O=C(OC1CO[C@H]2O[C@@H]1[C@H](OC(=O)c1ccccc1)[C@H]2OC(=O)c1ccccc1)c1ccccc1
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?