O=C(O)c1cc(NC(=O)c2cccc(C(=O)Nc3cc(C(=O)O)cc(C(=O)O)c3)c2)cc(C(=O)O)c1
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?