A New Flavonol Glucoside from Turpinia montana Kurz and Its Synergistic NO Inhibitory Activity with a Triterpene Glucoside.

INTRODUCTION: The purpose of this study was to analyze the anti-inflammatory potential of the phytochemical constituents of Turpinia montana Kurz, with a focus on nitric oxide (NO) inhibition and potential synergistic effects among isolated substances. METHODS: The chemicals were isolated from methanolic extracts of T. montana leaves and twigs using combined chromatographic methods. The ability of each compound to decrease NO generation in RAW 264.7 macrophages activated with LPS was examined. Combination tests were used to further evaluate synergistic interactions, and the Chou-Talalay method was used for quantitative analysis. RESULTS: One new flavonol glucoside, 7-O-(1,1-dimethyl-3-oxobutan-1-y1)kaempferol 3-O-β-Dglucopyranoside (1) and seven known compounds, kaempferol 3-O-β-D-glucopyranoside (2), 2α,3β,19α-trihydroxy-5α,9α-urs-12-en-28-oic acid-28-O-β-D-glucopyranosyl ester (3), pedunculoside (4), rotungenoside (5), quadranoside III (6), urolic acid (7), and icariside E3 (8) were isolated. Moderate NO inhibitory activity was demonstrated by compounds 1, 3, and 4. Increased effects were found in combination experiments, especially for the combination Comp.1/Comp. 4, which showed consistent synergy with DRI values of roughly 4-9. DISCUSSION: The anti-inflammatory properties of T. montana may result from the consequence of synergistic interactions between its ingredients. It may reflect the value of combination-based phytochemical approaches. CONCLUSION: The study confirms the anti-inflammatory properties of T. montana leaves and twigs. The overall bioactivity may be partially attributable to synergistic interactions.