O=c1ccn([C@@H]2O[C@H](CNS(=O)(=O)C3CC3)[C@@H](O)[C@H]2O)c(=O)[nH]1
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?