Cytotoxic phloroglucinols from the leaves of Myrtus communis.

Bioactivity-guided fractionation of a dichloromethane extract of the leaves of Myrtus communis led to the isolation of phloroglucinol derivatives. The structures of the new myrtucommulones J, K, and L (1-3) and the previously known myrtucommulone A (4) were elucidated on the basis of extensive 1D and 2D NMR experiments as well as high-resolutionmass spectrometry. Myrtucommulone J was obtained as a tautomeric pair (1/1a). The compounds were tested in vitro for their cytotoxic and antibacterial activities.