Cc1cc(O)c2cnncc3c(O)cc(C)c4c(=O)oc5c(CO)c(O)c(C(=O)O)c(cnncc6c(C(=O)O)c(O)c(CO)c7oc(=O)c1c2oc67)c5oc34
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?