COC(=O)[C@@H](c1ccccc1)N(C)S(=O)(=O)c1cccc(S(=O)(=O)N(C)[C@@H](C(=O)OC)c2ccccc2)c1
Hydrogen bond acceptor is the chemical compound which contains the lone electron pairs that participate in the hydrogen bond formation. How many hydrogen bond acceptors does the molecule contain?