Solanine

from Wikipedia, the free encyclopedia
Structural formula
Structure of solanine
General
Surname Solanine
other names

Solanid-5-en-3 β -yl- O -α- L -rhamnopyranosyl- (1 → 2) - O -β- D -glucopyranosyl- (1 → 3) -β- D -galactopyranoside

Molecular formula C 45 H 73 NO 15
Brief description

colorless and odorless solid

External identifiers / databases
CAS number 20562-02-1
EC number 243-879-8
ECHA InfoCard 100,039,875
PubChem 6537493
ChemSpider 28033
Wikidata Q373791
properties
Molar mass 868.06 g mol −1
Physical state

firmly

Melting point

285 ° C

solubility

almost insoluble in water (1.38 mg l −1 at 25 ° C)

safety instructions
GHS labeling of hazardous substances
07 - Warning

Caution

H and P phrases H: 302
P: no P-phrases
Toxicological data
As far as possible and customary, SI units are used. Unless otherwise noted, the data given apply to standard conditions .

Solanine , more precisely α-solanine, is a weakly poisonous chemical compound that is mainly found in nightshade plants such as potatoes and tomatoes . Chemically solanine is the saponin of the steroidal alkaloid solanidine with the trisaccharide Solatriose consisting of glucose , galactose and rhamnose exists. Solanine was first isolated in 1820 by the French pharmacist Desfosses from the berries of the black nightshade ( Solanum nigrum ), after which it was named. It is also incorrectly referred to as " tomatin ".

Occurrence

Solanine is mainly found in the nightshade family ( Solanaceae ) - such as potatoes.

The green part of potatoes contains a lot of solanine.

New potatoes achieve the highest values. If potatoes are exposed to light for a long time, the solanine content increases, especially in the shoots. The content also rises slightly in peeled, raw or mechanically damaged potatoes (bruises, frost damage), because more solanine is produced to combat putrefactive agents . Furthermore, the storage temperature and duration of storage have an influence on the increase in the alkaloid content. The ideal storage temperature for potatoes is 10 ° C.

The solanine content of potatoes used to be much higher than it is today. In a study from May 1943, the solanine content (total content) of potatoes of the Voran variety was given as 32.5 mg / 100 g, with small green potatoes reaching up to 55.7 mg / 100 g. In contrast, the content could only be increased insignificantly by very strong exposure and greening. Newer mainly cultivated potato varieties have a total glycoalkaloid content of 3 to 7 mg / 100 g (2013) or 2 to 10 mg / 100 g (WHO 1994 and 1996).

The Federal Institute for Risk Assessment recommended in 2018 a reduction in the hitherto regarded as harmless content of at most 20 mg / 100 g to 10 mg / 100 g of raw product. Reference was made to a poisoning case from 2015 that occurred after eating potatoes with a glycoalkaloid content of 23.6 mg / 100 g.

effect

It is currently believed that solanine causes depolarization of the mitochondrial membranes . The calcium content of the cytoplasm also increases . At least some of the calcium comes from the damaged mitochondria, since the calcium concentration in intact mitochondria is much higher than in the cytoplasm. The increase in the calcium concentration in the cytoplasm initiates cell death through apoptosis .

Solanine poisoning

Solanine poisoning used to be very common, especially in the form of a "heavy stomach" and nausea, and deaths have also been described. Today it has practically disappeared due to the low concentrations in modern farmed vegetables. The first symptoms of poisoning of the alkaloid such as drowsiness, hypersensitivity to touch ( hyperesthesia ) and difficulty breathing ( dyspnea ) occur in adults after ingesting approx. 200 mg . With continued solanine intake, nausea and vomiting occur; these symptoms are also described as solanism . Other symptoms are burning and scratching in the throat, stomach problems, intestinal inflammation, kidney inflammation with bloody urine, pain in the limbs, fever, kidney irritation, diarrhea and, in severe cases, even the dissolution of red blood cells, cardiac arrhythmias, circulatory and respiratory disorders and damage to the central nervous system ( Cramps, paralysis). A dose of 400 mg is considered fatal.

Solanine does not break down when it is cooked, but is partially transferred into the water used to cook solanine-containing fruits, as it is water-soluble at high temperatures. Therefore, the cooking water should not be used afterwards. Since solanine is heat-resistant and insoluble in fat , it is also not destroyed during deep-frying or frying. The solanine content of potatoes can be reduced by cutting off green spots and sprouts. Since the green color comes from chlorophyll and its formation only takes place after the biosynthesis of solanine, uncoloured potatoes can also have an increased solanine concentration.

toxicity

The average dose of 200 mg, at which the first symptoms of intoxication can appear, corresponds to the consumption of more than 2.8 kilograms of raw and unpeeled potatoes of new varieties with 7 mg solanine / 100 g. 30-80% of the solanine is in or directly below the shell. The dose depends on the body mass and varies greatly from person to person. The WHO gives doses of 3 to 6 mg glycoalkaloids per kg body weight as a lethal dose for humans. Doses of over 1 to 3 mg per kg of body weight are considered toxic.

The preparation reduces the solanine content by usually peeling and cleaning the potatoes. A part goes into the cooking water. Potato varieties currently available on the market do not cause any health risks under these conditions. However, this does not necessarily apply to older varieties. According to, green potatoes, some of which are on the surface, or certain types of potatoes can have inadmissibly high levels of 20 to 40 mg / 100 g.

The limit value of 10 mg / 100 g raw potatoes recommended by the Federal Institute for Risk Assessment in 2018 was justified by the fact that a NOAEL for the sum of glycoalkaloids of 0.5 mg / kg body weight and day should not be exceeded. Solanine makes up about 50% of the glycoalkaloid content of potatoes.

The maximum glycoalkaloid concentration in the blood serum was determined to be 4 to 8 hours after the consumption of potatoes with 20 mg / 100 g glycoalkaloids. The half-life of degradation in the body was on average 21 hours. Because of the slow degradation, a possible accumulation with daily intake is mentioned.

The aglycon solanidine is the main metabolite of the potato glycoalkaloids. It is accumulated in the liver and has a long retention time in the body. In 1992 it was found that the serum value, which had risen after 4 hours, did not fall again even after 25 hours (cited in).

Web links

Individual evidence

  1. ↑ Data solanine (PDF) at Carl Roth , accessed on 14 December of 2010.
  2. ↑ a b Entry on solanine in the ChemIDplus database of the United States National Library of Medicine (NLM) .
  3. ↑ a b Data sheet α-Solanine from Sigma-Aldrich , accessed on November 3, 2016 ( PDF ).
  4. ↑ a b c d e J. R. Whitaker, RE Feeney: Toxicants occurring naturally in foods . Ed .: National Research Council (US). Food Protection Committee. National Academy of Sciences, 1973, ISBN 0-309-02117-0 , Enzyme inhibitors in foods, pp. 276-298 (English).
  5. ↑ 764. Solanine and chaconine (WHO Food Additives Series 30). In: inchem.org. Retrieved May 8, 2020 .
  6. ↑ M. Desfosses: Extrait d'une lettre à M. Robiquet . In: Journal de Pharmacie . tape 6 , 1820, pp. 374-37 (French).
  7. ↑ SS Ahmed, K. Müller: Influence of storage time, light and temperature on the solanine and α-chaconin content of potatoes treated with and without sprout inhibitors . In: Potato Research . tape 24 , no. 1 , 1981, p. 93-99 , doi : 10.1007 / BF02362020 .
  8. ^ W. Lepper: Contribution to the solan inquiry. Exposure and solanine content of the potatoes . In: Journal for Food Inspection and Research, A. Volume 86 , no. 3-4 , 1943, pp. 247-250 , doi : 10.1007 / BF01662686 .
  9. ↑ a b W. Schuphan: Humans and food plants: The biological value of food plants in relation to pesticide use, soil quality and fertilization , Springer-Verlag 2013, 171 pages, page 43
  10. ↑ a b c d e f Federal Institute for Risk Assessment : Table potatoes should contain low levels of glycoalkaloids (solanine) , Opinion No. 010/2018 of April 23, 2018
  11. ^ Franzke C: General textbook of food chemistry , 3rd edition, Hamburg 1996, p. 257f, p. 244
  12. ↑ SY Gao, QJ Wang, YB Ji: Effect of solanine on the membrane potential of mitochondria in HepG2 cells and (Ca2 +) i in the cells . In: World Journal of Gastroenterology . tape 12 , no. June 21 , 2006, p. 3359-3367 , PMID 16733852 (English, wjgnet.com [accessed May 31, 2009]).
  13. ↑ Ursula Preiß, Bavarian State Office for Health and Food Safety, July 9, 2004 (Bavarian State Ministry for Environment, Health and Consumer Protection 2004); Consumer advice center Baden-Württemberg e. V. August 4, 1992, in: Green tomatoes and sprouted potatoes - The natural poison solanine , accessed on April 21, 2015
  14. ↑ Günter Vollmer , Gunter Josst, Dieter Schenker, Wolfgang Sturm, Norbert Vreden: Food guide : Contents, additives, residues: Part 2: Meat, fish, milk, fat, spices, beverages, food for diet, for babies, for athletes , volume 1, Science for Everyday Life, Verlag John Wiley & Sons, 2009, ISBN 3-527-62589-5 , p. 141.
  15. ↑ Dangerous peel - What makes the potato poisonous ( Memento of the original from January 13, 2014 in the Internet Archive ) Info: The archive link was inserted automatically and has not yet been checked. Please check the original and archive link according to the instructions and then remove this notice. , stern TV, November 14, 2007. @1@ 2Template: Webachiv / IABot / www.stern.de
  16. ↑ Michael Murkovic, Toxins in Plant Food , Graz University of Technology, Institute for Food Chemistry and Technology, p. 6.
  17. ^ Executive Summary of Chaconine & Solanine ( Memento from August 15, 2006 in the Internet Archive ).
  18. ↑ Bavarian State Ministry for the Environment, Health and Consumer Protection: Solanine (glycoalkaloids) in potatoes .
  19. ↑ Hellenas, KE; Nyman, A .; Slanina, P .; Loof, L .; Gabrielsson, J .: Determination of potato glycoalkaloids and their aglycone in blood serum by high-performance liquid chromatography. Application to pharmacokinetic studies in humans , in Journal of Chromatography 573, pages 69-78.