Nc1ccccc1/N=N/c1c(S(=O)(=O)[O-])cc2cc(S(=O)(=O)[O-])cc(O)c2c1O.[Na+].[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?