Showing structure for methyl 10,15,16-trihydroxy-9,13-dimethyl-3-[(3-methylbut-2-enoyl)oxy]-4,11-dioxo-5,18-dioxapentacyclo[12.5.0.0¹,⁶.0²,¹⁷.0⁸,¹³]nonadec-9-ene-17-carboxylate