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 IC₅₀ values of 160 and 180 μM, respectively. Moreover, compounds 2 and 3 showed strong inhibition against α-glucosidase and lipase, with the respective IC₅₀ values of 170 and 190 μM, and 190 and 200 μM.

Chemical synthesis of a trisaccharide related to the cytotoxic triterpenoid saponins isolated from the bark of Albizia procera has been accomplished through a concise stepwise glycosylation strategy starting from commercially available D-xylose, 2-acetamido-2-deoxy-D-glucose and L-arabinose. The target trisaccharide was designed with a 4-methoxyphenyl (MP) aglycone to extend the scope of conversion to suitable glycoconjugates via selective removal of 4-methoxyphenyl (MP) group. An unexpected phenomenon, i.e., the arabinosyl residue assumed the ¹C₄ conformation instead of the typical ⁴C₁ form, was observed. Deprotection could restore the normal conformation.

The four hederagenin glycosides 1–4 were efficiently synthesized through one-pot sequential glycosylations with glycose 1-(trichloroacetimidate)s as donors, resulting in a significantly simplified synthetic procedure without isolation of glycosylation intermediates. The activity of the synthetic hederagenin glycosides 1–4 against α-glucosidase type IV was evaluated; hederagenin glycoside 4 containing an α-L-rhamnopyranosyl unit showed the best activity with an IC₅₀ value of 47.9 μM.

The first total synthesis of benzophenone O-glycosides (iriflophenone 2-O-α-L-rhamnopyranoside: 1 and aquilarisinin: 2) isolated from the leaves of Aquilaria sinensis and related new derivatives (3–12) was accomplished through suitable protecting group manipulations and glycosylation starting from commercially available L-rhamnose, D-glucose, D-galactose, D-mannose, D-xylose, and 1,3,5-trihydroxybenzene. All synthesized benzophenone O-glycosides were evaluated for their inhibitory activities against α-glucosidase. Of these, benzophenone O-glycosides 4 and 10 exhibited the most potent inhibitory activity in vitro against α-glucosidase with IC₅₀ values of 168.7 ± 13.9 and 210.1 ± 23.9 µM, respectively, when compared with that of the positive control acarbose with an IC₅₀ value of 569.3 ± 49.7 µM.