Pinofuranoxins A and B, Bioactive Trisubstituted Furanones Produced by the Invasive Pathogen Diplodia sapinea.

Two new bioactive trisubstituted furanones, named pinofuranoxins A and B (1 and 2), were isolated from Diplodia sapinea, a worldwide conifer pathogen causing severe disease. Pinofuranoxins A and B were characterized essentially by NMR and HRESIMS spectra, and their relative and absolute configurations were assigned by NOESY experiments and computational analyses of electronic circular dichroism spectra. They induced necrotic lesions on Hedera helix L., Phaseolus vulgaris L., and Quercus ilex L. Compound 1 completely inhibited the growth of Athelia rolfsii and Phytophthora cambivora, while 2 showed antioomycetes activity against P. cambivora. In the Artemia salina assay both toxins showed activity inducing larval mortality.

Natural and Synthetic Furanones with Anticancer Activity.

This paper describes the enantioselective synthesis of analogues of sapinofuranones A and B, namely 5-substitutes dihydro- and 5H-furan-ones, and their in vitro growth inhibitory activity against six cancer cell lines in comparison with fungal furanones such as diplofuranone A, diplobifuranylones A and B, as well as (S,S)-enantiomer of sapinofuranone B. The compounds under study displayed weak if any in vitro growth inhibitory activity against the analysed cancer cell lines. -However, it seems that among dihydro- and 5H-furan-ones bearing a 1-hydroxypentyl side chain, the stereochemistry of the furanone ring and that of hydroxylated methine could modify the in vitro growth activity of these compounds. The natural furanones that showed a different unsaturated chain at C-4 or rearranged into a dihydrofuran ring appeared to be inactive in terms of growth inhibitory activity, e.g. displaying growth inhibitory concentration at 50% (GIs) > 100 ptM in all six cancer cell lines analysed.