CCOc1ccc(CCN2C(=S)N([C@@H](CC(C)C)CN3CCCC3CN3C(=S)NC[C@@H]3Cc3ccc(O)cc3)C[C@@H]2CC(C)C)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?