Chemical and biological investigation of some secondary metabolites in Atriplex halimus growing in Egypt

Abstract

The n-BuOH-soluble fraction of the MeOH-CH2Cl2 (1:1) extract of the aerial parts of Egyptian Atriplex halimus L. yielded two new flavonol glycosides, designated as atriplexoside A (1) [3′-O- methylquercetin-4′-O-β-apiofuranoside-3-O-(6″-O-α- rhamnopyranosyl-β-glucopyranoside)] and atriplexoside B (2) [3′-O-methylquercetin-4′-O-(5″″-O-β-xylopyranosyl- β-apiofuranoside)-3-O-(6″-O-α-rhamnopyranosyl-β- glucopyranoside)], together with six known compounds: two phenolic glucosides (3, 4), one ecdysteroid (5), one megastigmane (6) and two methoxylated flavonoid glycosides (7, 8). The structures of the compounds were elucidated by detailed spectroscopic analysis, including HR-ESI-MS and 2D-NMR spectroscopic data. DPPH radical scavenging, antileishmanial and anti-multidrug resistance activities were investigated using the n-BuOH-soluble fraction as well as the isolated compounds. Compound 8 (5-O-methylquercetin-3-O-(6″-O-α- rhamnopyranosyl-β-glucopyranoside) presented marked DPPH radical scavenging, weak antileishmanial and antimultidrug resistance activity while the other tested compounds showed weaker activities.