抄録
i) Dianhydrorugulosin, C30H18O8, which was derived from rugulosin, C30H22O10, a pigment of P.rugulosum Thom, by a dehydrationreaction, was converted into bisnordianhydrorugulosin which was synthetically proved to be identical with 4, 5, 4', 5'-tetrahydroxybianthraquinone-(1, 1'). ii) Iridoskyrin, C30H18O10, a pigment of P.islandicum Sopp, yielded islandicin (1, 4, 5-trihydroxy-2-methylanthraquinone) by reductive cleavage with alkaline Na2S2O4. Dianhydrorugulosin gave chrysophanol by the same reaction. iii) Dianhydrorugulosin was derived from iridoskyrin by the action of HI and red phosphorus, then with CrO3, losing two hydroxyls. iv) By the above reactions, the structure of dianhydrorugulosin was established as being 4, 5, 4', 5'-tetrahydroxy-7, 7'-dimethylbianthraquinone-(1, 1'), while iridoskyrin was proved conversely to be 4, 5, 8, 4', 5', 8'-hexahydroxy-7, 7'-dimethylbianthraquinone-(1, 1'). v) A fundamental skeleton of rugulosin has been forwarded.
