Glycosides of polygalacic acid from the stem barks of Piper guineense Schum and Thonn

2021

Article référencé dans le Web of Science WOS:000678535300007

Kamto E. L., Note O. P., Kinyok M., Wilhelm A., Mbing J. N., Antheaume C., Atchad A. D., Pegnyemb D. E., Ndinteh D. T., Haddad Mohamed, Bonnet S. L.

Carbohydrate Research, 2021, 507, 108374 [7 p.] ISSN 0008-6215

In a continuation of our study on constituents of P. guineense now focusing on the search for saponins, phytochemical investigation of the n-BuOH fraction of P. guineense stem bark led to the isolation of three previously undescribed triterpenoid saponins, named guineenosides AC (13). Their structures were established on the basis of extensive analysis of 1D and 2D NMR (1H, 13C NMR, DEPT, COSY, TOCSY, NOESY, HSQC, HSQC-TOCSY and HMBC) and HRESIMS experiments, and by chemical evidence as 3-O-{alpha-L-rhamnopyranosyl-(1 -> 3)-beta-Dxylopyranosyl-(1 -> 2)-alpha-L-arabinopyranosyl-(1 -> 4)-alpha-L-rhamnopyranosyl-(1 -> 3)-[alpha-L-arabinofuranosyl-(1 -> 4)]-alpha-L-rhamnopyranosyl-(1 -> 3)-beta-D-fucopyranosyl} polygalacic acid 28-O-alpha-L-rhamnopyranosyl-(1 -> 4)-alpha-Lrhamnopyranosyl-(1 -> 3)-beta-D-xylopyranosyl ester (1), 3-O-{alpha-L-rhamnopyranosyl-(1 -> 3)-beta-D-xylopyranosyl-(1 -> 2)-alpha-L-arabinopyranosyl-(1 -> 4)-alpha-L-rhamnopyranosyl-(1 -> 3)-[alpha-L-arabinofuranosyl-(1 -> 4)]-alpha-L-rhamnopyranosyl-(1 -> 3)-beta-D-fucopyranosyl} polygalacic acid 28-O-beta-D-glucopyranosyl-(1 -> 3)-alpha-L-rhamnopyranosyl(1 -> 4)-alpha-L-rhamnopyranosyl-(1 -> 3)-beta-D-xylopyranosyl ester (2), and 3-O-{alpha-L-rhamnopyranosyl-(1 -> 2)-beta-Dxylopyranosyl-(1 -> 3)-beta-D-fucopyranosyl} polygalacic acid 28-O-[alpha-L-rhamnopyranosyl-(1 -> 4)-alpha-L-rhamnopyranosyl-(1 -> 3)-beta-D-xylopyranosyl ester (3). This is the first report of triterpenoid saponins from P. guineense.

Sciences fondamentales / Techniques d'analyse et de recherche [020] ; Sciences du monde végétal [076]

Fonds IRD [F B010082586]

fdi:010082586