O=C(NC12C3C4C5C1C2C(Br)(C43)C51OCCO1)NC12C3C4C5C1C2C(Br)(C43)C51OCCO1
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?