COc1ccc(COC(=O)N/N=C2/C[C@@H](O)[C@@H](O)[C@H]3[C@@H]2CC[C@@H]2C(=O)N(C4CCCCC4)C(=O)[C@H]23)cc1
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.