Leaves of Cannabis sativa and their trichomes studied by DESI and MALDI mass spectrometry imaging for their contents of cannabinoids and flavonoids. Issue 3 (18th January 2023)

• Record Type: Journal Article
• Authors: Lorensen, Marcus Daniel Brandbjerg Bohn; Hayat, Sidra Yasmine; Wellner, Niels; Bjarnholt, Nanna; Janfelt, Christian
• Is Part Of: Phytochemical analysis. Volume 34:Issue 3(2023)
• Page Start: 269
• Page End: 279
• Publication Date: 2023-01-18
• Subjects: cannabinoids -- Cannabis sativa -- flavonoids -- mass spectrometry imaging -- trichomes; Plants -- Analysis -- Periodicals; Plants -- chemistry -- Periodicals; 572.2
• DOI: 10.1002/pca.3202
• Languages: English
• ISSNs: 0958-0344

Abstract

Abstract: Introduction: In recent years, industrial production of Cannabis sativa has increased due to increased demand of medicinal products based on the plant. In these medicinal products, it is mainly the contents of cannabinoids like THCA and CBDA which are of interest, but also the flavonoids of C. sativa have pharmaceutical interest. Objectives: The primary aim is to study the distribution of the different cannabinoids in leaves of C. sativa and specifically to which extent they are located on the trichomes found on the surface of C. sativa leaves. Desorption electrospray ionization (DESI) and matrix assisted laser desorption ionization (MALDI) mass spectrometry imaging (MSI) provide non‐targeted imaging of numerous compounds in the same experiment. Therefore, the distribution of flavonoids is also mapped in the same experiments. Material and methods: Fan leaves from C. sativa were imaged in the lateral dimension using direct DESI‐MSI as well as indirect DESI‐MSI via a porous PTFE surface using pixel sizes of 150–200 μm. For cross sections of sugar leaves, MALDI‐MSI was performed at 20 μm pixel size. Results: From indirect DESI‐MSI experiments, a connection was made between the cannabinoid CBGA and capitate‐stalked trichomes. Other cannabinoids like THCA/CBDA (isomers, which are not resolved in an MSI experiment) were also detected in the capitate‐stalked trichomes, but in addition to this also in the small glandular trichomes. MALDI‐MSI experiments on cross sections of sugar leaves confirmed that the cannabinoids were not an integral part of the leaf tissue itself, but originated from the trichomes on the surface of the leaf. Conclusion: The study provides visual evidence that the cannabinoids are produced and accumulated in the trichomes of C. sativa leaves. Abstract : Fan leaves from C.sativa were imaged in the lateral dimension using DESI‐MSI and cross sections of sugar leaves were imaged by MALDI‐MSI. The cannabinoid CBGA was detected in capitate‐stalked trichomes, and other cannabinoids like THCA/CBDA were detected in the capitate‐stalked trichomes and the small glandular trichomes. MALDI‐MSI experiments on cross sections of sugar leaves confirmed that the cannabinoids were not an integral part of the leaf tissue itself, but originated from the trichomes on the surface of the leaf.