COc1cc([C@@H]2c3cc4c(cc3[C@@H](NCc3cccc(C#N)c3)C3COC(=O)[C@@H]32)OCO4)cc(OC)c1O
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?