COc1ccc(C(=O)OCC2OC(n3cnc4c(=S)nc[nH]c43)C(OC(=O)c3ccc(OC)cc3)C2OC(=O)c2ccc(OC)cc2)cc1
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?