CC(=O)n1cc([C@@H]2C=C(C(=O)N3CCN(Cc4ccccc4)CC3)O[C@H](OCc3ccc(CO)cc3)C2)c2ccccc21
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?