While the naturally occurring reducing agents glutathione (GSH) and ascorbate (H2A) alone are ineffective at reducing iron(III) sequestered by the siderophore ferrioxamine B, the addition of an iron(II) chelator, sulfonated bathophenanthroline (BPDS), facilitates reduction by either reducing agent. A mechanism is described in which a ternary complex is formed between ferrioxamine B and BPDS in a rapidly established pre-equilibrium step, which is followed by rate limiting reduction of the ternary complex by glutathione or ascorbate. Spectral, thermodynamic, and kinetic evidence are given for ternary complex formation. Ascorbate was found to be slightly more efficient at reducing the ternary complex than glutathione (k4=2.1 x 10(-3) M(-1) s(-1) and k4=6.3 x 10(-4) M(-1) s(-1), respectively) at pH 7. Reduction is followed by a rapid ligand exchange step where iron is released from ferrioxamine B to form tris-(BPDS)iron(II). The implications of these results for siderophore mediated iron transport and release are discussed.

A group of five graduate students and a faculty mentor used the cultural popularity of forensics to develop a first-year undergraduate seminar. This course fulfilled two main objectives: First, the graduate student instructors developed professionally through a two-year process of creating, instructing, and revising a course. Second, a variety of pedagogical techniques including lectures, in-class demonstrations, laboratories, student presentations, and mock criminal investigations were used to teach an introductory-level forensics seminar course with substantial chemistry content. Herein, we share our experiences in developing an effective course structure in which students were introduced to science through forensics, with an emphasis on the development of essential skills, including critical thinking and public speaking. An assessment of the project's impact on graduate students, undergraduate students, and the department is also provided.

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