C[C@@H]1NC(=O)C/C=C\[C@@H](C)[C@@H]2C=C[C@H](O)[C@@H](COC(=O)[C@H](C)NC(=O)C/C=C\[C@@H](C)[C@@H]3C=C[C@H](O)[C@@H](COC1=O)O3)O2
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.