New cytotoxic natural products from the marine sponge-derived fungus Pestalotiopsis sp. by epigenetic modification

摘要

Four new polyketide derivatives, pestalotiopols A–D ( 1–4 ), together with seven known compounds ( 5–11 ), were isolated from a chemical-epigenetic culture of Pestalotiopsis sp. The structures and absolute configurations of the new compounds ( 1–4 ) were determined by spectroscopic analyses, Mo _(2) -induced CD, and electronic circular dichroism (ECD) calculations. All the isolated compounds ( 1–11 ) were tested for their cytotoxic activities. Among these compounds, compounds 1 , 2 , 6 and 7 exhibited cytotoxicity against four human cancer cell lines with IC _(50) values of 16.5–56.5 μM. The structure–activity relationships of compounds ( 1–11 ) were examined. The results indicated that both the diol system of the side chain and the aldehyde group might contribute to the cytotoxic activity. The possible biosynthetic pathways for compounds ( 1–4 ) were also postulated.