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The Joseph A. Dixon Travel Award Spring 2002 ACS Meeting, Orlando FL
Progress In The Synthesis Of 1,5-Methylenesemibullvalene Two steps have been performed in the synthesis of 1,5-methylenesemibullvalene: (1) oxidation of [3.3.1] propellane-2,8-dione with selenium dioxide and (2) reduction using sodium borohydride. Diisobutylaluminum hydride (DIBAL) is also being investigated for the the reduction. The next step is (3) a bromination using phosphorus tribromide. [3.3.1] Propellane-2,8-dione was prepared in five steps, thus the synthesis of the semibullvalene is completed in nine steps. With further progress only one step remains in the synthesis, (4) a cyclization/debromination, which will be completed by following literature precedent for other semibullvalenes, including the use of a zinc-copper couple or nickel carbonyl.
Celebration of the ACS 125th Anniversary at Priestley House On October 14, 2001, about 150 ACS members representing the Central Pennsylvania, Lehigh Valley, and Susquehanna Valley Sections met at Priestley House in Northumberland, PA, to celebrate the 125th anniversary of the ACS. Much of the history of the American Chemical Society is intertwined with the history of Priestley House. In 1874, the first national congress of American chemists was held in Northumberland on the Centennial day of Priestley's discovery of oxygen – a meeting which inspired the founding of the ACS two years later. Attendees of the 2001 celebration re-created the train ride taken by ACS members from Philadelphia to Northumberland in 1926 on the Society’s 50th anniversary celebration. Gold and bronze replicas of the Priestley medal were presented and a "parade of red roses" was made to Priestley’s gravesite. Undergraduate students in the Penn State Nittany Chemical Society held a chemistry trail of hands-on experiments for children and performed demonstrations for all to enjoy. Comparison of affinity tagging systems to efficiently purify
proteins and protein complexes Affinity tags provide powerful methods for protein purification. We have evaluated efficient affinity tagging systems to purify recombinant fusion proteins from Escherichia coli. This study involved cloning and over-expressing a double-fusion tag model consisting of TAG-6xHis-enzyme, in which the TAG was varied between plasmid constructs, and the 6xHis-enzyme fusion remained constant. Affinity TAGs that were analyzed included calmodulin binding peptide (CBP), Strep-tag, HPC4 epitope, and FLAG. The 6xHis tag served as a reference tag to compare purity using the commonly used cobalt-affinity resin. The enzyme dihydrofolate reductase (DHFR) was used to determine of the efficiency of the different tagging systems through quantifying the recovery of active, non-aggregated protein in a simple photometric assay. After successful assessment and development of one or several affinity purification systems, we plan to use the most efficient affinity tags to purify recombinant complexes from Escherichia coli or native complexes from Saccharomyces cerevisiae. Outreach and the Nittany Chemical Society In recent years public outreach has become the main focus of activity for the Nittany Chemical Society. Each year several chemical outreach events are held for members of the local community. During the Halloween season NCS presents a Magic Show for an audience of all ages. In the spring the main outreach event is the Nittany Chemistry Trail which is presented during the children’s festival at a local mall. The chemistry trail contains a number of hands on activities for young children including smashing flowers frozen in liquid nitrogen, the luminescence chamber, and making gak. In addition to these events, many NCS members also volunteer time in local K-12 science classrooms and serve as councilors for summer science camps held on the Penn State Campus. Structural and chemical characterization of closed coral reef
ecosystems It has only been within the last 20 years that corals have been successfully grown in aquaria for extended periods of time. These closed ecosystems allow scientists with the opportunity to study corals within a controlled environment. In 1999, a public aquarium exhibit, including a 530 gallon coral reef tank, was established in the Penn State student center. This public aquarium is also used for research purposes and allows for the investigation of tropical marine ecosystems to take place in a location remote from the ocean. Several imaging techniques, including scanning electron microscopy and x-ray topography scanning, have been used to explore the structural characteristics of the aragonite-based coral skeleton. Further experiments are aimed at understanding the effect of phosphate pollution caused by agricultural runoff on natural reefs. 31P NMR of solid coral samples and liquid extracts provides insight into the incorporation of phosphate in corals while chemical analysis provides compositional information on the absolute amounts of phosphate and other coral skeletal components such as calcium, strontium, and magnesium. |
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