The Johnson Group recently completed an asymmetric synthesis of the squalene synthesis inhibitor zaragozic acid C. The synthesis featured an interesting controlled oligomerization cascade to establish much of the stereochemically and functionally complex core. More broadly, the work asks if the lessons of polymer synthesis can be applied in the realm of natural product synthesis through the application of tailor-made reagents with the appropriate trigger. This work was highlighted in Science and Chemical and Engineering News.
Research in the Hicks Group focuses on development and implementation of mass spectrometric approaches for protein characterization including post-translational modifications, as well as the identification of bioactive peptides/proteins from plants.
Assistant Professor Brian Hogan has been honored for his recent graduation from the Carolina Center for Public Service's Thorp Faculty Engaged Scholars program. Brian was one of nine members of the Thorp Faculty Engaged Scholars, FES, Class IV who worked over the past two years to strengthen partnerships between the University of North Carolina at Chapel Hill and the surrounding community.
The program, an initiative of the Carolina Center for Public Service, brings together selected faculty from across campus to engage in a two-year experiential, competency-based curriculum designed to advance their scholarship. Scholars participate in sessions in community settings to learn from Carolina faculty and their community partners and build relationships through work such as training teachers to integrate experiential learning into their classrooms. Brian is the academic director for the Scholars' Latino Initiative, a program dedicated to increasing college access for Latino high school students. He helped build "SLIence," a collaboration between McDougle Middle School and the Scholars’ Latino Initiative.
Carolina Chemistry Professor Maurice Brookhart has been selected to receive the 2015 Gabor A. Somorjai ACS National Award for Creative Research in Catalysis. The award recognizes outstanding theoretical, experimental, or developmental research resulting in the advancement of understanding or application of catalysis, and consists of a $5,000 cash prize along with a certificate and up to $2,500 for travel expenses to the meeting at which the award will be presented.
Professor Brookhart was recently highlighted by the National Science Foundation for his ground-breaking contributions to the improvement of the process used to create alternative fuels. He is part of a team of scientists who have invented and patented, and are bringing toward commercialization, catalysts that will convert light hydrocarbons into diesel fuel. The improved process can create diesel in a less expensive, cleaner way, whether it is diesel made from traditional sources, such as oil, or alternative sources, such as biomass.
Dr. F. Ivy Carroll, member of Carolina Chemistry's External Advisory Board, has been recognized by the American Chemical Society as a 2014 ACS Fellow. He is honored for his contributions to science, including the design and development of a diagnostic agent for Parkinson's disease and compounds as potential treatments for cocaine and nicotine addictions and other central nervous system disorders. He is also recognized for his long service to ACS.
Dr. Carroll is a Distinguished Fellow in medicinal chemistry with RTI International, which he joined in 1960. He has published more than 440 peer-reviewed publications, 34 book chapters, 43 patents, and more than 20 current patent applications. Among his many awards and recognitions are the 2010 North Carolina Award for Science, and the 2010 National Institute on Drug Abuse Public Service Award for Significant Achievement.
Dark-field microscopy, DFM, is widely used to optically image and spectroscopically analyze nanoscale objects. In a typical DFM configuration, a sample is illuminated at oblique angles and an objective lens collects light scattered by the sample at a range of lower angles. As demonstrated in an article published as the cover of ACS Photonics, researchers in the Cahoon Group have developed waveguide scattering microscopy, WSM, as an alternative technique to image and analyze photonic nanostructures. WSM uses an incoherent white-light source coupled to a dielectric slab waveguide to generate an evanescent field that illuminates objects located within several hundred nanometers of the waveguide surface.
Using standard microscope slides or coverslips as the waveguide, the group demonstrate high-contrast dark-field imaging of nanophotonic and plasmonic structures such as Si nanowires, Au nanorods, and Ag nanoholes. Scattering spectra collected in the WSM configuration show excellent signal-to-noise with minimal background signal compared to conventional DFM. In addition, the polarization of the incident field is controlled by the direction of the propagating wave, providing a straightforward route to excite specific optical modes in anisotropic nanostructures by selecting the appropriate input wavevector. Considering the facile integration of WSM with standard microscopy equipment, the Cahoon Group scientists anticipate it will become a versatile tool for characterizing photonic nanostructures.
The direct anti-Markovnikov addition of strong Bronsted acids to alkenes remains an unsolved problem in synthetic chemistry. Published in Nature Chemistry, researchers in the Nicewicz Group report an efficient organic photoredox catalyst system for the addition of HCl, HF and also phosphoric and sulfonic acids to alkenes, with complete regioselectivity. These transformations were developed using a photoredox catalyst in conjunction with a redox-active hydrogen atom donor.
The nucleophile counterion plays a critical role by ensuring high reactivity, with 2,6-lutidinium salts typically furnishing the best results. The nature of the redox-active hydrogen atom donor is also consequential, with 4-methoxythiophenol providing the best reactivity when 2,6-lutidinium salts are used. A novel acridinium sensitizer provides enhanced reactivity within several of the more challenging reaction manifolds. Thew work published by the Nicewicz team demonstrates how nucleophilic addition reactions mediated by photoredox catalysis can change the way electrophilic and homofugal precursors are constructed.
The synthesis of prodrugs is a common approach to overcome drug delivery issues, including poor aqueous solubility or permeability, and to provide site-specific release. Nanotechnology can be a powerful tool to improve drug delivery, but does so by altering the biodistribution of the encapsulated small molecule. In a report published in NanoLetters, researchers in the DeSimone Group, in collaboration with a number of Centers, Institutes, and Departments here at UNC, combined the merits of both approaches to improve the pharmacokinetics and toxicity of the chemotherapeutic docetaxel by passively targeting an encapsulated docetaxel prodrug to solid tumors, where it could selectively release and convert to active docetaxel.
The Group used PRINT technology, Particle Replication in Nonwetting Templates, to prepare nanoparticles to passively target solid tumors in an A549 subcutaneous xenograft model. An acid labile prodrug was delivered to minimize systemic free docetaxel concentrations and improve tolerability without compromising efficacy.
At the Department of Chemistry, we feel strongly that diversity is crucial to our pursuit of academic excellence, and we are deeply committed to creating a diverse and inclusive community. We support UNC's policy, which states that "the University of North Carolina at Chapel Hill is committed to equality of opportunity and pledges that it will not practice or permit discrimination in employment on the basis of race, color, gender, national origin, age, religion, creed, disability, veteran's status, sexual orientation, gender identity or gender expression."