pharmacological interest, as their core structure is a common
element in cancer chemotherapeutic agents such as doxorubicin,
mitomycin C, and mitoxantrone. It is presumably
capable of modulating oxidative biochemical processes.15
Accordingly, herbal quinones have been reported to possess
cytotoxic activity.5,16,17 A selection of the isolated compounds
was, therefore, assayed for activity against the MDA-MB-231
ER-negative human breast cancer cell line (Table 4). For
comparison, literature data obtained for known compounds on
ER-positive MCF-7 cells are also given. Of the tes