NC(=O)C(CC(=O)O)NC(=O)[C@@H]1CCOc2c(I)cc([N+](=O)[O-])cc2C(=O)N[C@@H](CO)C(=O)N[C@@H](Cc2ccc(O)cc2)C(=O)N1
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?