Oleanane-Type Glycosides with α-Glucosidase Inhibitory Activity from Chenopodium serotinum L., an Everlasting Wild Vegetable

Chenopodium serotinum L. (Chenopodiaceae) is a folk medicine first recorded in Shi Jing (an ancient Chinese book of classic songs) with activities such as antipyretic and detoxification. To explorer the unknown species, the MeOH extract of its aerial part was isolated via various chromatographic techniques (e.g., such as Sephadex LH-20 column chromatography and HPLC) to give seven new oleanane-type triterpenoid glycosides, i.e., chenoponins A-G, isolated from the BuOH fraction. Six of them are rare 3-O-trioside, composed of one sophorosyl (i.e., Glc-(1→2)-Glc) and one arabinosyl moiety, which are otherwise known only from a single congeneric species, thereby providing more definitive evidence of their structural novelty within the genus. Their structures were elucidated on the basis of extensive spectroscopic analysis (1D/2D NMR, MS). Virtual screening of these compounds on α-glucosidase by molecular docking followed by an in vitro assay on the major ones indicated that chenoponin A (1) showed moderate activity against α-glucosidase with IC₅₀ values of 23.25 ± 1.00 μM.