Secondary metabolites from Gentiana cruciata L. and their anti-inflammatory and analgesic activities

A previously unreported secoiridoid glycoside, cruciatoside (1) was isolated from the aerial parts of Gentiana cruciata L. along with ten known compounds eustomoside (2), eustomorusside (3), gentiopicroside (4), 6'-O-beta-D-glucopyranosyl gentiopicroside (5), loganic acid (6), isoorientin (7), isovitexin (8), isovitexin 2''-(E)-ferulate (9), mangiferin (10), and 2-methyl-inositol (11). The chemical structures of the isolates were elucidated based on extensive 1 D and 2 D NMR experiments as well as HRMS analysis. All isolates were evaluated for their in vitro anti-inflammatory and analgesic activities. Compounds 9, 4, and 7 (200 mu M) showed moderate anti-inflammatory activity by inhibiting nitrite production from LPS-induced RAW 264.7 macrophage cells, with the inhibition rates of 39.5%, 25.8% and 22.9% respectively without exhibiting substantial cytotoxicity. Besides, 1, 2, 4, and 7 exerted the highest decrease in IL-6 levels. Moreover, compound 4 showed in vitro analgesic activity by decreasing the PGE(2) level comparable to the reference drugs.

Automated summary

In this study, a previously unreported secoiridoid glycoside, cruciatoside, was isolated from Gentiana cruciata L., along with ten known compounds. Compounds 9, 4, and 7 showed moderate anti-inflammatory activity, while compounds 1, 2, 4, and 7 exhibited strong reduction in IL-6 levels. In addition, compound 4 showed in vitro analgesic activity.