Crodonsides A–D, four new guaiane-type sesquiterpenoid glycosides from Croton dongnaiensis and their xanthine oxidase inhibitory activities

Abstract

Four previously undescribed guaiane-type sesquiterpenoid glycosides, crodonsides A–D (1–4), together with nine known compounds (5–13), were isolated from the branches and leaves of Croton dongnaiensis (Euphorbiaceae). Their structures were elucidated by extensive analysis of HRESIMS, 1D and 2D NMR spectroscopic data, and the absolute configurations of compounds 1–4 were assigned by comparison of their experimental and TD-DFT calculated ECD spectra. The xanthine oxidase inhibitory activities of compounds 1–13 were evaluated. Compounds 1–6 and 10–13 exhibited moderate inhibitory activities, with IC50 values ranging from 16.08 ± 1.39 to 41.48 ± 1.85 µM, whereas compounds 7–9 showed weak activity (IC50 > 50 µM). These results expand the chemical diversity known from C. dongnaiensis and provide preliminary evidence for the xanthine oxidase inhibitory potential of its isolated constituents.