Leptocarposide: a new triterpenoid glycoside from Ludwigia leptocarpa (Onagraceae)

Abstract

A new triterpenoid bidesmoside (leptocarposide) possessing an acyl group in their glycosidic moiety (1), together with the known luteolin-8-C-glucoside (2) and 1-O-β-D-glucopyranosyl-(2S,3R,8E)-2-[(2'R)-2-hydroxypalmitoylamino]-8-octadecen-1,3-diol (3) was isolated from the n-butanol-soluble fraction of whole plant of Ludwigia leptocarpa (Nutt) Hara (Onagraceae). Structure of compound 1 has been assigned on the basis of spectroscopic data ((1)H and (13)C NMR, (1)H-(1)H COSY, HSQC, HMBC, and ROESY), mass spectrometry, and by comparison with the literature. This compound was further screened for its potential antioxidant properties by using the radical scavenging assay model 2,2-diphenyl-1-picrylhydrazyl and reveals non-potent antioxidant activities, while compound 2 shows SC50 of 0,038 mM.

Saponins and Flavonoids from Ludwigia leptocarpa (Nutt) Hara (Onagraceae): Isolation, Characterization, Antibacterial and Antioxidant Activities

“…A leaf infusion has laxative, vermifugal and antidysenteric properties. Previous studies of this genus have revealed the presence of flavonoids, cerebrosides and triterpenoids [3,4]. A study recently reported that alcoholic extracts of L. octovalvis, L. abyssinica, L. decurrens and L. Leptocarpa, potentially have antioxidant, antibacterial and antifungal activities [2,5].…”

Structural Elucidation of Saponins

“…Concerning the glycosylation, the bonds with sugars can be recognized by the glycosylation shift: the formation of the ether linkage causes a downfield shift of the carbon values, while the esterification brings an upfield shift of the carboxylic carbon [42,47,61]. NMR is useful also in this framework.…”

“…Concerning the sugar chains, once the exact sequence of 1 H and 13 C of each sugar has been defined, the interglycosidic linkages have to be determined and the chain structure can be achieved once again by NMR, based on glycosylation shift and on HMBC correlations usually observed among the anomeric proton and the carbon of the second sugar involved in the linkage [39,49,54,56,61].…”

“…Their identity can be obtained from NMR data, while their position can be inferred by the shift induced in proton and carbon resonances, but especially by HMBC correlations observed among the carboxylic carbon and the sugar proton [45,48,50,57,61]. Their identity can be obtained from NMR data, while their position can be inferred by the shift induced in proton and carbon resonances, but especially by HMBC correlations observed among the carboxylic carbon and the sugar proton [45,48,50,57,61].…”

Complex secondary metabolites from <i>Ludwigia leptocarpa</i> with potent antibacterial and antioxidant activities

“…A leaf infusion has laxative, vermifugal, and antidysenteric properties. Previous studies of this genus have revealed the presence of flavonoids (19,20), cerebrosides, and triterpenoids (20,21). A study recently reported that alcoholic extracts of the leaves of L. octovalvis, L. abyssinica, and L. decurrens potentially have antioxidant, antibacterial, and antifungal activities (22,23).…”