CCOC(=O)CCN1C(=O)[C@@H]2[C@@H](CC[C@@H]3C(=O)C[C@@H](O)[C@@H](O)[C@H]32)C1=O
Hydrogen bond acceptor: The atom, ion, or molecule component of a hydrogen bond which does not supply the bridging (shared) hydrogen atom. How many hydrogen bond acceptors does the molecule have?