QS-S2

O[C@H]([C@@H]([C@H]([C@@H](O1)C)O[C@H]2[C@@H]([C@H]([C@@H](CO2)O)O)O)O)[C@@H]1O[C@H]([C@H]([C@H]([C@H](O3)C)OC(C[C@@H](O)C[C@@H]([C@@H](C)CC)OC(C[C@@H](O)C[C@@H]([C@@H](C)CC)O[C@@H]4O[C@H]([C@@H]([C@H]4O)O)CO)=O)=O)O)[C@@H]3OC([C@]56[C@](CC(C)(CC6)C)([H])C7=CC[C@@]([C@@]8([C@@]([C@@](C)([C@H](CC8)O[C@H]9[C@@H]([C@H]([C@@H]([C@H](O9)C(O)=O)O)O[C@H]%10[C@@H]([C@H]([C@@H](CO%10)O)O)O)O[C@@H]%11O[C@@H]([C@@H]([C@@H]([C@H]%11O)O)O)CO)C=O)([H])CC%12)C)([H])[C@]%12(C)[C@@]7(C[C@H]5O)C)=O

[1]Bankefors J, et al. Structural classification of acyl-substituted Quillaja saponins by electrospray ionisation ion trap multiple-stage mass spectrometry in combination with multivariate analysis. Rapid Commun Mass Spectrom. 2008 Dec;22 (23) :3851-60.|[2]Deng K, et al. Synthesis of QS-21-xylose: establishment of the immunopotentiating activity of synthetic QS-21 adjuvant with a melanoma vaccine. Angew Chem Int Ed Engl. 2008;47 (34) :6395-8.