Progesterone In Plants

The letter to the editor by Craig McClure (C&EN, Aug. 23, page 4) referring to the article about plant progesterone (C&EN, Feb. 8, page 13) and our original article (J. Nat. Prod. 2010, 73, 338) contains several errors.

First, the original article did not overlook, but rather acknowledged, the work of John D. Carson et al. on Pinus taeda (Environ. Toxicol. Chem. 2008, 27, 1273). In the Supporting Information, the entire section S1 is devoted to previous work on the detection of progesterone in plants, accompanied by numerous citations. Regrettably, reference No. 7 was incorrect, which we can now trace back to a bibliographic database error that occurred during manuscript preparation.

Second, neither Carson et al. nor Ronald L. Jenkins et al. (Toxicol. Sci. 2003, 73, 53) isolated progesterone. Their identification of progesterone was ultimately LC-MS-MS based, but without isolation and ­NMR spectroscopic characterization.

Third, the original article did not claim to report “the first evidence” but rather what C&EN called “rigorous evidence” for progesterone in a higher plant. In contrast to McClure’s assertion, the introduction of the original article clearly links to pertinent reports on this topic and refers to S1 of the Supporting Information for further details. Moreover, the introduction discusses differences in analytical specificity and addresses the vital role of purified material for unequivocal compound identification.

Recently, Supporting Information has become an integral part of scientific publications and essential to research communication. Thus, I agree with McClure on one point: It is regrettable that published literature does not receive a more thorough reading, in its entirety, and including the Supporting Information.

Guido F. Pauli
Chicago