Monkshood and larkspur are two of the more dangerous plants a gardener can grow. They also produce a family of chemically complex compounds called diterpenoid alkaloids that researchers have wanted to study for decades and have struggled to obtain in usable quantities.
A team led by Michigan State University, working with the Czech Academy of Sciences, has now mapped the first stretch of the assembly line. Six enzymes, working in sequence, build a diterpenoid alkaloid called atisinium.
The findings were published in Molecular Plant. This is basic biochemistry. No drug candidate emerged from it, and the compound has not been tested as a treatment for anything.
The Reason These Compounds Have Been Hard to Study
Plants make specialized metabolites slowly and in tiny amounts. Extracting a compound from a plant that produces very little of it, and that is also toxic to handle, is a poor foundation for research at any scale.
Total chemical synthesis is not a workable alternative for this family either. The structural complexity of diterpenoid alkaloids has defeated attempts to build them from scratch. Aconitine, one of the best-known members of the family, was isolated nearly 200 years ago and still has not been successfully synthesized in a laboratory.
That leaves a third route: identify the enzymes the plant uses and transfer the genetic instructions into a host organism that grows quickly and safely.
"These plants have been used in different forms of medicine throughout the world for thousands of years," said Garret Miller, an MSU alum and co-first author of the paper who is now an assistant professor of biotechnology at the University of Michigan-Flint, in the university's announcement.
The collaboration itself started at a conference. Björn Hamberger, whose MSU lab led the work, met researchers from Tomáš Pluskal's laboratory at the Czech Academy of Sciences, who were pursuing the same compounds in wolfsbane. "When this happens, we can either go our own ways, or come together, and it's joining up that always leads to the best science," Hamberger said.
The Search and the Missing Piece
Finding the enzymes meant a genetic search across species. The team compared which genes switched on in which tissues across multiple larkspur and wolfsbane species, then tested candidates by inserting genes into tobacco plants and analyzing what those plants produced. One by one, the tobacco showed which components were required.
Six enzymes emerged from Siberian larkspur and garden monkshood: a pair of terpene synthases, three cytochrome P450 enzymes, and a reductase, according to the preprint version of the work. That last one was the difficult find. It bears little resemblance to previously characterized enzymes. The team located it through coexpression analysis, betting that genes switching on alongside the ones already identified signaled shared function.
Two features of the pathway stood out. The enzymes helped the compound fold into its complex final shape, and they facilitated the addition of a nitrogen source the researchers described as crucial and unexpected. Nitrogen incorporation is what makes an alkaloid an alkaloid, and where it comes from in this family had not been established.
MedicalDaily Evidence Check
This is plant biochemistry, not medicine. The study characterized enzymes and reconstituted part of a pathway in tobacco. There were no cells tested for therapeutic activity, no animals and no patients.
Atisinium is described in the literature as a bioactive diterpenoid alkaloid and a likely entry point toward more complex members of the family. Bioactive means it does something in a biological system. It does not mean beneficial, and in this plant family the same chemistry produces aconitine, a compound notorious for severe cardiac and neurological toxicity.
That is the honest tension in the story. Some coverage has framed these plants as pointing toward new pain, malaria, or cancer medicines. Diterpenoid alkaloids have attracted research interest partly for effects on ion channels relevant to pain signaling, but no member of the family is an approved drug in the United States, and the toxicity of related compounds is precisely why controlled production matters.
The paper reports the entry steps of the pathway, not the complete route to any specific compound of therapeutic interest. More enzymes remain to be found.
The Practical Case for Mapping Pathways
The reason this kind of work gets funded is supply, safety, and consistency.
Once a pathway is solved, the genes can be inserted into an engineered host such as yeast, which grows in a fermenter on a predictable schedule. That removes dependence on harvesting a toxic plant, removes the seasonal and geographic variability of plant material, and produces a defined product rather than a crude extract of uncertain composition.
Precedent exists across pharmacology. Several plant-derived medicines that were once limited by scarce or endangered source material have moved toward biosynthetic or semisynthetic production once their pathways were understood.
"Our vision is to provide green, sustainable tools that will allow us harness these plants' natural power," Hamberger said.
A Word About the Plants Themselves
Because this research names two common garden plants, one practical safety note belongs here.
Monkshood, also called wolfsbane or aconite, is among the most poisonous plants commonly grown in ornamental gardens. Its toxins can be absorbed through skin contact with cut or damaged plant material, and ingestion of even small amounts has caused fatal cardiac arrhythmias. Larkspur is also toxic to people and livestock.
Neither should be handled without gloves, and neither should ever be consumed in any preparation. Aconite preparations are sold in some traditional medicine contexts, and poisonings from them are documented in the medical literature. Anyone who suspects an exposure should contact Poison Control at 1-800-222-1222 immediately rather than waiting for symptoms, because cardiac effects can develop rapidly.
Nothing in this research suggests any home or supplement use. The entire point of mapping the pathway is to eventually produce specific compounds under controlled conditions precisely because the plants themselves are dangerous.
What comes next is the remainder of the pathway. Knowing the entry steps gives researchers a foothold toward the more complex diterpenoid alkaloids that have drawn interest, and toward engineering a host organism that can make them reliably. That work is ongoing and measured in years.
Frequently Asked Questions
What did the researchers discover? The six enzymes that Siberian larkspur and garden monkshood use to build a diterpenoid alkaloid called atisinium, including a reductase with little resemblance to previously characterized enzymes.
Where was the research published? In the journal Molecular Plant, by a team led by Michigan State University in collaboration with the Czech Academy of Sciences.
Is this a new drug? No. This is basic plant biochemistry. No drug candidate was produced, and atisinium has not been tested as a treatment.
Why does mapping the pathway matter? Because the genes can potentially be transferred into an engineered host such as yeast, allowing controlled production without harvesting toxic plants and with more consistent purity.
Are these plants dangerous? Yes. Monkshood is among the most poisonous ornamental garden plants, with toxins absorbable through skin contact with damaged material and ingestion linked to fatal cardiac arrhythmias. Larkspur is also toxic.
Should anyone use these plants medicinally? No. Aconite poisonings are documented in the medical literature. Suspected exposure warrants an immediate call to Poison Control at 1-800-222-1222.
What happens next in this research? Identification of the remaining enzymes in the pathway and engineering of a host organism capable of producing the compounds reliably.
