COc1ccc(O[C@H]2C=C[C@@H](c3ccccc3)O[C@@H]2COC(=O)CCC(C)=NO[C@@H]2O[C@H](COC(C)=O)[C@@H](OC(C)=O)[C@H](OC(C)=O)[C@H]2OC(C)=O)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.