COc1cc(C(=O)C2CC3(CCC2(O)c2cc(OC)c(OC)c(OC)c2)CC(=O)Nc2ccccc2C3=O)cc(OC)c1OC
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.