Galloylglucose (Core Gallotannin · Ellagitannin Precursor)

Compound	Galloylglucose series (beta-glucogallin → pentagalloylglucose / PGG)
Chemical class	Tannin — Gallotannin (galloyl esters of D-glucose)
CAS	14937-32-7 (1,2,3,4,6-penta-O-galloyl-beta-D-glucose)
Primary source	Terminalia chebula (Haritaki); Quercus infectoria galls; Rhus galls; Phyllanthus emblica
Key applications	Core gallotannin; ellagitannin biosynthetic precursor; carbohydrase inhibition; antiviral research
Claim strength	Moderate (chemistry); Emerging (bioactivity)
Typical form	Gallotannin-standardised extract (Tannins 50%, Terminalia chebula)
Buy from Herbuno	Tannins 50% Powder (Haritaki Extract) | Standardized Terminalia Chebula → Terminalia Chebula (Haritaki) Extract Powder →

Name origin: Galloylglucose is simply descriptive — glucose bearing galloyl (gallic acid) ester groups. The series is defined by how many: beta-glucogallin carries one, and the sequence builds through di-, tri-, and tetra-galloylglucoses to 1,2,3,4,6-penta-O-galloyl-beta-D-glucose (PGG), the pentagalloyl ester that is the archetypal gallotannin and the substance from which tannic acid and the higher gallotannins are elaborated. These are the simplest of the hydrolysable tannins and, chemically speaking, the foundation of the whole class. Traditional use: Gallotannin-rich materials have vast traditional and industrial histories: Terminalia chebula (Haritaki) is one of the three fruits of Ayurvedic triphala and among the most-used botanicals in that tradition; oak and sumac galls have been used for millennia for tanning leather, for ink-making, and as astringent medicines. In every case the astringency, the tanning capacity, and the ink chemistry trace to the same galloylglucose backbone. Research trajectory: The galloylglucoses matter first as biosynthetic precursors: the hexahydroxydiphenoyl (HHDP) unit that defines every ellagitannin is formed by intramolecular oxidative C-C coupling of neighbouring galloyl residues on a galloylglucose Klewicka 2018, and pentagalloylglucose is the branch point from which tellimagrandin II, casuarictin, pedunculagin, and eventually the C-glucosidic ellagitannins castalagin and vescalagin are built. As bioactives they have been studied directly: beta-glucogallin and both anomers of pentagalloylglucose were evaluated alongside fourteen C-glucosidic ellagitannins for alpha-glucosidase and alpha-amylase inhibition as potential antidiabetic functional food ingredients Cardullo 2020, and 1,3,4,6-tetra-O-galloyl-beta-D-glucose from Phyllanthus urinaria inhibited herpes simplex virus type 1 with an IC50 of 19.2 micromolar without host-cell toxicity Yang 2007. Commercial source: Tannins 50% Powder (standardised Terminalia chebula) is available from Herbuno.

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Evidence for Galloylglucose Applications

Biosynthetic foundation of the hydrolysable tannins: The HHDP group that defines the ellagitannins is formed by intramolecular oxidative carbon-carbon coupling of suitably oriented neighbouring galloyl residues on galloylglucoses Klewicka 2018; pentagalloylglucose is therefore the precursor from which the entire ellagitannin family — casuarictin, sanguiin H-6, castalagin, vescalagin — is elaborated. Understanding the galloylglucoses is prerequisite to understanding every other tannin in this batch. Claim strength: Moderate (chemistry).

Carbohydrase inhibition: Beta-glucogallin, beta-pentagalloylglucose, and alpha-pentagalloylglucose were evaluated alongside C-glucosidic ellagitannins for inhibition of alpha-glucosidase and alpha-amylase, in a study explicitly framed around their potential as functional food ingredients with antidiabetic properties Cardullo 2020. These are in vitro enzyme studies; they do not constitute clinical evidence of glycaemic effect. Claim strength: Emerging.

Antiviral activity: 1,3,4,6-Tetra-O-galloyl-beta-D-glucose, isolated from Phyllanthus urinaria, effectively inhibited herpes simplex virus type 1 infection in vitro with an IC50 of 19.2 ± 4.0 micromolar and no toxicity toward host cells at antiviral concentrations — notably showing selectivity for HSV-1 where the co-occurring geraniin was selective for HSV-2 Yang 2007. Claim strength: Emerging.

Astringency and protein binding: The defining functional property of the gallotannins is their capacity to bind and precipitate proteins, which is the basis of astringency, of leather tanning, and of the traditional use of gall preparations as topical astringents. This protein-binding behaviour scales with the degree of galloylation, so the position of a material within the galloylglucose series determines its practical behaviour. Claim strength: Moderate.

Source distribution: Galloylglucoses dominate the tannin fraction of Terminalia chebula (Haritaki), oak and sumac galls, and Phyllanthus emblica, making these the practical commercial sources of gallotannin material, in contrast to the ellagitannin-dominated pomegranate and Rubus materials. Claim strength: Moderate.

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Dosage & Formulator Specification

The galloylglucoses are a compositional series rather than a single compound, and no isolated human dosing standard exists for any individual member. Material is specified and supplied as total tannins or total gallotannins — Tannins 50% Powder (standardised Terminalia chebula) is available from Herbuno, with Terminalia Chebula (Haritaki) Extract Powder as the whole-extract alternative.

Formulators should understand what "tannins 50%" describes. It is a total hydrolysable tannin figure, not a statement about which galloylglucoses are present or in what proportion; the degree of galloylation varies with source and processing, and the mono- through penta-galloyl species behave differently. Where a defined gallotannin profile matters — for astringency, for protein-binding capacity, or for a specific bioactivity — individual galloylglucose quantification by HPLC or LC-MS is necessary rather than reliance on the total figure alone.

Protein binding is the practical formulation issue that dominates all others. Gallotannins bind and precipitate proteins, which is precisely why they tan leather and why they taste astringent. In a formulation this means real incompatibility risk with protein ingredients, with gelatin capsules, and with certain enzymes, and it also means gallotannins can reduce the bioavailability of dietary protein and of some minerals, notably iron. Any product combining a high-tannin extract with a protein or mineral component needs to be evaluated for these interactions rather than assumed compatible.

This monograph documents the galloylglucose series as a formulator reference within the HerbIQ index, positioning it as the biosynthetic and chemical foundation beneath the ellagitannins — casuarictin, sanguiin H-6, geraniin, castalagin, and vescalagin — documented alongside it in this batch, and connecting to gallic acid, tannic acid, and the chebulic tannins elsewhere in the library.

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Frequently Asked Questions — Galloylglucose

What are the galloylglucoses?
The galloylglucoses are the core gallotannins — glucose esterified with one to five (or more) galloyl groups. The series runs from beta-glucogallin (1-O-galloyl-glucose) through to pentagalloylglucose (PGG), and they are both the simplest hydrolysable tannins and the biosynthetic precursors of the more complex ellagitannins.

Why do galloylglucoses matter biosynthetically?
They are the starting point of the entire hydrolysable tannin pathway. The hexahydroxydiphenoyl (HHDP) group that defines the ellagitannins is formed by intramolecular oxidative carbon-carbon coupling of two suitably oriented neighbouring galloyl residues on a galloylglucose. Pentagalloylglucose is the branch point from which ellagitannins such as tellimagrandin II, casuarictin, and ultimately castalagin are elaborated.

Which Herbuno product contains galloylglucoses?
Tannins 50% Powder (Standardized Terminalia chebula / Haritaki) delivers galloylglucoses within the standardised gallotannin fraction, and Terminalia Chebula (Haritaki) Extract Powder is the whole-extract alternative.

What are galloylglucoses studied for?
Beta-glucogallin and both anomers of pentagalloylglucose have been examined for alpha-glucosidase and alpha-amylase inhibition as potential functional food ingredients with antidiabetic properties. Individual galloylglucoses also show antiviral activity — 1,3,4,6-tetra-O-galloyl-beta-D-glucose inhibited herpes simplex virus type 1 in vitro.

Related compounds: Gallic Acid, Casuarictin, Geraniin, Castalagin

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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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