Pyrrolizidine alkaloids, glycosylated flavonols and phenolic acid derivatives from the aerial parts of Pardoglossum cheirifolium (L.) Barbier & Mathez.

In the present study, we aimed to report the identified chemical composition of methanol and n-butanol extracts obtained from the aerial parts of the Algerian Pardoglossum cheirifolium (L.) Barbier & Mathez. Heliosupine N-oxide (1) was isolated from the n-butanol extract and structurally characterised by extensive NMR and ESI-MS/MS data. LC-DAD-ESI/MS analysis on methanol extract aimed at determining pyrrolizidine alkaloids of which the Pardoglossum genus is a rich source, led to the proposed identification of lycopsamine N-oxide (2), echinatine N-oxide (3), dihydrolycopsamine (4), dihydroechinatine (5), 7-acetyl dihydrolycopsamine (6), 7-acetyllycopsamine N-oxide (7), 3'-acetylviridiflorine (8), vulgarine (10), and heliosupine (16). The glycosylated flavonols quercetin 3-O-rhamnopyranoside-(1→2)-glucopyranosyl-(1→6)-rhamnopyranoside (9), kaempferol 3-O-L-rhamnopyranosyl-(1→2)-rhamnopyranosyl-(1→6)-glucopyranoside (11), rutin (12), kaempferol 3-O-rutinoside (13), in addition to 3,4,5-trihydroxycinnamic acid glucopyranoside (14) and 3,5-dihydroxycinnamic acid-O-diglucopyranoside (15), were also identified. For the first time, we report the known metabolites 2 - 11 and 13 - 15 in the studied plant, both reported as Pardoglossum cheirifolium and Cynoglossum cheirifolium.