Cc1nc(/N=N\c2ccc(S(=O)(=O)O)cc2S(=O)(=O)O)c(COP(=O)(O)O)c(C=O)c1O
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?