Perrottetinene Diol

Perrottetinene Diol at a Glance

Perrottetinene diol is a naturally occurring analogue of cannabidiol — and it is not made by cannabis. It comes from Radula marginata, a leafy liverwort endemic to New Zealand, and it was identified and fully characterised from nature for the first time in 2025 ^{1Reference 1Andre et al. · 2025Unique bibenzyl cannabinoids in the liverwort Radula marginata: parallels with Cannabis chemistry — phytochemistryView study →}.

That is a genuinely unusual thing to be able to say about a cannabinoid in the 2020s.

The molecule is a bibenzyl, not a terpenophenolic like the Cannabis cannabinoids, and it carries the trans configuration — hence trans-PTD — where the liverwort’s THC analogue perrottetinene is cis. Structurally it stands to CBD roughly as perrottetinene stands to THC: recognisably the same shape, arrived at by a different biosynthetic route.

★ What makes it interesting is not the molecule alone but the series it completes. R. marginata makes bibenzyl analogues of THC, CBD and CBG, each with its own acid precursor — and it occurs as three chemotypes dominated by one or another of them, in close analogy to the THC-, CBD- and CBG-dominant chemotypes of Cannabis ^{1Reference 1Andre et al. · 2025Unique bibenzyl cannabinoids in the liverwort Radula marginata: parallels with Cannabis chemistry — phytochemistryView study →}. Two distant plant lineages, separated by hundreds of millions of years, arrived at a parallel chemistry and a parallel population structure.

Its pharmacology is unknown. No receptor binding, no animal work, no toxicology — what follows is chemistry and natural history, because that is all there is.

What Is Actually Known

It exists, in quantity, and it varies. Across 75 wild collections from three locations and several seasons, perrottetinene diol ranged from undetectable to 10 mg/g of freeze-dried weight ^{1Reference 1Andre et al. · 2025Unique bibenzyl cannabinoids in the liverwort Radula marginata: parallels with Cannabis chemistry — phytochemistryView study →}. Its acid precursor, perrottetinene diol acid, ranges higher still.

It defines one of the plant’s three chemotypes. Sites are dominated by PET, by PTD, or by bibenzyl-4-geranyl — and those site-selective chemotypes persisted under artificial lighting and in in-vitro progeny, which points at genetic control rather than an environmental response ^{1Reference 1Andre et al. · 2025Unique bibenzyl cannabinoids in the liverwort Radula marginata: parallels with Cannabis chemistry — phytochemistryView study →}.

Cultivation raises it. Twelve months of controlled growth took one PTD-chemotype line from 5.0 to 25.2 mg/g of total cannabinoids, with the increase coming mainly through PTD and its acid, and through the CBG analogue and its acid ^{1Reference 1Andre et al. · 2025Unique bibenzyl cannabinoids in the liverwort Radula marginata: parallels with Cannabis chemistry — phytochemistryView study →}.

And that is the extent of it. Everything above is compositional. Nothing has been tested for activity.

Why It Is Not Simply “Liverwort CBD”

Two cautions belong on any page about this molecule, and both are about restraint.

CBD’s pharmacology does not transfer. Structural analogy is not pharmacological equivalence, and CBD’s own profile is complicated — it is not a straightforward CB1 or CB2 agonist, and much of what it does runs through other targets entirely. Nothing licenses reading any of that onto PTD. The one liverwort cannabinoid that has been characterised, perrottetinene, turned out to differ from its cannabis counterpart in a way nobody predicted: it suppressed brain prostaglandins where THC did not ^{2Reference 2Chicca et al. · 2018In vitroUncovering the psychoactivity of a cannabinoid from liverworts associated with a legal high — in vitro and animalView study →}.

The plant is not a cannabinoid source in any practical sense. Total bibenzyl cannabinoids across those 75 wild samples ran 3.1–24.4 mg/g — roughly 0.3–2.4% of freeze-dried weight, an order of magnitude below cannabis THC ^{1Reference 1Andre et al. · 2025Unique bibenzyl cannabinoids in the liverwort Radula marginata: parallels with Cannabis chemistry — phytochemistryView study →}. And the plant’s major bibenzyls are not cannabinoids at all: the 2-prenylated bibenzyls BB2P and BB2G together make up most of the total, and neither is psychoactive ^{1Reference 1Andre et al. · 2025Unique bibenzyl cannabinoids in the liverwort Radula marginata: parallels with Cannabis chemistry — phytochemistryView study →}. A “high-bibenzyl” extract is not a high-cannabinoid one.

Prevalence in Nature

So far, one organism: Radula marginata, a leafy liverwort found nowhere in the world but New Zealand, growing as an epiphyte on tree bark in the shaded, dripping interior of native forest.

The cannabinoids sit in the plant’s oil bodies. Perrottetinene itself also occurs in the Japanese R. perrottetii, R. campanigera and R. chinensis and in the Costa Rican R. laxiramea — so a “Radula” claim is not automatically an R. marginata claim — but perrottetinene diol has been characterised only from R. marginata ^{1Reference 1Andre et al. · 2025Unique bibenzyl cannabinoids in the liverwort Radula marginata: parallels with Cannabis chemistry — phytochemistryView study →}.

This matters for sourcing, because the plant is listed as at risk and declining in its only habitat, largely because of collection.

Discovery & Synthesis

The liverwort cannabinoids have a slow history. Perrottetinene was reported from R. marginata in 2002 ^{3Reference 3Toyota et al. · 2002New bibenzyl cannabinoid from the New Zealand liverwort Radula marginata — phytochemistryView study →}, and it took until 2018 for total synthesis to establish that it was genuinely psychoactive ^{2Reference 2Chicca et al. · 2018In vitroUncovering the psychoactivity of a cannabinoid from liverworts associated with a legal high — in vitro and animalView study →}. R. marginata was meanwhile being sold as a legal cannabis substitute — for years before anyone knew whether it did anything.

Perrottetinene diol arrived at the end of that sequence, in 2025, in a survey that set out to map the plant’s full cannabinoid inventory rather than to chase the THC analogue ^{1Reference 1Andre et al. · 2025Unique bibenzyl cannabinoids in the liverwort Radula marginata: parallels with Cannabis chemistry — phytochemistryView study →}. The work was carried out in collaboration with Māori kaitiaki — indigenous guardians — which is worth recording as part of how the molecule reached the literature.

Its acid precursor was characterised in the same paper, and the pairing is the point: like Cannabis, this liverwort makes its cannabinoids as acids and they decarboxylate to the neutral forms.

Toxicity & Safety

Safety at a Glance

❔ Toxicity unknown

• Nothing is known. No toxicology, no receptor pharmacology, no animal study, no human exposure data. This is not a molecule with a reassuring safety record — it is one with no record at all.
• The source plant is psychoactive through a different molecule, perrottetinene, which produces the full cannabinoid tetrad in mice ^{2Reference 2Chicca et al. · 2018In vitroUncovering the psychoactivity of a cannabinoid from liverworts associated with a legal high — in vitro and animalView study →}. Anyone taking the plant is taking both.
• Do not infer safety from CBD. The structural analogy has never been shown to extend to pharmacology, and the plant’s THC analogue already broke that assumption once.

Full Safety Detail

The honest position is that this molecule has been measured and not tested. The 2025 paper characterised it, quantified it across 75 collections and showed how cultivation changes its abundance ^{1Reference 1Andre et al. · 2025Unique bibenzyl cannabinoids in the liverwort Radula marginata: parallels with Cannabis chemistry — phytochemistryView study →}. It did not assess activity, and no subsequent work has.

What can be said is about the plant rather than the molecule. Radula marginata is genuinely psychoactive and completely unstudied in people, and it was sold as a legal high for years before its pharmacology was known. Perrottetinene diol is one of several cannabinoids in it, and any exposure to it has been incidental to that.

What was not assessed: everything. No acute or chronic toxicity, no receptor profile, no pharmacokinetics, no reproductive study, no interaction work. The absence of reported harm reflects the absence of anyone looking.

Dosage

There is no dose. Perrottetinene diol has never been administered to an animal or a person in any published study.

The figures above — ND–10 mg/g freeze-dried weight, and the cultivation increase to 25.2 mg/g total cannabinoids — are plant-content measurements, not quantities anyone has taken. Converting a content figure into a dose would require knowing what the molecule does, and nobody does.

References

1. Andre, C. M., Sansom, C. E., Plunkett, B. J., et al. (2025). Unique bibenzyl cannabinoids in the liverwort Radula marginata: parallels with Cannabis chemistry — phytochemistry. New Phytologist. https://pubmed.ncbi.nlm.nih.gov/39716766/
2. Chicca, A., Schafroth, M. A., Reynoso-Moreno, I., et al. (2018). Uncovering the psychoactivity of a cannabinoid from liverworts associated with a legal high — in vitro and animal. Science Advances. https://pubmed.ncbi.nlm.nih.gov/30397641/
3. Toyota, M., Shimamura, T., Ishii, H., et al. (2002). New bibenzyl cannabinoid from the New Zealand liverwort Radula marginata — phytochemistry. Chemical & Pharmaceutical Bulletin. https://pubmed.ncbi.nlm.nih.gov/12372871/