Variation in the chemical profiles of three foxglove species in the central Balkans

• Published in: Frontiers in plant science Vol. 14; p. 1155297
• Main Authors: Gašić, Uroš, Banjanac, Tijana, Šiler, Branislav, Božunović, Jelena, Milutinović, Milica, Aničić, Neda, Dmitrović, Slavica, Skorić, Marijana, Nestorović Živković, Jasmina, Petrović, Luka, Todorović, Miloš, Živković, Suzana, Matekalo, Dragana, Filipović, Biljana, Lukić, Tamara, Mišić, Danijela
• Format: Journal Article
• Language: English
• Published: Switzerland Frontiers Media S.A 09-03-2023
• Subjects: cardiac glycosides; Digitalis grandiflora; flavonoids; phenylethanoids; Plant Science; steroids; UHPLC-LTQ OrbiTrap MS; phenylethanoids; Digitalis grandiflora; UHPLC-LTQ OrbiTrap MS; D. ferruginea; steroids; D. lanata; cardiac glycosides; flavonoids
• ISSN: 1664-462X; 1664-462X
• DOI: 10.3389/fpls.2023.1155297

The aim of this study was to determine intra- and interspecies variation in the qualitative and quantitative composition of methanol-soluble metabolites in the leaves of three
species (
,
, and
) from the central Balkans. Despite the steady use of foxglove constituents for human health as valuable medicinal products, populations of the genus
(
) have been poorly investigated to describe their genetic and phenetic variation. Following untargeted profiling using UHPLC-LTQ Orbitrap MS, by which we identified a total of 115 compounds, 16 compounds were quantified using the UHPLC(-)HESI-QqQ-MS/MS approach. In total, 55 steroid compounds, 15 phenylethanoid glycosides, 27 flavonoids, and 14 phenolic acid derivatives were identified across the samples with
and
showing a great similarity, while 15 compounds were characteristic only for
. The phytochemical composition of methanol extracts, considered here as complex phenotypes, are further examined along multiple levels of biological organization (intra- and interpopulation) and subsequently subjected to chemometric data analysis. The quantitative composition of the selected set of 16 chemomarkers belonging to the classes of cardenolides (3 compounds) and phenolics (13 compounds) pointed to considerable differences between the taxa studied.
and
were found to be richer in phenolics as compared to cardenolides, which otherwise predominate in
over other compounds. PCA revealed lanatoside C, deslanoside, hispidulin, and
-coumaric acid to be the main compounds contributing to the differences between
on one side and
and
on the other, while
-coumaric acid, hispidulin, and digoxin contribute to the diversification between
and
. However, quantitative variation in the metabolite content within species was faint with mild population diversification visible in
and particularly in
This pointed to the highly conserved content and ratio of targeted compounds within the analyzed species, which was not severely influenced by the geographic origin or environmental conditions. The presented metabolomics approach might have, along with morphometrics and molecular genetics studies, a high information value for further elucidation of the relationships among taxa within the genus
.