NC(=O)[C@H](Cc1ccccc1)NC(=O)[C@H](Cc1c[nH]c2ccccc12)NC(=O)[C@@H]1CCCN1C(=O)[C@@H](N)Cc1ccc(O)cc1
Hydrogen bond acceptor is the chemical compound which contains the lone electron pairs that participate in the hydrogen bond formation. This compound should contain a more electronegative atom (more electronegative than hydrogen) with lone electron pairs. Then it can attract protons from a donor. Moreover, the electronegative atoms usually involved in hydrogen bonding are oxygen, nitrogen and fluorine. How many hydrogen bond acceptors does the molecule contain?