C[C@@H](CO)N1C[C@@H](C)[C@@H](CN(C)Cc2ccc(C(=O)O)cc2)Oc2cc(/C=C/c3ccccc3)ccc2S1(=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?