Category: Natural chemicals
Introduction and description
Hordenine (N,N-dimethyl-4-hydroxyphenylethylamine) is a phenethylamine alkaloid. It occurs naturally in grains, sprouting barley, and certain grasses. It can also be found in a number of cactii [often called false peyote].
There is an entry for Hordenine in the overload section under Medicines, as it is being sold as a supplement and causing some fairly extraordinary hallucinations [also shown below]. But there is value in also recording its existence here as it may have some uses which are, shall we say, a little more positive.
In general, Hordenine is found in sprouting seeds such as those of barley, or in slow growing cactus.
It is classified as an antifeedant. An Antifeedant is "a naturally occurring substance in certain plants which adversely affects insects or other animals which eat them".[OED]
In other words, Hordenine is used by the plant to protect itself. Sprouting seeds are tasty and they can be nutritious, but if an animal comes along and eats them, the plant has basically lost its babies! So the plant in this case is protecting its young.
Slow growing cactus are at very great risk from predators. Most other plants in favourable conditions can grow back any part of the plant eaten by a foraging animal, but a cactus might take years before it is able to grow back a part eaten by insects. The spines on a cactus deter the larger predator, but there is a still a problem from insects and thus many cactii use chemicals to deter insects.
We may find in time that it is a much more frequently used chemical in plants than we realise, it is just that we have not been looking. Dr Duke, for example, found Hordenine in the shoot of Pancratium maritimum L. – the Sea Daffodil; in Selenicereus grandiflorus (L.) – the Night-Blooming Cereus, Queen-of-the-Night; and in the bark [NOT fruit] of Tamarindus indica L. – the Indian Tamarind. It is also present in the Silk Stigma of sweet corn – the layer that protects the seeds. In each case this is consistent with its protective effects.
Hordenine is known to act as a feeding deterrent to grasshoppers (Melanoplus bivittatus), and to caterpillars of Heliothis virescens and Heliothis subflexa; the estimated concentration of hordenine that reduced feeding duration to 50% of control was 0.4M for H. virescens and 0.08M for H. subflexa.
In all cases it poisons them, thus we can think of Hordenine as an insecticide and pesticide.
The first report of the isolation of hordenine was made by Arthur Heffter in 1894, who extracted it from the cactus Anhalonium fissuratum (now reclassified as Ariocarpus fissuratum), naming it "anhalin".
The first pharmacological study of hordenine to be recorded is also that of Heffter. Using the sulfate salt, Heffter gave a subcutaneous dose of 0.3 g to a 2.8 kg cat (~ 107 mg/kg), and I quote “observed no effects besides violent vomiting; the cat behaved normally within 45 mins”. [Animals automatically vomit if they ingest anything poisonous].
He also took a dose of 100 mg orally himself, without experiencing any observable effect. Personally I think it might have been more ethical if he had done it the other way round, but there you go that’s scientists for you.
For reasons that one cannot even begin to imagine, Hordenine is, according to Wikipedia, “widely sold as an ingredient of nutritional supplements, with the claims that it is a stimulant of the central nervous system, and has the ability to promote weight loss by enhancing metabolism”.
When given to humans Hordenine poisons them too. So anyone selling Hordenine as anything - health food, weight loss aid, fitness aid etc - is actually selling you a poison, which in my book is attempted murder. One can compare this with giving someone a glass of DDT.
But plants containing Hordenine may be exceptionally useful as companion plants. In effect one may be able to deter some insects from eating more vulnerable plants by giving them a companion plant containing Hordenine.
Hordenine is found in nature in several varieties of plants in the family Cactaceae and by some in Acacia. The Peyote (Lophophora williamsii), San Pedro cactus (Echinopsis pachanoi), and Peruvian Torch cactus (Echinopsis peruviana) all produce high levels of this compound.
Sprouting barley (Hordeum vulgare) seeds contain hordenine as the main alkaloid in their roots. Barley itself does not contain hordenine - seeds or plant, only the sprouting seed:
Forty-three lines of barley, including ancestral (wild), landraces, Middle Eastern lines, and modern cultivars, were grown under two different sets of environmental conditions. Hordenine production in barley roots was determined at the one-leaf stage by HPLC analysis and, in two lines only, over a period of 35 days. Forty-two of the 43 lines produced significant amounts of hordenine, although there was no variation among groups. Middle Eastern lines had the highest production with 327 µg/g on a dry weight basis. Production was, however, determined more by environmental conditions during growth than by genetic factors. Hordenine production was up to seven times higher in plants grown under lower light intensities. PMID: 24242721
The alkaloid is also present in reed canarygrass (Phalaris arundinacea), a tall perennial grass, and in Ungernia trisphaera, a small flowering species.
The following list of plants derived from Christian Rasch’s Encyclopaedia of Psychoactive plants shows those which he believes contain Hordenine.
- Ariocarpus family of cactus including agavoides, fissuratus, kotschoubeyanus, retusus, schaphorostrus, trigonus
- Cannabis sativa – the leaves contain some hordenine
- Coryphantha – most species contain primarily hordenine [Howe et al 1977]
- Desmodium tiliaefolium
- Epithelantha micromeris
- Eriogonum spp – the desert trumpet
- Lobivia spp
- Lophophora Wlliamsii and diffusa – contain some hordenine although the primary alkaloid is mescaline
- Mamillaria – craigii, grahamii, herderi, longimamma and senilis
- Obregonia denegrii
- Pelecyphora – both aselliformis and pseudopectinata
- Polyporus berkeleyi
- Sceletium joubertii
- Solisia pectinata
- Trichocereus pachanoi and pasana
- Turbinicarpus - a genus of very small to medium-sized cacti e.g. pseudomacrochele, pseudopectinatus
- Galanthus elwesii and Galanthus nivalis - [ref Berkov S, Bastida J, Sidjimova B, Viladomat F, Codina C.; Chem Biodivers. 2011 PMID: 21259423]
- Senecio scandens - ref Tan D, Chen Y, Ji L, Chou G, Wang Z; Zhongguo Zhong Yao Za Zhi. 2010 Oct;35(19):2572-5. Chinese.; PMID: 21174767
References and further reading
K. L. S. Harley (1967). "The influence of plant chemicals on the feeding behavior, development, and survival of the two-striped grasshopper, Melanoplus bivittatus (Sap), Aeridae: Orthoptera." Can J. Zool. 45 305-319.
E. A. Bernays et al. (2000). "Taste sensitivity of insect herbivores to deterrents is greater in specialists than in generalists: a behavioral test of the hypothesis with two closely related caterpillars." J. Chem. Ecol.26 547-563.