CC(C(N)C(=O)NC(C(=O)O)C1OC(n2ccc(=O)[nH]c2=O)C(O)C1O)C(O)c1ccc(O)cn1
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?