Structurally Diverse Secondary Metabolites from the Stem of Tinospora cordifolia and Their Anti-Inflammatory Potential on RAW264.7 Macrophages

Six new secondary metabolites were isolated from the stem extract of Tinospora cordifolia, including two polyoxygenated sterols, cordisterone A (1) and cordisterone B (3), two terpenes, cordipene A (2) and cordipene B (4), a C-glucoside, cordiside A (5), rare 2-(4-amino-2-hydroxybutyl) benzoic acid, cordizoic acid (6), and 18 (7-24) known compounds. Compounds 7 and 8 were isolated for the first time from this plant. Their structures, including absolute configurations, were determined by detailed examination of 1D/2D NMR, HRESIMS spectroscopic data, optical rotation, and electronic circular dichroism (ECD) calculations. Extracts, fractions, and pure compounds were evaluated for their nitric oxide inhibitory effects in lipopolysaccharide-activated RAW264.7 cells. Cordiside A (5) significantly inhibited nitric oxide (NO) production in murine macrophage cells with an IC₅₀ value of 3.79 ± 0.68 μM and exhibited low cytotoxicity (IC₅₀ > 50 μM), whereas 2 and 6 showed moderate activity. Cordiside A (5) also inhibited interleukin-6 (IL-6) and TNF-α significantly at the concentration of 12.5 μM with the IC₅₀ values of 5.12 ± 0.56 and 8.61 ± 0.69 μM, respectively. This study disclosed the discovery and structure characterization of six new compounds and the significant therapeutic potential of the new C-glycoside (5) in combating inflammation-related diseases.