An amendment to this paper has been published and can be accessed via a link at the top of the paper.In the version of this article previously published, several components of Fig. 1 were missing. In panels c and d, radicals were omitted from the compound structures; in panel e, the arrow going downward from arachidonate was partially removed. Additionally, the structure of ML094 in Fig. 4 was incorrect. The 1,3-cyclohexadiene ring on the south end of the molecule should be a naphthyl ring. The errors have been corrected in the HTML and PDF versions of the paper.