NCCC(=O)N[C@H](Cc1cc(O)c(O)c(SCC(NC(=O)CC[C@H](N)C(=O)O)C(=O)NCC(=O)O)c1)C(=O)O
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?