CO[C@H]1[C@@H](OC(N)=O)[C@H](O)[C@@H](Oc2ccc3c(O)c(NC(=O)c4ccc([O-])c(CC=C(C)C)c4)c(=O)oc3c2C)OC1(C)C.[Na+]
The electronegative atoms usually involved in hydrogen bonding are oxygen, nitrogen and fluorine. How many hydrogen bond acceptors does the molecule contain?