Perrottetinene Diol Acid

Perrottetinene Diol Acid at a Glance

Perrottetinene diol acid is the acid precursor of perrottetinene diol, the liverwort’s analogue of CBD. It stands to that molecule as CBDA stands to CBD: it is the form the plant actually synthesises, and it loses its carboxyl group to give the neutral cannabinoid on heating, drying or storage.

★ It is also the most abundant cannabinoid in the plant. Across 75 wild collections of Radula marginata it ranged from undetectable to 17 mg/g of freeze-dried weight — the widest range and the highest ceiling of any of the six bibenzyl cannabinoids measured ^{1Reference 1Andre et al. · 2025Unique bibenzyl cannabinoids in the liverwort Radula marginata: parallels with Cannabis chemistry — phytochemistryView study →}.

That combination is worth stating plainly. The molecule present in the largest quantity in this plant is the one nobody has tested.

Both it and the neutral form were 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 →}, which makes this one of the more recently described cannabinoids in the literature — and one made by a bryophyte rather than by cannabis.

The Acid Form Is the Real One

Plants make cannabinoids as acids. Cannabis makes THCA and CBDA, not THC and CBD; the neutral forms appear when the acids decarboxylate under heat, light and time. Radula marginata does the same thing with a different chemical skeleton — it builds bibenzyl cannabinoids, each with a matching acid ^{1Reference 1Andre et al. · 2025Unique bibenzyl cannabinoids in the liverwort Radula marginata: parallels with Cannabis chemistry — phytochemistryView study →}.

That has a practical consequence for anything measured in this plant. A fresh sample and a dried, aged or heated one are chemically different, and where the boundary sits between PTDA and PTD in a given batch depends on how the material was handled after collection. The published content figures are for freeze-dried tissue, which preserves the acids.

It also means the two molecules should not be summed casually. They are a precursor–product pair, and reporting “total PTD” without saying which form was measured describes a processing history as much as a plant.

What Is Actually Known

Its abundance and its variability, and nothing else.

PTDA ranges ND–17 mg/g of freeze-dried weight across wild sites and seasons ^{1Reference 1Andre et al. · 2025Unique bibenzyl cannabinoids in the liverwort Radula marginata: parallels with Cannabis chemistry — phytochemistryView study →}. Total bibenzyl cannabinoids in the same survey ran 3.1–24.4 mg/g — an eight-fold range, and roughly an order of magnitude below cannabis THC content.

Cultivation raises it substantially. A PTD-chemotype line grown for twelve months under controlled conditions went from 5.0 to 25.2 mg/g total cannabinoids, and the increase came mainly through PTD/PTDA and the CBG analogue and its acid ^{1Reference 1Andre et al. · 2025Unique bibenzyl cannabinoids in the liverwort Radula marginata: parallels with Cannabis chemistry — phytochemistryView study →}. So this molecule is one of the two that respond most to growing the plant deliberately.

No pharmacology of any kind has been reported — no receptor binding, no cell assay, no animal work.

Prevalence in Nature

Radula marginata alone, so far — a leafy liverwort that grows nowhere in the world but New Zealand, as an epiphyte on tree bark in shaded, humid native forest.

The plant occurs as three chemotypes, dominated respectively by perrottetinene, perrottetinene diol or bibenzyl-4-geranyl, and those chemotypes persist under artificial light and in in-vitro progeny — evidence of 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 →}. PTDA is the acid partner of the second of those three.

The species is at risk and declining in its only habitat, largely because of collection pressure.

Toxicity & Safety

Safety at a Glance

❔ Toxicity unknown

• Nothing is known. No toxicology, no receptor data, no animal or human exposure study.
• This is the plant’s most abundant cannabinoid, so anyone taking Radula marginata is likely taking more of this molecule than of any other — with no information at all about what it does.
• Do not infer safety from CBDA or CBD. Neither the structure nor the pharmacology has been shown to carry across.

Full Safety Detail

Cannabinoid acids are, as a general rule, much weaker at cannabinoid receptors than the neutral forms they decarboxylate into. That is true of THCA against THC, and it is the reason raw cannabis is not intoxicating. It would be a reasonable prior for PTDA — but it is a prior, not a finding, and it has never been tested in this molecule or this genus.

What is known about the plant applies here. Radula marginata is genuinely psychoactive through perrottetinene, was sold as a legal cannabis substitute for years before that was established, and has never been studied in a person in any form ^{2Reference 2Chicca et al. · 2018In vitroUncovering the psychoactivity of a cannabinoid from liverworts associated with a legal high — in vitro and animalView study →}.

What was not assessed: everything. No acute or chronic toxicity, no receptor profile, no pharmacokinetics, no reproductive or interaction work.

Dosage

No dose exists. Nothing has been administered to any animal or person in a published study.

The figures above are plant-content measurements of freeze-dried tissue — not quantities anyone has taken, and not convertible into one without knowing what the molecule 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/