Subclass of Terpenoids

Triterpenes

Thirty-carbon terpenes — the ursolic, boswellic, and quinovic acids and other resin and bitter principles.

Overview

About Triterpenes

Triterpenes are the thirty-carbon terpenes, formed when six isoprene units are assembled — in practice by the cyclization of squalene, the same precursor from which animals build cholesterol. Most fold into the familiar four- and five-ring frameworks: oleanane, ursane, lupane, dammarane, cucurbitane.

They are large, waxy, poorly water-soluble molecules, and they turn up wherever a plant needs a durable protective or structural chemistry — leaf cuticles, barks, resins and seed coats. Attach sugars to one and it becomes a saponin, which is why the two groups shade into each other.

Where Triterpenes Occur

Barks, waxy leaf surfaces and resins are the richest sources:

Frankincense (Boswellia)

the boswellic acids

Apple peel, rosemary, holy basil

ursolic acid

Olive leaf and many barks

oleanolic acid

Birch bark

betulin and betulinic acid

Cat's claw

the quinovic acid glycosides

Reishi and other medicinal fungi

the ganoderic acids

The free acids sit in the plant alongside their glycosides; whether a given monograph calls a compound a triterpene or a saponin usually comes down to whether the sugar is attached.

Pharmacological Importance

Anti-inflammatory activity dominates. The boswellic acids inhibit 5-lipoxygenase, a pathway distinct from the COX enzymes that NSAIDs target, which is the mechanistic argument for frankincense in inflammatory joint and bowel conditions. Ursolic and oleanolic acid show broad anti-inflammatory, hepatoprotective and — in ursolic acid's case — muscle-anabolic signals in preclinical work.

Betulinic acid is among the more-studied plant cytotoxic leads, and the ganoderic acids carry much of the pharmacology attributed to reishi.

Toxicity & Safety

The free triterpene acids are generally well tolerated and are consumed daily in ordinary foods — apple peel and olive oil among them.

Their practical limitation is not toxicity but bioavailability: these are large, greasy, poorly absorbed molecules, and many impressive in-vitro findings do not survive the journey through a human gut. Read plasma-level data before accepting a triterpene claim built on cell-culture concentrations.

Constituents

All Triterpenes

79 total Filter triterpenes

11-Keto-beta-boswellic acid 1 herb 13,18-Dehydroglaucarubinone 1 herb 2'-Acetylglaucarubinone 1 herb 3-Acetyl-beta-boswellic acid 1 herb

Acetyl-11-keto-beta-boswellic acid (AKBA) 1 herb Acetyl-beta-boswellic acid 1 herb Ailanthinone 1 herb alpha-Amyrin 2 herbs alpha-Boswellic acid 1 herb Arjungenin 1 herb Arjunic acid 1 herb Arjunolic acid 1 herb Asiatic acid 1 herb Asiaticin 1 herb Azadirachtin 1 herb Azadiradione 1 herb

Bayogenin 1 herb beta-Amyrin 2 herbs beta-Boswellic acid 1 herb Beta-resinic acid 1 herb Betulin 3 herbs Betulinic acid 10 herbs Brahmic acid 1 herb

Centellasapogenol A 1 herb

Open in filterable index

Source Plants

Herbs Containing Triterpenes

63 herbs

Plants in the materia medica documented to carry triterpenes, with the compounds each one is listed for. The bar counts how many DISTINCT triterpenes are on record for a plant, relative to the best-documented — it measures breadth of record, not potency, so a plant with one well-studied compound can outrank a richer source that has simply been analysed less. Where a measured concentration is on record it is quoted inline; most entries have none yet.