CCOC(=O)c1c(N2CCOCC2)[nH]c(=O)c(C(c2cccs2)c2c(O)c(C(=O)OCC)c(N3CCOCC3)[nH]c2=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?