Phenanthroindolizidines and phenanthroquinolizidines are structure-related alkaloids that are well known for their profound cytotoxicity toward a variety of cancer cells and thus have been explored to develop into anti-cancer agents. Tylophorine and cryptoleurine are representative of these two classes of alkaloids respectively. While tylophorine was conceivable to account for the anti-inflammation related effects for Tylophora indica and has been reported to exert significant anti-inflammatory effects in vitro and in vivo, not much known for cryptoleurine and its analogues for anti-inflammation related effects. Although over 70 of phenanthroindolizidine, phenanthroquinolizidine alkaloids, and their analogues have been purified or synthesized, systemic analyses for the structure-activity relationships are needed for more clear elucidation between or among the phenanthroindolizidines and phenanthroquinolizidines. Thus, We synthesized 16 compounds of phenanthroindolizidines (8 compounds, 2 sets) and their counterparts of phenanthroquinolizidines(8 compounds, 2 sets). We analyzed the relationships between the structures and activities of anti-cancer cell growth and anti-inflammation in in vitro systems and also probed the differential activity between and among the phenanthroindolizidines and phenanthroquinolizidines.
