CC(=O)Oc1cc(-c2coc3cc(OC(C)=O)c(OC(C)=O)c(OC(C)=O)c3c2=O)cc(OC(C)=O)c1OC(C)=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.