Antileukæmic Activity of Polyporic Acid

IN the course of screening indigenous plant products for experimental anti-cancer activity, a preparation of the lichen Sticta coronata was found to prolong significantly the life-span of mice previously inoculated with an acute lymphocytic leukæmia. Polyporic acid (2,5-dihydroxy 3,6 diphenyl 1,4 benzoquinone) isolated from Sticta coronata was shown to possess antileukæmic activity and to account completely for that of the original crude extract. Synthetic polyporic acid shows similar antileukæmic activity to that of the naturally occurring compound, and no reference to antitumour action has been encountered by us.