Geraniin (Dehydroellagitannin · Phyllanthus Marker · ACE Inhibitor Research)

Compound	Geraniin
Chemical class	Tannin — Dehydroellagitannin (hydrolysable tannin)
CAS	60976-49-0
Primary source	Phyllanthus niruri (Bhumi Amla), Phyllanthus urinaria; Geranium thunbergii
Key applications	ACE inhibition; antiviral (HSV); antioxidant; cytoprotective; urolithin precursor
Claim strength	Emerging
Typical form	Phyllanthus niruri (Bhumi Amla) extract — geraniin as characteristic ellagitannin
Buy from Herbuno	Bhumi Amla (Phyllanthus Niruri) Extract Powder → Bhumi Amla Liquid Extract (Water Soluble) - Phyllanthus niruri →

Name origin: Geraniin is named for Geranium thunbergii, the plant from which it was first characterised — a traditional Japanese antidiarrhoeal remedy. Structurally it is a dehydroellagitannin, a hydrolysable tannin distinguished by a dehydrohexahydroxydiphenoyl (DHHDP) group in place of the ordinary HHDP unit, which gives it a reactive, hydrated cyclohexenone motif and a chemistry rather more labile than that of the standard ellagitannins. Traditional use: Geraniin's principal source in commerce is Phyllanthus niruri (Bhumi Amla, "earth gooseberry"), a small herb with an extensive Ayurvedic and pan-tropical folk record — used for jaundice and liver complaints, for kidney and bladder stones, for diabetes, and for hypertension. Geranium thunbergii carries its own Japanese antidiarrhoeal tradition. The ACE-inhibitory activity of geraniin gives a mechanistic foothold for the antihypertensive strand of that ethnobotanical record. Research trajectory: Geraniin was isolated from Phyllanthus niruri and identified as an angiotensin-converting enzyme inhibitor in work on Paraguayan medicinal plants, connecting the compound directly to the plant's traditional use for hypertension Ueno (J Nat Prod). Its antiviral activity has been quantified: geraniin from Phyllanthus urinaria actively suppressed herpes simplex virus type 2 infection with a 50% inhibitory concentration of 18.4 micromolar, with no toxicity to host cells at antiviral concentrations Yang 2007. Its metabolic fate has also been mapped in detail — seven urinary and intestinal microbial metabolites were isolated from rats after geraniin ingestion and structurally determined as dibenzopyran (urolithin) derivatives Ito 2011. Commercial source: Bhumi Amla (Phyllanthus niruri) Extract Powder is available from Herbuno.

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Evidence for Geraniin Applications

ACE inhibition: Geraniin was isolated from Phyllanthus niruri and characterised as an angiotensin-converting enzyme inhibitor, a finding that gives a plausible mechanistic basis for the plant's traditional use in hypertension Ueno (J Nat Prod). This is an enzyme-level finding rather than clinical evidence of blood-pressure lowering in humans. Claim strength: Emerging.

Antiviral activity: Geraniin isolated from Phyllanthus urinaria suppressed herpes simplex virus type 2 infection in vitro with an IC50 of 18.4 ± 2.0 micromolar, while the co-occurring 1,3,4,6-tetra-O-galloyl-beta-D-glucose inhibited HSV-1 with an IC50 of 19.2 ± 4.0 micromolar; neither showed toxicity toward host cells at antiviral concentrations Yang 2007. The two compounds showed distinct selectivity between the virus types. Claim strength: Emerging.

Urolithin metabolites more active than the parent: After oral geraniin administration to rats, seven urinary and intestinal microbial metabolites were isolated and identified as dibenzopyran derivatives; four of these, prepared by synthesis, showed more potent antioxidant activity in the ORAC assay than intact geraniin or corilagin, and plasma ORAC scores rose with plasma metabolite concentration Ito 2011. This is direct evidence that the metabolites, not the parent tannin, carry the antioxidant effect in vivo. Claim strength: Emerging.

Broad preclinical activity: Geraniin is among the most-studied individual ellagitannins, with reported antioxidant, antimicrobial, anticancer, cytoprotective, immunomodulatory, and analgesic activities, and it is one of the ellagitannins whose hepatoprotective effects have been examined in models of ethanol-induced liver injury. Claim strength: Emerging.

Phyllanthus marker: Geraniin is the characteristic ellagitannin of Phyllanthus niruri and P. urinaria, making it the natural analytical marker for authenticating and standardising Bhumi Amla material Ueno (J Nat Prod)Yang 2007. Claim strength: Emerging.

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Dosage & Formulator Specification

No established human dose exists for isolated geraniin, and the evidence base is preclinical. It is delivered within the tannin fraction of Phyllanthus niruri extract, and the practical specification is total tannins or ellagitannins by HPLC, with geraniin quantified as the characteristic marker where a defined profile is required.

A species distinction is essential and is easily missed. Bhumi Amla is Phyllanthus niruri; Amla is Phyllanthus emblica (Indian gooseberry). These share a genus and a colloquial name fragment but are different plants with different chemistry — P. emblica is a vitamin-C and gallotannin source, while P. niruri is the geraniin-bearing herb. A buyer specifying "Phyllanthus extract" or even "Amla" and expecting geraniin would very likely receive the wrong material. Bhumi Amla (Phyllanthus niruri) Extract Powder and Bhumi Amla Liquid Extract are available from Herbuno and are the correct inputs.

Geraniin's chemistry has practical handling consequences. As a dehydroellagitannin bearing the reactive DHHDP group, it is more labile than the standard ellagitannins and is susceptible to hydrolysis and oxidation during extraction and storage; material intended to deliver defined geraniin content warrants controlled processing and batch-level assay rather than reliance on nominal figures.

The metabolism point deserves emphasis because it is unusually well established here. Geraniin is largely not absorbed intact; gut microbiota convert it to urolithin-type dibenzopyran metabolites, and those metabolites showed greater antioxidant activity than the parent compound, with plasma antioxidant capacity tracking metabolite concentration. The functional unit is therefore the metabolite, not the tannin, and effect depends on the consumer's microbiota — a point that should temper any claim built on in vitro activity of intact geraniin.

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Frequently Asked Questions — Geraniin

What is geraniin?
Geraniin is a dehydroellagitannin, a hydrolysable tannin first characterised from Geranium thunbergii and now best known as the characteristic ellagitannin of Phyllanthus species — notably Phyllanthus niruri (Bhumi Amla) and Phyllanthus urinaria. It is among the most-studied individual ellagitannins.

What is geraniin studied for?
Geraniin was identified as an angiotensin-converting enzyme (ACE) inhibitor from Phyllanthus niruri, which is of interest given the plant's traditional use for hypertension. It also shows antiviral activity: against herpes simplex virus type 2 it suppressed infection with an IC50 of about 18.4 micromolar without host-cell toxicity. Antioxidant, antimicrobial, and cytoprotective activities are also reported.

Which Herbuno product contains geraniin?
Bhumi Amla (Phyllanthus niruri) Extract Powder delivers geraniin as the characteristic ellagitannin of the plant, and Bhumi Amla Liquid Extract is a water-soluble alternative. Note that Bhumi Amla (Phyllanthus niruri) is a different plant from Amla (Phyllanthus emblica / Indian gooseberry), despite the shared genus.

How is geraniin metabolised?
Like other ellagitannins, geraniin is largely converted rather than absorbed intact. Seven urinary and intestinal microbial metabolites were isolated in rats after geraniin ingestion, all dibenzopyran derivatives — the urolithin class. Notably, these metabolites showed more potent antioxidant activity in the ORAC assay than intact geraniin or corilagin.

Related compounds: Corilagin, Ellagic Acid, Casuarictin, Galloylglucose

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Claim-strength scale – High = multiple human RCTs; Moderate = limited trials or strong preclinical convergence; Emerging = early-stage lab or animal data.

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