COc1ccc2c3c(c(=O)oc2c1)[C@H]1O[C@](CCCCN2C(=O)c4ccccc4C2=O)(Cc2c1ccc1ccccc21)O3
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.