O=C(OC1Cc2c(O)cc(O)cc2OC1c1cc(O)c(O)c(O)c1-c1c(C2Oc3cc(O)cc(O)c3CC2O)cc(O)c(O)c1O)c1cc(O)c(O)c(O)c1
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?