Researchers at Stellenbosch University have discovered a rare group of phenolic compounds called flavoalkaloids in Cannabis leaves, which is a bit like finding out your discarded salad greens have been hiding a secret medical career.
In their study, the team analyzed three commercially grown Cannabis strains from South Africa and identified 79 phenolic compounds - 25 of which had never before been reported in the plant. Among these were 16 compounds tentatively classified as flavoalkaloids, a group so rare in nature that it basically qualifies as the plant world’s equivalent of a limited-edition collectible.
Dr. Magriet Muller, an analytical chemist at Stellenbosch University and the study’s first author, noted that studying plant phenolics is a nightmare because they show up in tiny amounts and have wildly diverse structures. “Most plants contain highly complex mixtures of phenolic compounds, and while flavonoids occur widely in the plant kingdom, the flavoalkaloids are very rare in nature,” she said. She also confessed that the team was stunned by the chemical variation between just three strains: “We did not expect such high variation in phenolic profiles between only three strains, nor to detect so many compounds for the first time in the species. Especially the first evidence of flavoalkaloids in Cannabis was very exciting.”
The secret to this discovery? Fancy new analytical methods combining comprehensive two-dimensional liquid chromatography with high-resolution mass spectrometry. Muller developed these techniques while working on rooibos tea, grapes, and wine before deciding to point them at Cannabis because, as she put it, “I knew it was a complex sample.”
Prof. André de Villiers, who led the study and heads the analytical chemistry research group at SU, explained that the advanced separation technology allowed the team to spot flavoalkaloids hiding among far more abundant flavonoids. He also highlighted the untapped potential of Cannabis leaves, which are currently regarded as waste. “Our analysis again highlights the medicinal potential of Cannabis plant material, currently regarded as waste. Cannabis exhibits a rich and unique non-cannabinoid phenolic profile, which could be relevant from a biomedical research perspective,” he said.
So, the next time you’re about to toss those cannabis leaves, remember: you might be discarding nature’s equivalent of a secret medical dossier. The findings were published in the Journal of Chromatography A.