CC(=O)O[C@H]1C[C@@]2(C)[C@@H](CC[C@H]3[C@@]4(C)C=CC(=O)[C@@H](C)[C@@H]4[C@H](OC(C)=O)C(=O)[C@@]32C)/C1=C1\CC[C@H](C(C)(C)O)OC1=O nordammarane triterpenoid