O=C(O[C@@H](/C=C/c1ccccc1)P1(=O)N(Cc2ccccc2)[C@@H]2CCCC[C@H]2N1Cc1ccccc1)c1ccccc1
Molecules with a polar surface area of greater than 140 angstroms squared (Å2) tend to be poor at permeating cell membranes. What's the psa of this molecule?