An Eye-Opening Experience

2014 essay contest winner Kevin Romero\u27s An Eye-Opening Experienc

Thinking about the Future

Brian Gilbert, associate professor of chemistry, has been influential in the education of Kevin Romero, class of 2015

Theoretical Study of the Pseudomonic and Monic Acids

The drug Mupirocin has shown positive effects against both Gram-negative and Gram-positive bacteria with varying levels of success. It has been shown to be effective against Methicillin-Resistant Staphylococcus Aureas (MRSA) as a topical treatment in high concentrations. Mupirocin is comprised of pseudomonic acids. The monic acids are structurally similar to the pseudomonic acids and thus function as a good model to better understand the chemical characteristics of the drug. This work presents results of DFT (B3LYP) calculations with an accurate basis set on monic acid A and related species with focus on internal rotation barriers, optimal geometries, IR and Raman spectra, and electrostatic potentials to identify the differences between the monic and pseudomonic acids with an eye towards potential antibacterial treatments

Memantine for prevention of migraine: a retrospective study of 60 cases.

The objective was to retrospectively characterise the efficacy of memantine as preventive therapy in a series of patients with frequent migraine. Patients in a university headache clinic completed a survey regarding their experience with memantine, and medical records were reviewed. All patients who received memantine as preventive therapy for migraine over a 15-month period were mailed surveys and consent forms for record review. Patients were treated with memantine beginning at a dose of 5 mg/day, increasing if needed by 5 mg/week up to 10 mg twice a day. The majority of patients (36 out of 54) treated with memantine for at least 2 months reported a significant reduction in estimated headache frequency, and improved function. Side effects were uncommon and generally mild. This limited retrospective case review suggests that memantine may be an effective preventive therapy for patients with frequent migraine. A prospective trial is warranted

Theoretical Studies of Several Small-Ring Precursors to (+)-JQ1

We present the results of DFT(B3LYP) calculations on several precursors to (+)-JQ1 using an accurate basis set, including a report of conformational analysis, thermochemistry, optimized geometries and electrostatic potentials, and calculated IR and Raman spectra. Species include (I)1H-1,4-diazepin-2(3H)-imine, (II) 9H-[1,2,4]triazolo[4,3-a][1,4]diazepine, (III) 6H-thieno[3,2-f][1,2,4]triazolo[4,3a][1,4]diazepine, and (IV) 4-(4-chlorophenyl)-6H-thieno[3,2f][1,2,4]triazolo[4,3-a][1,4]diazepine. Studies are also reported on monobrominated (II)-(IV) substituted at the chiral center of the seven member ring, including a comparison of the energetics of equatorial versus axial bromination of the parent precursor. Implications with regard to the larger structure of (+)-JQ1 are discussed

Lessons Learned From Using An Ill-Conceived Nonmonetary, Prepaid Incentive In A Self-Administered Survey Of College Students

An experiment was conducted to determine how effective a prepaid, nonmonetary incentive would be at inducing college students to participate in a self-administered survey. The experiment was conducted on two college campuses in Los Angeles County.  As students exited their campus library, an interviewer approached them for an interview.  Half of those approached were offered a prepaid, nonmonetary incentive; the other half were not. Contrary to expectations, the prepaid, nonmonetary incentive dampened the response rate to the survey. Explanations are offered as to why the incentive was counterproductive

Statistical and kinetic study for leaching of covellite in a chloride media

Covellite is a relatively rare copper sulfide with slow dissolution kinetics. The present investigation used the surface optimization methodology to evaluate the effect of three independent variables (time, chloride concentration and sulfuric acid concentration) on the rate of extracting Cu from covellite. The effects of chloride concentration and temperature over time were also studied. An ANOVA indicated that the linear variables of time and chloride concentration have the greatest influence, this being highly representative (R2 = 0.9945). The highest copper extraction rate (71.23%) at room temperature, was obtained with a high chloride concentration (100 g/L), a low concentration of sulfuric acid (0.5 M), and a leaching period of 600 h. The dissolution is described by the model of the unreacted core, the rate of leaching of the covellite is controlled by the chemical surface reaction at temperatures between 50 and 90°C, with concentrations of 0.5 M of H2SO4, 100 g/L of chloride, and a leaching period of up to 6 hours, where an activation energy of 72.36 kJ/mol was obtaine.The authors are grateful for the contribution of the Scientific Equipment Unit-MAINI of the Universidad Católica del Norte for aiding in generating data by automated electronic microscopy QEMSCAN® and for facilitating the chemical analysis of the solutions. We are also grateful to Marina Vargas Aleuy and Carolina Ossandón Cortés of the Universidad Católica del Norte for supporting the experimental tests

Persistent Radicals in Natural Product Synthesis: A Biomimetic Approach to Resveratrol Oligomers

Since their discovery 120 years ago, carbon-centered free radicals have captivated the attention of organic chemists worldwide. As the thermodynamic and kinetic properties of radical reactions have been studied, it has been recognized that open-shell intermediates offer complementary and orthogonal modes of reactivity when compared to traditional polar mechanisms. Persistent radicals, which by definition have higher kinetic barriers for reactivity, serve to increase the selectivity with which radical reactions occur through the persistent radical effect – a phenomenon that has recently begun to be leveraged for synthesis. The work described herein seeks to advance the field of radical chemistry in the context of employing persistent radicals for synthesis through synergistic combination of physical organic chemistry and chemical synthesis. In particular, these efforts target chemical synthesis of oligomers from the resveratrol class of natural products – an extensive and structurally diverse set of polyphenols to which a broad range of biological activities has been ascribed – with the goal of better understanding the mechanism(s) by which these compounds are biologically active. Chapter 1 summarizes the state of the field of radical chemistry in the context of natural product synthesis, concluding with a discussion of how persistent radicals have begun to be employed. The inspiration for the synthetic approach described in the subsequent chapters derives from the final example in which, during the course of a natural product total synthesis campaign, a key equilibrium between persistent phenoxyl radicals and their dimeric adducts was discovered and leveraged to access C8–C8′ resveratrol dimers and tetramers. Chapter 2 details how a mild, sustainable, and scalable approach for the generation of these persistent radicals was developed by relying upon electrochemical oxidation. This new method enabled the synthesis of a set of natural product analogs for initial structure-activity relationship (SAR) analysis of the compounds as radical trapping antioxidants (RTAs). Surprisingly, it was determined during the course of this study that the persistent radicals are more potent RTAs than any of the polyphenols evaluated, calling into question the exact cellular role these compounds fulfill in nature. Finally, Chapter 3 describes how thermodynamic study of the equilibrium between the persistent phenoxyl radicals and the corresponding C8–C8′ dimers resulted in the discovery of a C8–C8′ to C3–C8′ homolytic bond migration. This reaction was subsequently leveraged as the key step for the synthesis of the resveratrol tetramers vitisin A and vitisin D – two members of a subset of resveratrol oligomers to which perhaps the most interesting biological activity has been attributed. This chapter concludes with a discussion of where this project is headed in terms of the use of these persistent radicals for intermolecular C8–C10′ bond-forming reactions to access resveratrol trimers. In total, the strategy developed herein for resveratrol oligomer synthesis mimics the proposed manner in which Nature constructs these complex molecules, offering a direct route for the evaluation of their pharmacological potential.PHDChemistryUniversity of Michigan, Horace H. Rackham School of Graduate Studieshttps://deepblue.lib.umich.edu/bitstream/2027.42/155104/1/kevjrom_1.pd