COC(=O)C(Cc1ccc([N+](=O)[O-])cc1)NC(=O)C(CC(=O)OC(C)(C)C)NC(=O)OC(C)(C)C
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?