CC(=O)O.COc1cc(C)cc2c(-c3c(O)cc(O)c4c3C[C@H](C)N[C@H]4C)cc(-c3cc(-c4c(O)cc(O)c5c4C[C@H](C)N[C@H]5C)c4cc(C)cc(OC)c4c3O)c(O)c12
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?