Showing structure for 12,13-dimethoxy-3,5,10,17-tetraoxapentacyclo[9.6.2.0²,⁶.0⁸,¹⁸.0¹⁵,¹⁹]nonadeca-1(18),2(6),7,11,13,15(19)-hexaene-9,16-dione