marrubiin
compound / compound-marrubiin
マルビイン
Marrubiin is a labdane-type diterpene whose role in white horehound bitterness is documented in an official assessment report.
On this page (7 sections)
Reading the bitterness
Marrubiin is a labdane-type diterpene found in the dried flowering aerial parts of white horehound (Marrubium vulgare). The EMA (European Medicines Agency) assessment report systematizes that the dried flowering aerial parts are bitter and that marrubiin, a furan-type labdane diterpene, contributes to that bitterness.
A 2020 review reports marrubiin as the characteristic labdane-type diterpene of white horehound within a content range of 0.12–1%. The same review assigns a bitter value of 3.0 to white horehound and describes it as a stimulator of bitter taste receptors at the base of the tongue. However, what standard or calculation method this bitter value is based on cannot be determined from this description alone.
A 2013 review describes marrubiin as 「ホワイトホアハウンドをはじめ多くの薬用植物に苦味をもたらす、広く知られたジテルペノイドラクトンである」 (in translation: "a widely known diterpenoid lactone that brings bitterness to white horehound and many other medicinal plants"). These sources are all reviews and assessment reports that organize existing literature, not independent sensory testing or quantitative analysis.
Within the scope of an abstract, addition of beta-cyclodextrin to white horehound mother tincture reduced the bitterness direction as measured by electronic tongue. GC-MS analysis confirmed formation of an inclusion complex between beta-cyclodextrin and marrubiin. Of the 5 herbal tinctures tested (white horehound, propolis, thyme, plantain, and eucalyptus), the bitterness-reducing effect of beta-cyclodextrin was greatest in the white horehound tincture. This assessment is by electronic tongue, and the authors state that quantitative assessment of bitterness cannot be performed.
The same review reports the total content of labdane-type diterpenes at up to 3 mg/g of fresh weight, with marrubiin as the main component and its precursor pre-marrubiin also present at 0.13%. These values are drawn from prior literature by the review, and the primary measurement conditions (source, extraction method, etc.) cannot be determined from the review description alone.
Sources for this overview
Assessment report on Marrubium vulgare L., herba
Checked for this overview: The assessment report's description of contribution to bitterness is adopted.
Marrubium vulgare L.: A Phytochemical and Pharmacological Overview
Checked for this overview: The bitter value of 3.0 and content of 0.12–1% are adopted. / Total labdane-type diterpenes and pre-marrubiin 0.13%, and description of bitter accompanying aroma after drying.
Checked for this overview: The review description of bitter component is adopted.
Checked for this overview: Measurement of bitterness reduction by beta-cyclodextrin and formation of inclusion complex.
Follow the connections
horehound →— major bitter compound→ marrubiin
marrubiin →can be debittered by→ cyclodextrins
Structured claims — open a section to read each claim's confidence, evidence and limits
Composition and content (2)
Scope: The dried flowering aerial parts of Marrubium vulgare
Note: The EMA assessment report records its role in bitterness and a standard of 0.7% or more in the dried herbal drug. This is not a recommendation for culinary use.
Show data
spice-horehound —has_major_bitter_compound→ compound-marrubiinScope: Layer: literature. Description from the Composition section of an existing academic review (Aćimović et al. 2020, Molecules).
Show data
spice-horehound —has_composition→ compound-marrubiinSensory (1)
Scope: Layer: solution. PCA analysis using an Alpha Astree II electronic tongue (7 potentiometric sensors). Caffeine was used as the standard for the bitterness direction. The authors state that the electronic-tongue data cannot provide a quantitative assessment of bitterness.
Show data
compound-marrubiin —can_be_debittered_by→ compound-class-cyclodextrins