Design, synthesis, and antiproliferative activity of some novel aminosubstituted xanthenones, able to overcome multidrug resistance toward MES-SA/Dx5 cells.

A series of novel xanthenone aminoderivatives and their pyrazole-fused counterparts possessing structural analogy to the potent anticancer agent 9-methoxypyrazoloacridine (PZA) reported. These compounds exhibited an interesting cytotoxic activity against a panel of cell lines. Most noticeably, they retain activity against the multidrug resistant MES-SA/Dx5 subline, showing resistant factors close to 1.