C[C@H](O)C#Cc1ccc2c(c1)O[C@@H](CN(C)Cc1ccc(-c3ccccc3)cc1)[C@H](C)CN([C@@H](C)CO)S2(=O)=O
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?