CCCC(=O)Nc1nc2c(ncn2[C@@H]2O[C@H]3COP(=O)(O)O[C@@H]3[C@@H]2OC(=O)CCC)c(=O)[nH]1
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?