CCCCCNC(=O)[C@H](Cc1ccc(N(C(=O)C(=O)O)c2ccccc2C(=O)O)c(/C=C/C(N)=O)c1)NC(=O)[C@H](Cc1ccccc1)NC(=O)CCC(=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?