You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
Convert the IUPAC name of a molecule (3R,6S,9S,12R,18S)-12-(1H-indol-3-ylmethyl)-6-[(4-methoxyphenyl)methyl]-3-methyl-9-(2-methylpropyl)-16-(3-methylpyridine-2-carbonyl)-18-propan-2-yl-1,4,7,10,13,16-hexazacyclooctadecane-2,5,8,11,14-pentone into molecular formula.
user
C44H56N8O7
assistant