COC(=O)[C@H]1[C@@H](c2ccccc2)[C@@]2(c3ccccc3)Oc3ccccc3[C@@]1(O)[C@@H]2O
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?