C=C(C=O)C[C@@H]1C[C@H](O)C2OC3C[C@]4(C)OC5/C=C\CC6OC7C(CC=CCC6OC5CCCC4OC3CC2O1)OC1CC2OC3CC(=O)OC3C[C@@H](C)C[C@@]2(C)OC1C[C@@H]7C
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?