You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
(2R,3S,4S,4aS,10bS)-3,4,8,10-tetrahydroxy-2-(hydroxymethyl)-9-methoxy-7-[[(3S)-3-methylpiperidin-1-yl]methyl]-3,4,4a,10b-tetrahydro-2H-pyrano[3,2-c]isochromen-6-one The above is the IUPAC name of a molecule. Write its molecular formula.
user
C21H29NO9
assistant