Bioactivity-guided isolation of anti-inflammatory effect from roots of Streptocaulon juventas collected in An Giang (Streptocaulon juventas (Lour.) Merr., Apocynaceae)

Abstract

   Chemical composition analysis and anti-inflammatory activity evaluation of Streptocaulon juventas (Lour.) Merr. (Apocynaceae) root harvested in An Giang. From 10 kg of dried roots, the extraction fractions of n-hexane (111 g), chloroform (117 g), ethyl acetate (17 g), butanol (12 g), and water (460 g) were obtained by liquid-liquid partitioning. The chloroform fraction exhibited strong anti-inflammatory activity with an IC₅₀ value of (32.83 ± 0.26) µg/mL in the nitric oxide (NO) production inhibition assay using RAW 264.7 cells. Three pure compounds were isolated and structurally elucidated by NMR spectroscopy and ESI-HRMS: lupeol acetate (SJ1, 50.2 mg), acovenosigenin A (SJ2, 15.3 mg), and periplocymarin (SJ3, 14.6 mg). However, these compounds showed insignificant NO inhibitory activity (< 50 %) at concentrations of (30 and 100) µM. The results clarify the chemical constituents and anti-inflammatory potential of Streptocaulon juventas root, providing a scientific basis for its application in traditional medicine.