COc1cc(-c2coc3cc(O[C@H]4OC(CO)C(O)C(O)C4O)c(OC)c(O)c3c2=O)cc(O)c1OC
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?