Five New Oleanane Triterpene Saponins from <i>Camellia petelotii</i> and Their Alpha‐glucosidase Inhibitory Activity
Nguyễn Thị Cúc, Ngo Anh Bang, Bùi Hữu Tài, Nguyễn Xuân Nhiệm, Phạm Hải Yến, Dương Thị Hải Yến, Truong Thi Thu Hien, Le Thi Huyen, Phan Văn Kiệm
Abstract
Abstract Five new triterpenoid glycosides, named campetelosides A–E ( 1–5 ), together with three known compounds, chikusetsusaponin IVa ( 6 ), umbellatoside B ( 7 ), and silvioside E ( 8 ) were isolated from the leaves of Camellia petelotii (Merr.) Sealy. Their chemical structures were determined by interpretations of HR‐ESI‐MS and NMR spectra. In addition, compounds 1–8 were evaluated for their α ‐glucosidase inhibitory effects. Compounds 1–3 significantly showed α ‐glucosidase inhibitory activity with IC 50 values of 166.7±6.0, 45.9±2.6, and 395.3±10.5 μM, respectively, compared to that of the positive control, acarbose, with an IC 50 value of 200.4±10.5 μM.