O=C(Cn1c(=O)n(Cc2nc(-c3ccccc3)no2)c(=O)c2cc3c(cc21)OCO3)Nc1ccccc1
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?