O=S1(=O)N[C@H]2CC[C@@H]3NS(=O)(=O)N[C@H]4CC[C@H](N1)N4S(=O)(=O)N23
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?