Last updated on June 28, 2026 · Originally published June 16, 2026
You already know cannabis is chemically complex. Hundreds of cannabinoids, dozens of terpenes, flavonoids that most people haven’t even heard of. But a new study out of South Africa just added a whole new chapter — one hiding in the part of the plant most growers throw straight in the compost.
Researchers at Stellenbosch University have identified 16 compounds called flavoalkaloids in cannabis leaves for the first time ever. These aren’t minor variations on molecules scientists already knew about. Flavoalkaloids are a hybrid class — part flavonoid, part alkaloid — that are so rare in nature that finding them in cannabis at all came as a genuine surprise to the team that discovered them.
What are flavoalkaloids, and why does it matter?
Flavonoids themselves aren’t new to cannabis science. They’re the phenolic compounds that give plants their pigment, contribute to taste, and have attracted serious medical interest for their antioxidant, anti-inflammatory, and anti-carcinogenic properties. You’ll find flavonoids in rooibos tea, grapes, dark chocolate — and yes, cannabis, where compounds like cannflavin A and B have been studied for their anti-inflammatory effects that may exceed even ibuprofen’s on a per-milligram basis.
Flavoalkaloids take that chemistry further. They’re a fusion molecule — structurally distinct from pure flavonoids — and they show up rarely in the plant kingdom. That’s what made their detection in cannabis leaves so unexpected.
The Stellenbosch team, led by Dr. Magriet Muller and Prof. André de Villiers, analyzed three commercially grown South African cannabis strains. They mapped 79 phenolic compounds in total. Twenty-five of those had never been reported in cannabis before. The 16 flavoalkaloids were concentrated mainly in the leaves of just one strain — a detail that hints at how dramatically the chemistry can vary between cultivars, even within the same species.
The tool that made it possible
These compounds weren’t hiding because nobody looked. They were hidden because finding them requires unusually sophisticated analytical chemistry. Flavoalkaloids occur in tiny amounts and their structures closely resemble other flavonoids, making them easy to miss with standard screening methods.
Dr. Muller developed the detection approach as part of her postgraduate work — a combination of comprehensive two-dimensional liquid chromatography with high-resolution mass spectrometry. She had previously applied it to rooibos and wine. Cannabis, she noted, proved to be a far more complex sample than either. The two-dimensional separation was essential: without it, the rare flavoalkaloids would have been buried under the far more abundant flavonoids and never resolved.
What gets thrown away might be where the value is
Most cannabis research — and most commercial attention — has stayed close to the cannabinoids. THC. CBD. CBG. The compounds that produce direct psychoactive or therapeutic effects are the obvious targets. The rest of the plant, particularly the leaves, tends to be treated as agricultural waste.
Prof. de Villiers put it plainly: the discovery “highlights the medicinal potential of Cannabis plant material, currently regarded as waste.” That’s a significant reframe. If the leaves of even one strain are producing novel flavoalkaloids with potential biomedical relevance, the question becomes what other cultivars might be carrying — and what targeted breeding programs might eventually unlock.
It also raises the entourage effect question from a new angle. The idea that cannabinoids work better in the presence of terpenes and other plant compounds is already well established in the research literature. Flavonoids are thought to be part of that picture too. If flavoalkaloids turn out to have their own biological activity — still to be determined, since this study characterized the compounds rather than testing their effects — they could add another dimension to that interaction.
The practical applications are a long way off. Identifying a compound and understanding what it does in the human body are very different problems. But this kind of foundational chemistry work is exactly what that pipeline depends on.
For now, the takeaway is a familiar one in cannabis science: the plant keeps revealing complexity that the research field hasn’t caught up with yet. And the part of it that’s been going into the bin may deserve a second look.
Source: Muller et al., Journal of Chromatography A, 2025 (published May 2026 via Stellenbosch University).
