CC1=C(C(=O)OCc2ccccc2)N2C(=O)[C@@H](N(Cc3ccccc3)Cc3ccccc3)[C@H]2SC1
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?