Subclass of Phenolics

Phenylpropanoids

Cinnamic-acid-derived aromatics — eugenol, anethole, the kavalactones, and the verbascoside-type glycosides.

Overview

About Phenylpropanoids

Phenylpropanoids are built on a C6–C3 unit — an aromatic ring with a three-carbon tail — derived from phenylalanine by the enzyme that opens the whole pathway, phenylalanine ammonia-lyase. Almost every other phenolic on this site descends from this step.

Under the heading here sit the compounds that keep the C6–C3 shape more or less intact: the aromatic allylbenzenes and propenylbenzenes of spice oils, the kavalactones, and the phenylethanoid glycosides of the verbascoside type.

Where Phenylpropanoids Occur

This is the chemistry of the spice rack, plus a set of glycosides from the figwort and olive families:

Clove, cinnamon leaf, basil

eugenol

Anise, fennel, star anise

trans-anethole

Tarragon and basil

estragole (methyl chavicol)

Nutmeg, sassafras, calamus

myristicin, safrole, the asarones

Kava

the kavalactones

Mullein, lemon verbena, olive

verbascoside and the phenylethanoid glycosides

Pharmacological Importance

Eugenol is a genuine local anaesthetic and antiseptic, still used in dentistry, and the reason clove oil is the traditional toothache remedy. Anethole is antispasmodic and carminative — the basis of the aniseed and fennel digestives — and mildly estrogenic.

The kavalactones are the anxiolytic actives of kava, working through GABA-A modulation and sodium-channel blockade without the tolerance profile of benzodiazepines. The phenylethanoid glycosides are potent antioxidants and anti-inflammatories in their own right.

Toxicity & Safety

This class contains the clearest genotoxic carcinogens in ordinary herbal use, and they should be named plainly. Safrole, estragole and methyleugenol are metabolically activated to DNA-reactive intermediates and are hepatocarcinogenic in rodents; safrole is banned as a food additive, and regulators have restricted the others. This is why sassafras is no longer used internally and why calamus varieties are distinguished by their beta-asarone content.

The doses involved are far above culinary exposure — using tarragon or basil in cooking is not the concern — but concentrated essential oils and long-term high-dose use of these specific oils are. Kava carries a separate and unresolved hepatotoxicity signal that tracks with aerial-part constituents, cultivar and solvent extraction rather than with traditional water-based root preparations.

Constituents

All Phenylpropanoids

84 total Filter phenylpropanoids

1,5-di-O-caffeoylquinic acid 1 herb 10-Gingerol 1 herb 2-Phenylethanol 1 herb 4-Hydroxycinnamoyl-quinic acid 1 herb 5-O-caffeoylquinic acid 1 herb 5-O-Caffeoylshikimic acid 1 herb 6-Gingerol 1 herb 6-Paradol 1 herb 6-Shogaol 1 herb 8-Gingerol 1 herb

Acetyleugenol 1 herb Alpha-asarone 1 herb Anethole 3 herbs Arenarioside 1 herb

Ballotetroside 1 herb Benzyl acetate 2 herbs Benzyl alcohol 2 herbs Benzyl benzoate 2 herbs Beta-asarone 1 herb Betonyoside A 1 herb

Caffeol 1 herb Capsaicin 1 herb Carvacrol 5 herbs Cinnamaldehyde 2 herbs

Open in filterable index

Source Plants

Herbs Containing Phenylpropanoids

57 herbs

Plants in the materia medica documented to carry phenylpropanoids, with the compounds each one is listed for. The bar counts how many DISTINCT phenylpropanoids 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.