CC(C)(C)OC[C@H](NC(=O)OC(C)(C)C)c1nnc([C@H](CC(=O)OC(C)(C)C)NC(=O)C2CCN(C(=O)OC(C)(C)C)CC2)o1
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?