Skip to main content
. Author manuscript; available in PMC: 2017 Mar 1.
Published in final edited form as: Chem Sci. 2016 Jan 15;7(3):2371–2380. doi: 10.1039/c5sc02978c

Fig. 1.

Fig. 1

(a) Structure of the saponin natural product immunoadjuvant QS21 (≈2:1 mixture of 1a/1b). (b) Structures of a simplified semisynthetic lead compound 2 and corresponding glycosidic linkage variants 3–9 designed to probe the effects of linker length, stereochemistry, and conformational flexibility upon adjuvant activity. Four-number SQS (synthetic QS) codes designate structural variants in each of the four corresponding structural domains of QS21, left to right, with 0 assigned to the natural product structure.