O=C1c2ccccc2C(=O)N1CCCCc1cn(C[C@H]2CC[C@@H]([C@@H]3CC[C@H](Cn4cc(CCCCN5C(=O)c6ccccc6C5=O)nn4)O3)O2)nn1
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?