Past Planalp Group Students… Where are they now?
Leonid Povolotskiy
Previous work:
I worked on the synthesis of various bifunctional fluorescent intracellular iron chelators. Through a series of organelle targeting peptides, we hope to explore labile iron metabolism at a subcellular level. I work predominantly on the synthesis of targeting peptides and work closely with Ryan Fitzgerald who handles much of the ligand synthesis. We are looking to combine our respective components to create a functional intracellular iron probe.
Leo graduated with his doctorate in 2023.
Previous Research:
My undergraduate work revolved around elucidating the mechanism of non-selenocysteine containing thioredoxin reductase enzymes. This work was conducted at the University of Vermont with Dr. Rob Hondal. It was there that I received much of my training in peptide synthesis and focused primary on the preparation of strained disulfide rings.
Presentations:
Bifunctional Iron Chelators and Their Fluorophore Conjugates for Study of Cellular Iron Metabolism; GDCh frühjahrssymposium Poster Presentation Spring 2021.
Interests:
I joined the Planalp group in the spring of 2019 to start work on the bio-inspired ferroptosis project. I enjoy a sense of comradery in this group that I have not experienced in a long time. My interest in chemistry lies in bio-inspired and medicinal chemistry. Outside of the lab I enjoy the skiing and hiking the White Mountains. This part of New England has offered me excellent chances to enjoy all the things the great outdoors has to offer.
Favorite Thing to Do on Campus:
Going on a lovely stroll in College Woods with my dog.
Contact: lp2005(at)wildcats.unh.edu
Noah Cote
Previous work:
I worked on the design, synthesis, and characterization of Zr4+ and Sc3+ based bifunctional chelators with improved in vivostability. These radioisotopes have shown to be effective Immuno-Positron Emission Tomography (PET) agents. To model these complexes, geometry optimizations using Gaussian 09 software are being employed to unveil the potential of phosphinate ligands for Zr4+ binding. I am currently working to prepare a Sc3+ based bifunctional chelator that incorporates these phosphinate moieties. I am the only member currently working on this project, so I consider this a unique opportunity.
Noah finished his masters in 2022, see his thesis here.
Past Research:
My undergraduate senior thesis work was performed at University of New Hampshire, Durham under Dr. Arthur Greenberg. This research aimed to model the ring-opening metabolism benzene takes within the liver using 2,3-benzoxepin and 4,5-benzoxepin as substrates. These substrates were exposed to 1A2 isoforms of cytochrome P450 as well as two consecutive one electron oxidation using cerium ammonium nitrate (CAN) for comparison.
Publications and Presentations:
Weaver-Guevara H.M., Fitzgerald R.W., Cote N.A., Greenberg A. Cytochrome P450 Can Epoxidize an Oxepin to a Reactive 2,3-Epoxyoxepin Intermediate: Potential Insights into Metabolic Ring-Opening of Benzene. Molecules. 2020; 25(19): 4542.
Synthesis of Model Oxepin Substrate 2,3-Benzoxepin for Benzene Metabolic Mechanistic Studies with m-Chloroperbenzoic Acid, Cerium (IV) Ammonium Nitrate, and Cytochrome P450; Spring 2019 Northeast Section Younger Chemist Committee.
The Preparation of Modified DFO for Positron Emission Tomography; Fall 2019 Boston Regional Inorganic Colloquium.
Interests:
I joined the Planalp research lab in Summer 2019. Despite synthetic difficulties, I could not envision a better group to be working for. Currently interested in the intercrossing of inorganic chemistry and biological systems to be used for pharmaceutical purposes. I find the combination of synthetic inorganic chemistry and biological systems to be rather fascinating. Metals are proven to have incredible medicinal potential that we as humans could not provide without them. Designing and synthesizing a sustainable pathway that incorporates such metals to tackle some of the worlds most challenging health issues is a current dream of mine. Outside of chemistry, I enjoy hiking, relaxing lakeside/beachside, and visiting local craft breweries.
Favorite thing to do on campus:
Walking around College Woods or eating any of the awesome food on campus.
Contact: nac1009@wildcats.unh.edu
Ryan Fitzgerald
Previous work:
I have worked towards a hydroxyquinoline-based hexadentate chelator with the ability to bind either Fe2+ or Fe3+ for iron sequestration in the mitochondria of a cell. This chelator will be attached to a lysine residue of a SS-peptide sequence which has been shown to target the mitochondria. This molecule is being made using a convergent approach where my colleague Leo Povolotskiy is designing the peptide at the same time as I am the chelator to be linked together via an amide bond.
Ryan graduated with his doctorate in 2022, see his dissertation here.
Past Research:
Before joining the Planalp lab, I worked on modeling benzene metabolism for Dr. Arthur Greenberg at UNH (B.S. University of New Hampshire). Benzene has a well characterized metabolic pathway to phenolic metabolites from epoxidation via cytochrome P450 in the liver but there is a less well-known valence tautomerization of intermediates benzene oxide and oxepin. We set out to elucidate the mechanism by which oxepin ring opens into E,E-muconaldehyde through either further epoxidation or two consecutive single electron oxidations.
Other projects I worked on in the Greenberg lab include attempted synthesis of novel strained lactams containing silicon known as silatranones as well as rotational barrier measurements on various tertiary amides using variable temperature NMR.
Publications and Presentations:
Synthetic Advances toward a Bifunctional Tripodal Chelator Framework; 52nd Boston Regional Inorganic Colloquium (Virtual at UNH) Spring 2021.
Weaver-Guevara, H.M.; Fitzgerald, R.W.; Cote, N.A.; Greenberg, A. Cytochrome P450 Can Epoxidize an Oxepin to a Reactive 2,3-Epoxyoxepin Intermediate: Potential Insights into Metabolic Ring-Opening of Benzene. Molecules. 2020, 25(19), 4542.
Synthesis of Model Oxepin Substrates for Benzene Metabolic Mechanistic Studies with Dimethyldioxirane, Cerium (IV) Ammonium Nitrate, and Cytochrome P450; UNH Graduate Research Conference Spring 2019.
Weaver-Guevara, H.M., Fitzgerald, R.W., Greenberg, A. Rotational barriers in five related amides. Canadian Journal of Chemistry, 2017, 95, 3, 271-277.
Morgan, J.P., Weaver-Guevara, H.M., Fitzgerald, R.W., Greenberg, A. Ab initio computational study of 1-methyl-4-silatranone and attempts at its conventional synthesis. Struct Chem. 2017, 28, 327–331.
Interests:
I joined the Planalp lab at UNH in the spring of 2019. The Planalp lab is a fun, productive working environment. I am very interested in medical or environmental research that has the potential to help people. My new group has given me the opportunity to learn more about inorganic chemistry and ligand design that both have applications for designing a CO2 reduction catalyst or toxic metal binding in the body. I really enjoy organic synthesis, physical organic chemistry, and catalysis. Ligand design involves a lot of well-planned organic synthesis which is fun to combine with the skillsets of my colleagues.
Favorite thing to do on campus:
I really enjoy playing basketball at UNH Hamel Rec Center and all the various outdoor courts on campus. There are also lots of great places to eat in Durham that I enjoy including Wildcat Pizza, Bamee, Thai Smile 2, and Pauly’s Pockets.
Contact: rwj9(at)wildcats.unh.edu
Luke Fulton, PhD
Previous work:
My previous project involved exploring sensor arrays for biologically relevant metal ions in aqueous media.
Luke graduated with his doctorate in 2019, see his dissertation here.
Interests:
I’ve long been captivated by the varying tools and approaches developed within the different branches of chemistry. This made joining the Planalp group a great boon as our research lies at the junction of the Inorganic and Analytical disciplines. This environment allows me to pursue chemical applications to practical needs through synthetic design.
Lea Nyiranshuti, PhD
Current work:
Lea graduated with her doctorate in 2017, see a recent article on Lea’s success.
Previous work:
1) Design, synthesis and characterization of pyridine based ligands that have high affinity toward Cu(II). Determination of binding affinities with Cu(II) and other selected divalent metal ions using potentiometric titration. Synthesized ligands are incorporated in a polymer system for synthesis and characterization of a ratiometric fluorescent sensor for Cu(II).
2) Design, synthesis and characterization of ligands for sensing metal ions present in intracellular and extracellular environment.
Past research experience:
My previous research experience includes undergraduate senior research that I did at University of California, Riverside with Dr. Dallas Rabenstein about synthesis of new peptides used for neutralization of anticoagulant activity of Heparin. After my undergraduate education, I worked as an intern at Pfizer Global Research & Development in La Jolla, CA. At Pfizer, I helped to study toxicity of several drugs and developing new ways to detect cancer cells at early stage by using biomarkers. It was during my time at Pfizer that I developed interest in “biosensing” and “bioimaging”. My overall research interest includes design and synthesis of novel small molecules for sensing metal ions in intracellular and extracellular environment.
Mahmoud Abdalrahman, PhD
Previous work:
I have been working on two projects in the Planalp group. The first project involves the synthesis of a polymerizable terpyridine ligand that can be incorporated into our copper sensor polymer. In my other project, I synthesize metal-ligand complexes concentrating on copper, and I characterize the complexes via single crystal X-ray diffraction, in order to understand and optimize the affinity of the ligands towards copper.
Mahmoud graduated with his doctorate in 2017, see his dissertation here.
Interests:
Growing X-ray quality crystals of metal-ligand complexes and solving their structures for environmental and biological applications.