Gluconasturtiin
Gluconasturtiin or phenethyl glucosinolate is one of the most widely distributed glucosinolates in the cruciferous vegetables, mainly in the roots, and is probably one of the plant compounds responsible for the natural pest-inhibiting properties of growing crucifers, such as cabbage, mustard or rape, in rotation with other crops. This effect of gluconasturtiin is due to its degradation by the plant enzyme myrosinase into phenethyl isothiocyanate, which is toxic to many organisms.[1]
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| Names | |
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| IUPAC name
1-S-[(1Z)-3-Phenyl-N-(sulfooxy)propanimidoyl]-1-thio-β-D-glucopyranose | |
| Other names
Phenethyl glucosinolate | |
| Identifiers | |
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| ChEBI | |
| ChemSpider | |
| ECHA InfoCard | 100.231.959 |
PubChem CID |
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CompTox Dashboard (EPA) |
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| Properties | |
| C15H21NO9S2 | |
| Molar mass | 423.45 g·mol−1 |
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
Infobox references | |
Gluconasturtiin is named from its occurrence in watercress (Nasturtium officinale). Among the vegetables, it is also found in horseradish (Armoracia rusticana) along with sinigrin. Both compounds elicit a pungent taste.[2]
Occurrence
The compound was first reported in 1899, after its isolation from watercress, Nasturtium officinale, and the cress Barbarea verna.[1]: Section 2 Gluconasturtiin is now known to occur widely in other brassica families including Brassicaceae and Resedaceae.[3]
In one investigation of horseradish roots, sinigrin represented 83% and gluconasturtiin 11% of the extracted glucosinolates.[4]
Synthesis
Biosynthesis
Gluconasturtiin is biosynthesised from the amino acid phenylalanine in a multi-step pathway.[1]
Laboratory synthesis
The first laboratory synthesis served to confirm the compound's structure.[5] Later work allowed many glucosinolates including this phenethyl derivative to be made. These processes are more efficient than isolating pure materials from the plants in which they are naturally found.[1]: Section 3
Function
The natural role of glucosinolates are as plant defense compounds. The enzyme myrosinase removes the glucose group in gluconasturiin to give an intermediate which spontaneously rearranges to phenethyl isothiocyanate. This is a reactive material which is toxic to many insect predators and its production is triggered when the plant is damaged.[6] This effect has been called the mustard oil bomb.[7] At concentrations typically found in foods, the glucosinolates are not toxic to humans and can be useful flavor components.[8]
References
- Blažević, Ivica; Montaut, Sabine; Burčul, Franko; Olsen, Carl Erik; Burow, Meike; Rollin, Patrick; Agerbirk, Niels (2020). "Glucosinolate structural diversity, identification, chemical synthesis and metabolism in plants". Phytochemistry. 169: 112100. doi:10.1016/j.phytochem.2019.112100. PMID 31771793. S2CID 208318505.
- (in French) RICHARD H. Arômes alimentaires PDF Document Archived February 14, 2007, at the Wayback Machine
- Fahey, Jed W.; Zalcmann, Amy T.; Talalay, Paul (2001). "The chemical diversity and distribution of glucosinolates and isothiocyanates among plants". Phytochemistry. 56 (1): 5–51. doi:10.1016/S0031-9422(00)00316-2. PMID 11198818.
- Li, Xian; Kushad, Mosbah M. (2004). "Correlation of Glucosinolate Content to Myrosinase Activity in Horseradish (Armoracia rusticana)". Journal of Agricultural and Food Chemistry. 52 (23): 6950–6955. doi:10.1021/jf0401827. PMID 15537302.
- Benn, M. H. (1964). "The Synthesis of Gluconasturiin". Journal of the Chemical Society (Resumed): 4072–3. doi:10.1039/JR9640004053.
- Morant, Anne Vinther; Jørgensen, Kirsten; Jørgensen, Charlotte; Paquette, Suzanne Michelle; Sánchez-Pérez, Raquel; Møller, Birger Lindberg; Bak, Søren (2008). "β-Glucosidases as detonators of plant chemical defense". Phytochemistry. 69 (9): 1795–1813. doi:10.1016/j.phytochem.2008.03.006. PMID 18472115.
- Matile, Ph. (1980). ""Die Senfolbombe": Zur Kompartimentierung des Myrosinasesystems". Biochemie und Physiologie der Pflanzen (in German). 175 (8–9): 722–731. doi:10.1016/S0015-3796(80)80059-X.
- Fenwick, G. Roger; Heaney, Robert K.; Mullin, W. John; Vanetten, Cecil H. (1983). "Glucosinolates and their breakdown products in food and food plants". C R C Critical Reviews in Food Science and Nutrition. 18 (2): 123–201. doi:10.1080/10408398209527361. PMID 6337782.