CC1OC(Oc2ccc3ccc(=O)oc3c2-c2c(O)ccc3cc(Oc4ccc5ccc(=O)oc5c4)c(=O)oc23)C(O)C(O)C1O
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?