Rosanortriterpene C, a 3,24-Dinor-2,4-seco-ursane Triterpene from the Fruits of Rosa laevigata var. leiocapus.

One new 3,24-dinor-2,4-seco-ursane triterpene, rosanortriterpene C (1), together with four known compounds including 24-norursane-type nortriterpenes (2-3), 24-noroleanane-type nortriterpene (4), ursane-type triterpene (5), was isolated from the fruits of Rosa laevigata var. leiocapus. The new structure was elucidated through comprehensive spectroscopic analysis, including one dimensional (1D) and 2D NMR data, as well as electrospray ionization high resolution (HR-ESI) MS and IR spectrometry. Compounds 1-5 showed moderate anti-inflammatory activities against the production of nitric oxide (NO) in RAW264.7 cells stimulated by lipopolysaccharide (LPS) with IC₅₀ values of 10.35 ± 0.92, 14.28 ± 1.20, 5.04 ± 1.43, 29.29 ± 3.64, and 14.37 ± 0.59 µM, respectively.