Tomoeones A-H, cytotoxic phloroglucinol derivatives from Hypericum ascyron

Eight phloroglucinols, tomoeones A-H were isolated from the leaves of Hypericum ascyron. Their structures were established based on spectroscopic analyses. Cytotoxicities of tomoeones (A-H) against human tumor cell lines were evaluated. Tomoeone F (6) demonstrated significant cytotoxicity against KB cells with an IC50 value of 6.2 μg/mL.