CC(=O)OC1CC[C@]2(C#N)[C@H]3CC[C@]4(C)[C@H](C5C=CC(=O)O5)CCC4(O)C3CCC2(O)C1
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?