O=c1oc2ccc([N+](=O)[O-])cc2c(Nc2ccc3c(c2)S(=O)(=O)c2ccccc2O3)c1[N+](=O)[O-]
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?