Plant Seed Species Identification from Chemical Fingerprints: A High-Throughput Application of Direct Analysis in Real Time Mass Spectrometry

Abstract

Plant species identification based on the morphological features of plant parts is a well-established science in botany. However, species identification from seeds has largely been unexplored, despite the fact that the seeds contain all of the genetic information that distinguishes one plant from another. Using seeds of genus Datura plants, we show here that the mass spectrum-derived chemical fingerprints for seeds of the same species are similar. On the other hand, seeds from different species within the same genus display distinct chemical signatures, even though they may contain similar characteristic biomarkers. The intraspecies chemical signature similarities on the one hand, and interspecies fingerprint differences on the other, can be processed by multivariate statistical analysis methods to enable rapid species-level identification and differentiation. The chemical fingerprints can be acquired rapidly and in a high-throughput manner by direct analysis in real time mass spectrometry (DART-MS) analysis of the seeds in their native form, without use of a solvent extract. Importantly, knowledge of the identity of the detected molecules is not required for species level identification. However, confirmation of the presence within the seeds of various characteristic tropane and other alkaloids, including atropine, scopolamine, scopoline, tropine, tropinone, and tyramine, was accomplished by comparison of the in-source collision-induced dissociation (CID) fragmentation patterns of authentic standards, to the fragmentation patterns observed in the seeds when analyzed under similar in-source CID conditions. The advantages, applications, and implications of the chemometric processing of DART-MS derived seed chemical signatures for species level identification and differentiation are discussed.

Application of ambient ionization high resolution mass spectrometry to determination of the botanical provenance of the constituents of psychoactive drug mixtures

“…[43,44] It has been demonstrated previously that forensically relevant plant material, including seeds, leaves, and wood, can be analyzed for detection of biomarkers, and that the chemical fingerprint produced can provide species-level discrimination and identification of mind-altering plant substances using statistical analysis tools. [9,10,45] However, this method has not been successfully applied to compounded mixtures comprised of complex matrices. We surmised that DART-HRMS might be an ideal method for the characterization and identification of Ayahuasca brew components.…”

“…The use of these botanical psychotropic products have been implicated in multiple poisonings and fatalities. [1][2][3][4][5][6][7][8] Although inroads are being made into the identification of abused substances derived from single plant species, [9,10] a major challenge that confronts efforts to curtail the use of plant psychoactives is the absence of suitable analytical methods to accurately identify compounded plant-based products. Prescription and illicit drugs, as well as synthetic cathinones and cannabinoid products, are generally comprised of pure or semi-purified components that A c c e p t e d M a n u s c r i p t 7 can be identified by conventional analytical techniques.…”

Rapid High-throughput Species Identification of Botanical Material Using Direct Analysis in Real Time High Resolution Mass Spectrometry

“…[9][10][11][12] Compound identities were confirmed through elemental composition determination, isotope matching, and comparisons to reports in literature. [23][24] Heat map renderings of the direct analysis in real time-high resolution mass spectrometry spectra of Kratom and Datura are illustrated in Figure 4. The data presented were used in principal component analysis (PCA) to differentiate between the two classes of plant-based drugs of abuse ( Figure 5).…”

“…Multivariate statistical analysis has been applied to a wide variety of direct analysis in real time-high resolution mass spectrometry data, including that derived from wood, puparial casings, seeds, leaf material, and biodiesel fuelstocks, showcasing the versatility and reproducibility of the method. [22][23][24][25][26] The high-throughput capabilities of direct analysis in real time-high resolution mass spectrometry enable the acquisition of large amounts of mass spectral data in a short time period, and the large number of replicates needed for statistical analysis are easily acquired using this method. The direct analysis in real time-high resolution mass spectrometry mass spectral dataset of Datura and Kratom was comprised of over 100 individual spectra that were collected with less than an hour of total time investment.…”

Rapid Discrimination of Closely Related Seed Herbs (Cumin, Caraway, and Fennel) by Direct Analysis in Real Time Mass Spectrometry (DART-MS)

“…DART-MS in combination with a multivariate analysis such as principal component analysis (PCA) is, therefore, an ideal tool for the rapid chemical profiling of plant species and for the identification of herbal products. [22][23][24][25][26][27][28][29][30] To the best of our knowledge, there have been no studies about the discrimination of these traditional herbs cumin, caraway and fennel by DART-MS technique.…”