sorts the ions by their masses, and a detector which measures the values, calculating the abundance of each ion present. He then broke down this concept by using an example in which you have two people of different masses ingesting a power bar, then running a race. Who gets there first? The person with the smaller mass will get there first, since the power bar can pass through more quickly. This is the way ions travel to the detector, the “time of flight” concept.

Other things learned were some facts about hemoglobin chains. The alpha and beta chains of hemoglobin are coded by different chromosomes in hemoglobin. Alpha globin provides a “rigid” template for assembly in hemoglobin. The beta globin is flexible (intrinsically disordered) for the efficient accommodation of the alpha globin. Intrinsic disorder is important in the large scale chain dynamic, conformation, and asymmetry in the assembly process of hemoglobin.

Griffith is currently studying the characterization of haptoglobin-hemoglobin interactions using mass spectrometry. He is also researching a toxin that can kill bacterial meningitis. Many students were intrigued by these concepts, and hardly fell asleep. During the question and answer period not many students asked questions since the speaker explained everything well. Some questions to ponder are: What is the estimated life of bacteria in bacterial meningitis? When blood is donated, do the red blood cells have a different estimated life then in the body (120 days)? Why is crystallography and fluorescence not as effective as mass spectroscopy when dealing with hemoglobin?

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The speaker, Dr. Matthew J. Allen had a presentation style that was both informative and understandable.  Allen is an assistant professor of chemistry at Wayne State University. The topic that Prof. Allen presented on was “Increasing the Utility of Contrast Agents for Magnetic Resonance Imaging using Lanthanide Chemistry.”

The first thing I thought was that’s a long title, but as Allen presented I found the information very interesting. I learned many new things dealing with the comparisons of MRI, X-ray, and positron emission tomography. I have family that works in the operating room and deal with these instruments daily, but I never knew what was actually used in order to get a clear picture of the tissue. X-ray and positron instruments use a lot of radiation so that deep inside the tissue can be seen. The MRI instruments use water proton relaxation times in order to get pictures deep inside tissue. Currently, contrast agents are used to improve MRI images but have some limitations.

The lanthanides, used in MRI imaging, have unique optical and magnetic properties. They usually are found in the +3 oxidation state, which is when they are most stable. Another lanthanide, apart from Gd +3, that Allen is studying for higher frequency MRIs is Eu +2.   However, this ion needs to be stabilized against oxidation. Luminescence decay studies show this reaction is proceeding. So questions that I pondered after the presentation were: How do luminescence decay studies show the reaction is proceeding? Can other methods be used to see/determine how the reaction is proceeding?  Why was Eu (II) chosen to replace Gd (III) at higher magnetic fields? Why not another lanthanide? Why Eu+2?

The overall presentation was interesting and research is still being done.

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