You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
For the molecule named (7S,9S)-7-[(2R,4S,5S,6S)-4-amino-5-hydroxy-6-methyloxan-2-yl]oxy-6,9,11-trihydroxy-4-methoxy-9-methyl-8,10-dihydro-7H-tetracene-5,12-dione by IUPAC nomenclature, provide its molecular formula.
user
C26H29NO9
assistant