Secondary metabolites from Triclisia gilletii (De Wild) Staner (Menispermaceae) with antimycobacterial activity against Mycobacterium tuberculosis
Triclisinone (2), a new ochnaflavone derivative, was isolated from the aerial parts of Triclisia gilletii, along with known drypemolundein B (1) and eight other known compounds. The chemical shifts of drypemolundein B (1) have been partially revised based on reinterpretation of NMR spectroscopic data. The eight other secondary metabolites are composed of: (+)-nonacosan-10-ol (3); stigmasterol (4), 3-O-β-D-glucopyranosylsitosterol (5), 3-O-β-D-glucopyranosylstigmasterol (6); oleanic acid (7); myricetin (8), quercetin (9) and 3-methoxyquercetin (10). Their structures were elucidated using IR, MS, NMR 1D and 2D, 1H and 13C and comparison with literature data. Furthermore, compounds 1, 2, 5, 6, 8, 9 and the crude extract were tested against Mycobacterium tuberculosis. Compounds 1, 2, 8 and 9 displayed moderate to very good activity against resistant strain (codified AC 45) of M. tuberculosis with minimum inhibitory concentrations MICs ranging from 3.90 to 62.5 μg/mL.
