COc1cc(C(=O)C/C(CCCC(=O)Nc2ccccc2[N+](=O)[O-])=N/NC(=O)c2cc3ccccc3cc2O)ccc1O
Hydrogen bond acceptor: The atom, ion, or molecule component of a hydrogen bond which does not supply the bridging (shared) hydrogen atom. How many hydrogen bond acceptors does the molecule have?