C[C@@H]1CCC2[C@](C)(CC[C@H](O)[C@@]2(C)CO)[C@@]12CC[C@@](CO)(CC(=O)[O-])O2.[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?