ABSTRACT
The family Amaryllidaceae is also recognizable chemically for its isoquinoline alkaloid constituents. In terms of molecular size phenanthridones are small relative to other alkaloid based anticancer drugs such as camptothecin and vincristine and even smaller than other natural product anticancer agents such as podophyllotoxin and Taxol. Given that the 2-piperidone unit making up ring-B is tetra-substituted by way of two further cyclic systems, the resulting compactness makes for little chemical space to probe for structure–activity relationship purposes. Studies which explored the effects of the ring-A fragment on cytotoxic activity were understandably drawn to the C-7, C-8, and C-9 positions which hold in place the phenolic hydroxy and methylenedioxy groups. Given that a phenanthridone target could in future appear on the cancer market significant strides have been taken towards understanding the molecular basis to their cytotoxic effects. Tumor Necrosis Factor are a group of proinflammatory cytokines that have been implicated in tumor regression, septic shock, and cachexia.
