CC(C)[C@]1(O)[C@@H](OC(=O)c2ccc[nH]2)[C@]2(O)[C@@]3(C)C[C@@]4(O)O[C@@]5([C@H](O)[C@@H](C)CC[C@]35O)[C@]2(O)[C@]41C
A higher negative pKa value denotes a less powerful acid. What is this molecule's negative pKa value?