O=C(Nc1ccccc1)OC1OC(COC(=O)c2ccccc2)C(OC(=O)c2ccccc2)C1OS(=O)(=O)c1ccc([N+](=O)[O-])cc1
Molecules possible for drug usually have no more than 5 Hydrogen bond acceptor. How many hydrogen bond acceptors does the molecule have?