Concise Synthesis and Antidiabetic Effect of Three Natural Triterpenoid Saponins Isolated from Fadogia ancylantha (Makoni tea)

The first concise synthesis of the bidesmosidic oleanolic acid saponins 1 – 3 isolated from Fadogia ancylantha (Makoni tea) have been accomplished through a ‘one‐pot sequential glycosylation’ strategy with two glycosyl 1‐(trichloroacetimidate)s as glycosyl donors. The synthesized natural products 1 – 3 were then evaluated for their inhibitory activities against α ‐glucosidase, α ‐amylase, and lipase. Among the assayed compounds 1 – 3 , compound 1 showed strong α ‐glucosidase and α ‐amylase inhibition, with IC 50 values of 160 and 180 μ M , respectively. Moreover, compounds 2 and 3 showed strong inhibition against α ‐glucosidase and lipase, with the respective IC 50 values of 170 and 190 μ M , and 190 and 200 μ M .