O=C(O)Cc1ccc2c(c1)N(S(=O)(=O)c1cccc(C(F)(F)F)c1)CC(C(=O)O)O2
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?