COc1cc2c(cc1OC)-c1c(oc3cc(OC4OC(CO)C(O)C(O)C4O)c(OC)cc3c1=O)C(O)O2
Molecules with a polar surface area of greater than 60 angstroms squared (Å2) is hard to pass brain blood barrier. What's the psa of this molecule?