Chemotaxonomic Markers for the Leaf Buds of Common Finnish Trees and Shrubs: A Rapid UHPLC MS Fingerprinting Tool for Species Identification

Abstract

In this study, a chemotaxonomic tool was created on the basis of ultra-high-performance liquid chromatography–mass spectrometry (UHPLC–MS) for the identification of 13 common Finnish deciduous trees and shrubs from their leaf bud metabolites. The bud extracts were screened with UHPLC–ESI–QqQ–MS and UHPLC–ESI–Q–Orbitrap–MS to discover suitable markers for each species. Two approaches were tested in the marker selection: (1) unique species-specific markers to obtain selective fingerprints per species and (2) major markers to maximise the sensitivity of the fingerprints. The markers were used to create two selected ion-recording-based fingerprinting tools with UHPLC–ESI–QqQ–MS. The methods were evaluated for their selectivity, repeatability, and robustness in plant species identification by analysing leaf buds from several replicates of each species. The created chemotaxonomic tools were shown to provide unique chromatographic profiles for the studied species in less than 6 min. A variety of plant metabolites, such as flavonoids, triterpenoids, and hydroxycinnamic acid derivatives, were found to serve as good chemotaxonomic markers for the studied species. In 10 out of 13 cases, species-specific markers were superior in creating selective and repeatable fingerprints.

Mass Spectrometric Fingerprint Mapping Reveals Species-Specific Differences in Plant Polyphenols and Related Bioactivities

“…The good overall activity of pyrogallol over catechol functions was further highlighted by the relatively high levels of myricetin glycosides in all these three species. Moreover, the main polyphenol in S. phylicifolia is the flavanol dihydromyricetin [1,18,28,41,42] that has the same oxidatively active pyrogallol function that is seen in all myricetin-type flavonols. Obviously, its dihydrated structure (MW 320 g/mol) will not be detected by the myricetin-specific MS/MS detection tools (myricetin's MW is 318 g/mol), but its presence can be easily witnessed by its UV spectrum typical to flavanols and the main m/z values of 319 ([M-H] − ion) and 639 ([2M-H] − ion) from the full scan MS data that is simultaneously acquired with the group-specific MS/MS chromatograms.…”

“…Plants produce a huge number of specialized metabolites for their own protection; several thousands of compounds can be detected from a single species using modern highresolution mass spectrometric (HR-MS) tools when the compounds are first at least partially separated by ultrahigh performance liquid chromatography (UHPLC) or other efficient separation techniques [1]. These approaches are very useful in revealing especially the metabolomic pool of small-molecular-weight compounds in plants, but larger compounds might not be detected at all depending on the specific parameters optimized for sample preparation, mass spectrometric ionization and ion selection and detection.…”

“…These approaches are very useful in revealing especially the metabolomic pool of small-molecular-weight compounds in plants, but larger compounds might not be detected at all depending on the specific parameters optimized for sample preparation, mass spectrometric ionization and ion selection and detection. Such a pool of thousands of smaller metabolites detected per plant species forms a great chemotaxonomic resource, since a carefully selected set of these individual compounds can function as chemotaxonomic markers effectively discriminating many of the species [1][2][3][4][5]. What makes this approach a very efficient one is the fact that the identity of the detected ions and the corresponding compounds do not have to be known.…”

Chemodiversity of Arctic Plant Dryas oxyodonta: LC-MS Profile and Antioxidant Activity

“…The similarity in chemical composition and the identification of patterns in the metabolomes of plant species from the same family offer insights into their chemodiversity. Chemical compounds aid in species identification and quality control of herbal medicinal products that are increasing in popularity [ 16 ]. To perform chemodiversity studies, advanced analytical tools like high-performance liquid chromatography with photodiode-array detection and electrospray ionization triple-quadrupole mass spectrometric detection (HPLC–PDA–ESI–tQ–MS) are indispensable, serving as instrumental tools for fingerprinting plant extracts.…”