EARLY in 1955 a screening programme was initiated for examining the indigenous New Zealand flora for anti-tumour agents. The first reproducible and significant results were obtained with a crude extract from the lichen Sticta coronata Mull Arg., whose biological activity, as indicated in a preliminary communication, l is due to the presence of polyporic acid (I; R= H, R'= OH). The occurrence of this acid in Sticta species had been ...
![3',6'-dichloro-4-methoxy-[1,1':4',1''-terphenyl]-2',5'-dione结构式](https://image.chemsrc.com/caspic/132/6361-65-5.png)
