Isolation and structure elucidation of a new potent anti-neoplastic diterpene from Dendrostellera lessertii

Two diterpene esters were isolated from Dendrostellera lessertii. These compounds were identified as compound I (12-O-benzoyl-3,5-hydroxy-6,7-epoxy-resiniferonol-9,13,14-orthobenzoate) and compound 11 (12-O-benzoyl-5-hydroxy-6,7-epoxy-resiniferonol-9,13,14-orthodecanoate). Cytotoxicity evaluation of these two compounds, using seven different cancerous cell lines, indicated that compound I with IC50 of 5-25 nmol, is 2.5 times more active than compound II. Using flow cytometry technique, it was found that treatment of the most responsive cells (K562) with compound I inhibited the progression of cells through G1 phase by almost 20% compared to the untreated cells.