C[C@@H]1NC(=O)[C@H](CCC(N)=O)NC(=O)c2cc([N+](=O)[O-])cc(I)c2NCCC[C@@H](C(N)=O)NC1=O
PSA is a commonly used medicinal chemistry metric for the optimization of a drug's ability to permeate cells. Please predict psa of this molecule.