Rakanmakilactones A–F, new cytotoxic sulfur-containing norditerpene dilactones from leaves of Podocarpus macrophyllus var. Maki

Six new S-containing norditerpene dilactones, rakanmakilactones A–F (), were isolated from the leaves of Podocarpus macrophyllus D. Don var. maki Endl., along with four known norditerpene dilactones (). Their structures, stereochemistry and absolute configurations were determined by spectroscopic studies (HRMS, IR, 1H, 13C and 2D NMR), and single-crystal X-ray analyses. Rakanmakilactones were found to have a cytotoxic effect against P388 murine leukemia cells.