COC(=O)[C@H](COC(C)(C)C)NC(=O)O[C@@H]1Cc2cc(Br)ccc2O[C@H]1c1cccc(OC)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?