Synthesis and structure-activity studies of antofine analogues as potential anticancer agents.

Due to the profound cytotoxicities and interesting biochemical aspects, phenanthroindolizidine alkaloids have received an attention as potential therapeutic leads. To define the features of the molecule that are essential for cytotoxicity, we have synthesized and evaluated a series of phenanthroindolizidine alkaloid, antofine, analogues with different substituents on the phenanthrene ring. The systematic structure activity relationship studies elucidate the essential functional group requirement of phenanthrene ring, providing the basis for further development of phenanthroindolizidine alkaloids.