You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
Provide the molecular formula for the IUPAC named substance 3,6,7,17,21-pentahydroxy-18-nitroso-8,16-di(propan-2-yl)pentacyclo[11.8.0.02,11.04,9.015,20]henicosa-1(21),2,4(9),5,7,10,13,15(20),16,18-decaene-5,19-dicarbaldehyde .
user
C29H25NO8
assistant