C[C@@]1(O)CC(=O)c2c(cc3ccc(-c4c5c(c(O)c6c(O)cccc46)C(=O)C[C@](C)(O)C5)c(O)c3c2O)C1
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?