Showing structure for 15-hydroxy-18,19-dimethoxy-13,14-dimethyl-20-oxo-3,6,8-trioxapentacyclo[9.9.1.0¹,¹⁶.0⁴,²¹.0⁵,⁹]henicosa-4(21),5(9),10,16,18-pentaen-12-yl 2-methylbut-2-enoate