C[C@H]1CC(=O)[C@@]2(O)C#C/C=C\C#C[C@@H]3Nc4c(cc(O)c5c4C(=O)c4ccccc4C5=O)[C@]24O[C@@]134
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?