Novel anti-inflammatory phytoconstituents from Desmodium gangeticum

A new aliphatic enone, (17Z,20Z)-hexacosa-17,20-dien-9-one (3), and one new bisindole alkaloid, gangenoid (6), together with seven known compounds were isolated from the roots and aerial parts of Desmodium gangeticum (family: Leguminosae). All the compounds except 2 and 7 were isolated from this plant for the first time, which may be of chemotaxonomic importance. Structures of compounds 3 and 6 were determined on the basis of their detailed spectroscopic analyses (NMR, IR and mass). In addition, compounds 3 and 6 were investigated for their effects on lipopolysaccharide-stimulated macrophages for the production of pro-inflammatory cytokines such as tumour necrosis factor-α and interleukin-6.