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Optimization Of Electrode Alignment For Electrochemical Detection In Capillary Electrophoresis Using A Scanning Electrochemical Microscope, David Roach, Stephanie Hooper, Mark Anderson

Mark R. Anderson

Electrochemical detection in capillary electrophoresis requires decoupling the voltage applied to the working electrode from the separation voltage applied across the capillary. End-capillary electrochemical detection achieves this by placing the electrode just outside the ground end of the separation capillary. Obtaining adequate signal-to-noise in this arrangement requires using small inner diameter capillaries. Decreasing the inner diameter of the separation capillary, however, increases the difficulty of aligning the microelectrode with the open end of the capillary. Using scanning electrochemical microscopy (SECM), the position of the capillary opening is determined while electroactive material is continuously emerging from the end of the capillary. …

Unraveling The Mechanism Of A Potent Transcriptional Activator, Brian Brennan, Zhen Lu, Steven Rowe, Sarah Davis, Renee Metzler, Johnathan Nau, Chinmay Majmudar, Anna Mapp, Aseem Ansari

Brian B. Brennan

Despite their enormous potential as novel research tools and therapeutic agents, artificial transcription factors (ATFs) that up-regulate transcription robustly in vivo remain elusive. In investigating an ATF that does function exceptionally well in vivo, we uncovered an unexpected relationship between transcription function and a binding interaction between the activation domain and an adjacent region of the DNA binding domain. Disruption of this interaction leads to complete loss of function in vivo, even though the activation domain is still able to bind to its target in the transcriptional machinery. We propose that this interaction parallels those between natural activation domains and …

Stereochemical Promiscuity In Artificial Transcriptional Activators, Brian Brennan, Sara Buhrlage, Aaron Minter, Anna Mapp

Brian B. Brennan

Small molecule replacements of transcriptional activation domains are highly desirable targets due to their utility as mechanistic tools and their long-term therapeutic potential for a variety of human diseases. Here, we examine the ability of amphipathic isoxazolidines differing only in the placement of constituent side chains to function as transcriptional activation domains. The results reveal that precise positioning of functional groups within a conformationally constrained small molecule scaffold is not required for transcription function; rather, the balance of polarity and hydrophobicity within the scaffold is the more important determinant of transcription function. This suggests that a number of different organic …

A Solvent-Free Baeyer–Villiger Lactonization For The Undergraduate Organic Laboratory: Synthesis Of Γ-T-Butyl-Ε-Caprolactone, John Esteb, James Hohman, Diana Schlamadinger, Anne Wilson

John Esteb

We present an experiment involving the Baeyer–Villiger oxidation reactionfor a first-year organic chemistry class. The Baeyer–Villiger reactionprovides an efficient method to convert ketones to esters or lactones. Most organictextbooks cover the Baeyer–Villiger reaction but owing to a lack of suitableexperiments, students seldom get to explore the reaction in the undergraduateteaching laboratory. In this experiment, m-chloroperoxybenzoic acid(m-CPBA) and4-tert-butylcyclohexanone are mixed together for 30 minutes under solvent-freeconditions to produce γ-t-butyl-ε-caprolactone in 95%yield. The solvent-free nature of this procedure greatly limits the quantityof waste generated by students and keeps costs low by removing the need for solvent.

Note:Link is to the article …