CC(=O)OCC1OC(n2c(Br)nc3c(=O)[nH]c(N)nc32)C(OC(C)=O)C1OC(C)=O
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?