COC(=O)C1=C(O)C(C(=O)OC)[C@]2(O)[C@H](C(=O)OC)[C@H]1C[C@@H](c1ccc(OC)c(OC)c1)[C@H]2C(=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?