New phloroglucinol derivatives from Indonesian Baeckea frutescens

Chemical investigation of the leaves of Baeckea frutescens (Myrtacea) led to the isolation and characterization of five new phloroglucinol derivatives, baeckenones G−K (1–5), together with two known compounds, ursolic acid (6) and humulene (7). The chemical structures were determined by extensive 1D- and 2D-NMR, and MS spectroscopic analyses. Baeckenones J (4) and K (5) exhibited antiproliferative activities against human lung A549 and pancreatic PSN-1 cancer cell lines, with IC50 values ranging from 11.8 to 19.2 μM.