C=CCN([C@@H](CC(C)C)C(=O)OC)S(=O)(=O)N(CC=C)[C@@H](CC(C)C)C(=O)OC
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?