Four New Steroidal Saponins from the Roots of Dracaena cambodiana with NO Production Inhibition Activity in LPS Activated RAW 264.7 Cells

Abstract

AbstractSeven steroidal saponins including three new 16,23‐cyclocholestanes (1‐3) and one new pregane (4) were isolated from the roots of Dracaena cambodiana Pierre ex Gagnep. Their chemical structures were elucidated to be (23R,25R)‐26‐O‐β‐D‐glucopyranosyl‐16,23‐cyclocholesta‐5,17(20)‐dien‐22‐one‐3β,16α,26‐triol‐3‐O‐α‐L‐rhamnopyranosyl‐(1→2)‐[α‐L‐rhamnopyranosyl‐(1→3)]‐β‐D‐glucopyranoside (1), (23R,25R)‐26‐O‐β‐D‐glucopyranosyl‐16,23‐cyclocholesta‐5,17,20(22)‐trien‐3β,22,26‐triol‐3‐O‐α‐L‐rhamnopyranosyl‐(1→3)‐β‐D‐glucopyranoside (2), (23R,25R)‐16,23‐cyclocholesta‐5,16,20(22)‐trien‐3β,22,26‐triol‐3‐O‐α‐L‐rhamnopyranosyl‐(1→3)‐β‐D‐glucopyranoside (3), 3β‐[(O‐α‐L‐rhamnopyranosyl‐(1→3)‐[α‐L‐rhamnopyranosyl‐(1→2)]‐β‐D‐gluco‐pyranosyl)oxy]‐pregna‐5,17(20)‐diene‐16‐one‐20‐carboxylic acid 4′′′′‐O‐β‐D‐glucopyranosylisopentyl ester (4), cambodianoside A (5), diosbulbiside C (6), and diosbulbiside D (7), by IR, HR‐ESI‐MS, 1D and 2D NMR spectra. Compounds 1 and 4–7 inhibited nitric oxide (NO) production in lipopolysaccharide activated RAW 264.7 cells with IC50 values ranging from 19.03±1.84 to 67.92±3.81 μM, whereas compounds 2 and 3 were inactive with IC50 values over 100 μM.