One-Step Semisynthesis Method of Spirocurcasone and Pyracurcasone from Curcusones A and B

High contents of curcusones A and B and trace amounts of spiro­curcasone exist in the roots of Jatropha curcas. Here, a one-step semi­synthesis method of spiro­curca­sone and pyra­curca­sone was built, not only resulted an increased yield of spiro­curca­sone but also produced pyra­curca­sone, which exhibited greater cytotoxicity compared to curcusones A and B. The plausible mechanism of the formation of pyra­curca­sone was proposed, and the proposed biogenetic origin for spiro­curcasone by Taglialatela-Scafati was confirmed.