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关键词： Second-Year Undergraduate   Laboratory Instruction   Organic Chemistry   Nucleophilic Substitution   Ethers   Collaborative/Cooperative Learning   Hands-On Learning/Manipulatives   Student-Centered Learning   Inquiry-Based/Discovery Learning   Problem Solving/Decision Making  

摘要： An inquiry-based experiment for the organic chemistry laboratory was developed to provide students with a cognitively rich research experience. Student teams were charged with optimizing the reaction conditions for the Williamson ether synthesis of 2-fluorophenetole from 2-fluorophenol, ethyl bromide, and potassium carbonate in either absolute ethanol or acetonitrile. Microwave acceleration of this S(N)2 reaction followed by rapid GC-MS analysis allowed students to review results, revise experimental conditions, and repeat the modified reaction and its analysis within a 3 h laboratory period. Variables that could be manipulated were reagent equivalencies, solvents and their volume, microwave reaction time, temperature, and wattage. Post-laboratory, all team data were available to the entire class for additional evaluation and each student was required to suggest new conditions for improvement in his/her laboratory report.

关键词： Medicinal Chemistry   Internet/Web-Based Learning   Testing/Assessment   Organic Chemistry   Applications of Chemistry   Interdisciplinary/Multidisciplinary   Drugs/Pharmaceuticals  

摘要： A molecule of the month extra credit assignment was introduced to a didactic introductory pharmacology and medicinal chemistry course for first-year pharmacy students. The structure of a clinically approved drug molecule was presented to students each month of the course after the first month. Students would answer questions pertaining to the name of the drug, its mechanism of action, specific aspects of its chemistry, and the indication(s) it is used in. Mean and median course scores were compared between classes of students who undertook molecule of the month questions and classes that did not. Extra credit earned from molecule of the month questions could not be applied to failing scores. Students overwhelmingly participated (85-96%) in answering molecule of the month questions. Students who had the molecule of the month questions available performed significantly better than those that did not. The number of students receiving a final course score >91% increased more than 3-fold, and no students attained a failing score (<70%). The improvement in student final course score (average increase of 7%) far exceeded the 3% extra credit available for answering molecule of the month questions.

关键词： General Public   Second-Year Undergraduate   Laboratory Instruction   Organic Chemistry   Laboratory Computing/Interfacing   Computer-Based Learning  

摘要： Electronic laboratory notebooks are gaining in popularity in industry and academia. Various types of electronic laboratory notebooks exist, and a variety of tools can be used for these forms of notebooks. Some tools are commercial products dedicated to being electronic notebooks, while individual organizations can develop ones for their own needs with tools such a OneNote and Google Docs. Google Docs was used as an electronic notebook in organic chemistry, and student perceptions were evaluated using surveys. These tools are used to reduce students' time preparing for lab and writing reports. The implementation of the notebooks and the findings of students' perceptions on the implementation are discussed.

关键词： Impurities   Peptides and proteins   Drug discovery   Chemical synthesis   Bioactivity  

摘要： Residual complexity (RC) involves the impact of subtle but critical structural and biological features on drug lead validation, including unexplained effects related to unidentified impurities. RC commonly plagues drug discovery efforts due to the inherent imperfections of chromatographic separation methods. The new diketopiperazine, rufomyazine (6), and the previously known antibiotic, rufomycin (7), represent a prototypical case of RC that (almost) resulted in the misassignment of biological activity. The case exemplifies that impurities well below the natural abundance of C-13 (1.1%) can be highly relevant and calls for advanced analytical characterization of drug leads with extended molar dynamic ranges of >1:1,000 using qNMR and LC-MS. Isolated from an actinomycete strain, 6 was originally found to be active against Mycobacterium tuberculosis with a minimum inhibitory concentration (MIC) of 2 mu g/mL and high selectivity. As a part of lead validation, the dipeptide was synthesized and surprisingly found to be inactive. The initially observed activity was eventually attributed to a very minor contamination (0.24% [m/m]) with a highly active cyclic peptide (MIC similar to 0.02 mu M), subsequently identified as an analogue of 7. This study illustrates the serious implications RC can exert on organic chemistry and drug discovery, and what efforts are vital to improve lead validation and efficiency, especially in NP-related drug discovery programs.

关键词： mobile NMR instruments   NMR relaxometry   NMR spectroscopy   nondestructive testing   reaction monitoring  

摘要： NMR spectroscopy is an indispensable method of analysis in chemistry, which until recently suffered from high demands for space, high costs for acquisition and maintenance, and operational complexity. This has changed with the introduction of compact NMR spectrometers suitable for small-molecule analysis on the chemical workbench. These spectrometers contain permanent magnets giving rise to proton NMR frequencies between 40 and 80MHz. The enabling technology is to make small permanent magnets with homogeneous fields. Tabletop instruments with inhomogeneous fields have been in use for over 40years for characterizing food and hydrogen-containing materials by relaxation and diffusion measurements. Related NMR instruments measure these parameters in the stray field outside the magnet. They are used to inspect the borehole walls of oil wells and to test objects nondestructively. The state-of-the-art of NMR spectroscopy, imaging and relaxometry with compact instruments is reviewed.