O=C1/C(=C/c2ccccc2S)N=C(c2ccccc2)N1c1ccc2c(c1)Sc1cc(N3C(=O)/C(=C/c4ccccc4S)N=C3c3ccccc3)ccc1N2
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?