C[C@H](O)[C@@H](C(=O)N1CCN(C(=O)OC(C)(C)C)CC1)n1cc(CCCCNC(=O)OC(C)(C)C)nn1
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?