Oc1ccc2c3c1O[C@@H]1c4[nH]c5c(c4C[C@@]4(O)[C@@H](C2)N(CC2CC2)CC[C@]314)C[C@]1(O)[C@@H]2Cc3ccc(O)c4c3[C@@]1(CCN2CC1CC1)[C@H]5O4
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?