Showing structure for 6,7,17,21-tetrahydroxy-16-methoxy-11,21-dimethyl-10,20-dioxapentacyclo[10.7.2.0²,¹¹.0³,⁸.0¹³,¹⁹]henicosa-3(8),4,6,13(19),14,16-hexaen-18-one