O=S(=O)([O-])c1ccc2c(/N=N\c3cccc4ccccc34)c(O)c(S(=O)(=O)O)cc2c1.[Na+]
Molecules with a polar surface area of greater than 140 angstroms squared (Å2) tend to be poor at permeating cell membranes. What's the psa of this molecule?