Researcher Responds To Retraction Of Papers

A former Columbia University doctoral student, Bengü Sezen, says in an e-mail exchange with C&EN that she protests the retraction of two papers and parts of a third that she coauthored with Dalibor Sames, a chemistry professor at Columbia. The papers were published in the Journal of the American Chemical Society (2005, 126, 13244; 127, 3648 and 5284).??

In her e-mail to C&EN, Sezen writes: "The reactions described in these publications were performed independently by my colleagues in my absence before the submission of papers; thus these retractions came as a surprise to me. I strongly protest that the retractions were made without my knowledge."

Sames retracted the JACS papers in written notices published in the March 8 issue of JACS (2006, 128, 3102). He says other scientists could not reproduce the results reported by Sezen.

Sezen communicated with C&EN via a Columbia e-mail address. However, she is currently listed as a Ph.D. student in the lab of molecular biology professor Elmar Schiebel at the University of Heidelberg, in Germany. She had been accepted as a postdoc in the laboratory of Chaitan Khosla, professor of chemistry, chemical engineering, and biochemistry at Stanford University. Khosla says the appointment has been "indefinitely delayed" due to the Columbia investigation.

Sezen continues: "During the past week, I have tried to contact professor Sames about [the retraction of papers] without any success. I have preserved copies of experimental data, which support the original claims of these publications, but was not given a chance to present these data. I am also prepared to perform the reactions under the supervision of professor Sames if I am given a chance."

"We were always suspicious about [Sezen], but we did not bring the matter to professor Sames because there was no smoking gun," says former Sames group member Brenton DeBoef, now a chemistry professor at the University of Rhode Island, Kingston. He says outside research groups reported that they could not reproduce her results. In the lab, "while she was there, we were able to reproduce stuff. Academic fraud is a very serious offense. I am sure the Sames group would not pursue this unless they had good evidence."

DeBoef says he smelled trouble from the time he began working in the lab as a postdoc in June 2003. At that time, he says, he set up a project with a graduate student and eight months later they had results to publish. In that time period, he says, Sezen published two papers. "It seemed too good to be true."

The retracted work concerns the selective activation of C???H bonds on a molecule, a technique commonly used to functionalize hydrocarbons. In the case of the Sames group, the technique is applied to the creation of complex organic molecules, for example, total synthesis of a natural product. The work could reduce the number of synthetic steps needed to make a given molecule, an important goal for chemists who work in the field of drug discovery.

Sames has declined to speak further with C&EN while an investigation of Sezen and her work is under way at Columbia. Sezen was awarded a Ph.D. degree in chemistry by Columbia in 2005.

DeBoef says of Sezen: "I enjoyed working with her. She's very smart. She's diligent, and she worked long hours." But DeBoef says he is troubled by reports that her work cannot be reproduced. "These reactions don't work. I am pretty sure of that. Somebody else should be able to do this. It needs to be able to be reproduced by someone else."

In a later e-mail to C&EN, Sezen lists three examples in which she says members of the Sames group did reproduce the results of her work before it was published. In all three instances, Sezen says, she was absent from the lab.

Columbia University has forbidden Sames or members of his research group to speak to the media about Sezen or the university's investigation. The scientists Sezen identified as being able to reproduce her work are both members of the Sames group. They declined to verify her assertions or otherwise speak with C&EN.