Antiproliferative Trihydroxyalkylcyclohexenones from Pleiogynium timoriense

Investigation of a DCM extract of the bark of Pleiogynium timoriense from the former Merck collection of natural product extracts for antiproliferative activity indicated that it was active with an IC₅₀ value of 1.3 g/mL against the A2780 ovarian cancer cell line. Bioassay-directed fractionation of this extract yielded the three new bioactive trihydroxyalkylcyclohexenones 1-3. Their structures were determined by a combination of spectroscopic and chemical methods. Compounds 1-3 exhibited submicromolar antiproliferative activity against the A2780 human ovarian cancer cell line, with IC₅₀ values of 0.8, 0.7, and 0.8 M, respectively.