In a groundbreaking study emerging from Stellenbosch University, South African analytical chemists have unveiled the first evidence of a rare class of phenolic compounds known as flavoalkaloids within Cannabis leaves. This discovery not only deepens our understanding of Cannabis biochemistry but also expands the potential therapeutic scope of this historically medicinal plant beyond its well-known cannabinoids. Using state-of-the-art techniques in two-dimensional liquid chromatography combined with high-resolution mass spectrometry, the research team accomplished an unprecedented level of chemical profiling on Cannabis phenolics, opening new avenues for biomedical exploration.
Phenolic compounds have long commanded attention in pharmaceutical research due to their potent biological activities, including antioxidant, anti-inflammatory, and anticancer effects. Flavonoids — a well-researched subclass of phenolics — are ubiquitous in plants and have formed the foundation for numerous health-related applications. However, flavoalkaloids, a hybrid class possessing both flavonoid and alkaloid structural characteristics, remain extraordinarily rare, their presence historically reported in only a handful of plant species worldwide. The revelation that flavoalkaloids exist within Cannabis leaf tissue adds a compelling new layer to the chemical complexity of this plant and hints at yet-undiscovered pharmacological potentials.
The study meticulously analyzed three commercially cultivated Cannabis strains indigenous to South African agriculture. Using comprehensive two-dimensional liquid chromatography (2D-LC), the researchers separated and identified a total of 79 distinct phenolic compounds. Remarkably, 25 of these compounds had never before been reported in Cannabis, while 16 were tentatively attributed to the novel flavoalkaloid class. The concentration and distribution of these flavoalkaloids were found to be highly strain-specific and predominantly located in the leaves of a single Cannabis strain, underscoring an unexpected biochemical diversity even among closely related cultivars.
The use of two-dimensional liquid chromatography proved vital in resolving the complex mixture of phenolics that characterizes Cannabis. Typical one-dimensional chromatographic techniques often fall short in separating compounds with closely related structures, particularly in samples as chemically intricate as Cannabis, which contains over 750 known metabolites. The advanced methodology enhanced resolution by coupling two independent separation mechanisms sequentially, effectively distributing the phenolic compounds across a 2D plane according to their distinct affinities and chemical properties. This technological refinement was critical in isolating flavoalkaloids from the more abundant flavonoids, which would otherwise obscure their detection.
The analytical effort was spearheaded by Dr. Magriet Muller of Stellenbosch University’s Central Analytical Facility LC-MS laboratory. Dr. Muller’s doctoral research focused on refining these chromatographic and mass spectrometric techniques, which had previously been applied successfully to complex botanical matrices such as rooibos tea, grapes, and wine. Her initiative to redirect these methods towards Cannabis phenolics arose from a recognition of both the plant’s chemical complexity and the relative paucity of detailed phenolic characterization in Cannabis research up to this point. The successful application of 2D-LC-HRMS has now established a powerful analytical platform for future investigations into Cannabis and other botanicals.
Study leader Professor André de Villiers expressed enthusiasm about the chromatographic breakthroughs, emphasizing that the sensitive separation capabilities of 2D-LC opened the door to detecting previously hidden compounds. He remarked that the study underscores how much chemical diversity remains to be explored within Cannabis, especially in non-cannabinoid constituents that have historically been overlooked. The findings challenge the conventional focus on cannabinoids as the sole bioactive elements and raise important questions about the roles other metabolite classes, such as phenolics, might play in the plant’s pharmacology and therapeutic potential.
Significantly, this research suggests that Cannabis leaves, often classified as agricultural waste in many production systems, could serve as a rich source of bioactive phenolics, including these newly documented flavoalkaloids. Given the well-established bioactivities of flavonoids and alkaloids, their hybrid forms may exhibit novel pharmacological effects, potentially leading to new drug discovery opportunities. This prospect is particularly relevant as the global market for natural health products expands and the search intensifies for plant-derived antioxidants and anti-inflammatory agents.
Furthermore, the study’s revelation of substantial inter-strain chemical variability has profound implications for both Cannabis breeding and quality control. Understanding the phenolic profile diversity could facilitate the development of cultivars optimized not just for cannabinoid content but for a broader spectrum of medically relevant compounds. This approach could enrich the therapeutic portfolio of Cannabis-based preparations, enhancing their efficacy and safety through tailored phytochemical compositions verified by advanced analytical techniques.
Despite the excitement surrounding these discoveries, the researchers caution that further work is necessary to fully characterize the structural identities and bioactivities of the tentatively assigned flavoalkaloids. Future studies integrating synthetic chemistry, bioassays, and clinical evaluations will be essential to elucidate their mechanisms of action and therapeutic relevance. Nevertheless, this study lays a solid foundation by establishing robust methods and revealing a wealth of unexplored chemical entities in Cannabis phenolics.
This pioneering investigation into Cannabis phenolics aligns with a broader scientific trend emphasizing the complexity and multidimensionality of plant metabolomes. As metabolomics and separation science techniques evolve, previously neglected compound classes come into focus, reshaping our understanding of medicinal botanicals. The study from Stellenbosch University exemplifies this paradigm shift by marrying sophisticated chromatographic technology with insightful botanical research to unearth hidden treasures within one of the world’s most captivating plants.
In conclusion, the identification of flavoalkaloids in Cannabis leaves represents a major advancement in plant chemistry and phytopharmacology. It challenges existing dogmas by highlighting the rich diversity of non-cannabinoid compounds in Cannabis and their potential biomedical significance. As regulatory landscapes and consumer demand evolve, such discoveries herald a new era in Cannabis science where integrated chemical profiling guides both therapeutic innovation and sustainable cultivation strategies. This research, published in the Journal of Chromatography A, promises to catalyze further investigations and underscore the sophisticated chemical choreography embedded in nature’s pharmacopeia.
Subject of Research:
Not applicable
Article Title:
Comprehensive two-dimensional liquid chromatographic analysis of Cannabis phenolics and first evidence of flavoalkaloids in Cannabis.
News Publication Date:
2-Aug-2025
Web References:
Journal Article
DOI Link
References:
The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper.
Image Credits:
Magriet Muller
Keywords
Cannabis, Phenolics, Flavonoids, Flavoalkaloids, Two-dimensional liquid chromatography, Mass spectrometry, Analytical chemistry, Plant metabolites, Biomedical research, Chemical diversity, Pharmaceutical potential, Stellenbosch University
