Studies on Flavonoids in the Leaves of Coniferae and Allied Plants. II

Some yellow microcrystals of m.p. 263-264° (decomp.) were obtained from the dried leaves of Cycas revoluta THUNB. (Cycadales). This is a new flavone giving orange-red coloration to Mg+HCl, reddish purple to Zn+HCl, and greenish brown to ferric chloride. Its molecular formula agrees with C31H20O10, containing five hydroxyls and one methoxyl. From the agreement of its various derivatives, it was found to be monodemethylated compound of ginkgetin. This flavone has been named sotetsuflavone. This flavone, together with kayaflavone and sciadopitysin, were obtained from the leaves of Cryptomeria japonica D. DON var. araucarioides HORT (Taxodiaceae).