Cn1c2ccccc2c2c3c(c4c5ccccc5n(C5OC(CO)C(O)C(O)C5O)c4c21)C(=O)OC3=O
A rotatable bond is defined as any single non-ring bond, attached to a non-terminal, non-hydrogen atom. Amide C-N bonds are not counted because of their high barrier to rotation.  How many rotatable bonds does the molecule have?