Secondary metabolites from Triclisia gilletii (De Wild) Staner (Menispermaceae) with antimycobacterial activity against Mycobacterium tuberculosis

Abstract

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.

Keywords:

• Triclisia gelletii
• Menispermaceae
• ochnaflavone derivative
• NMR chemical shift analysis
• antimycobacterial activity

Acknowledgements

We thank Mr V. Nana for the collection and identification of the plant material. We thank Mr Felix Fehr, Department of Chemistry, University of Fribourg, and Koert’s team of Philipps-Universität Marburg for spectral analysis.