Tutin - sweet poison – University of Copenhagen

01 October 2018

Tutin - sweet poison

Sherlock Holmes: There is a toxin, refined from the nectar of the Rhododendron ponticum. It’s quite infamous in the region of Turkey bordering the Black Sea for its ability to induce an apparently mortal paralysis. Enough to deceive even a medical mind as tenacious and wellrained as yours. It’s known locally as…

Mary Morstan: What’s wrong with Gladstone?

Sherlock Holmes: …mad honey disease.

Tutin is a neurotoxin found in the tutu plants (Coriaria spp.), native to New Zealand.  Intoxication could happen via consumption of tutu barriers or contaminated honey. And the way tutin ends up in honey is far stranger than one might expect. It took significant scientific detective work to determine this link. Bees (Apis mellifera) collect honeydew, which in turn is excreted by passionvine hoppers (Scolypopa australis) feeding on sap of the poisonous tutu. This was an unexpected discovery, as bees generally were not known to collect excretions of other insects.

Tutin was also identified in Asia and South America in Coriaria nepalensis, Coriaria japonica, and Coriaria ruscifolia plants.

Structure of tutin. Click figure for interactive 3D image

Symptoms of tutin intoxication are nausea, headache, vomiting and dizziness, in severe cases followed by seizures and coma. In case of poisoning by honey containing tutin, there is a great variability in time when symptoms first appear. In March 2008, 20 poisonings were reported (11 confirmed, 9 suspected).  The onset of the first clinical sign ranged between 0.5 and 17 hours. Subsequent study demonstrated two separate peaks of tutin in blood of 6 subjects, who consumed contaminated honey. The latest peak was suggested as tutin released in a delayed manner as its conjugates were metabolized. Varios tutin conjugates are been studied in order to monitor typical tutin concentration in contaminated honey and establishment of its safe limits.

SMILES: CC(=C)[C@@H]1[C@@H]2[C@H]([C@]3([C@@]4(CO4)[C@H]5[C@@H]([C@]3([C@H]1C(=O)O2)O)O5)C)O

References

  1. Chancellor AM. A bitter-sweet tale from the land of milk and honey. 2013;185–7.
  2. Larsen L, Joyce NI, Sansom CE, Cooney JM, Jensen DJ, Perry NB. Sweet Poisons: Honeys Contaminated with Glycosides of the Neurotoxin Tutin. 2015;
  3. Watkins OC, Joyce NI, Gould N, Perry NB. Glycosides of the Neurotoxin Tutin in Toxic Honeys Are from Coriaria arborea Phloem Sap, Not Insect Metabolism. 2018;
  4. Fields BA, Reeve J, Bartholomaeus A, Mueller U. Human pharmacokinetic study of tutin in honey ; a plant-derived neurotoxin. FOOD Chem Toxicol [Internet]. 2014;72:234–41. Available from: http://dx.doi.org/10.1016/j.fct.2014.07.032

Figures:
https://www.southernalpsphotography.com/Plants/New-Zealand-Flora/Trees/Tutu/i-4zcqBrT