O=c1ccn([C@@H]2O[C@@H](COP(=O)([O-])OP(=O)([O-])O)[C@H](O)[C@@H]2O)c(=O)[nH]1.[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?