Antifeedant

Amygdalin, a cyanide-releasing compound, is produced by some plants to deter herbivores.

Antifeedants are organic compounds produced by plants to repel herbivores through distaste or toxicity. These chemical compounds are typically classified as secondary metabolites in that they are not essential for the metabolism of the plant, but instead confer longevity. Antifeedants exhibit a wide range of activities and chemical structures as biopesticides. Examples include rosin, which inhibits attack on trees, and many alkaloids, which are highly toxic to specific insect species, ^[2] such as quassinoids (extracts from Quassia trees) against the diamondback moth ( Plutela xylostella ). ^[3] Samadera indica also has quassinoids used for insect antifeedant uses. ^[4]

Limonoids such as limonin are antifeedants produced by a number of plants of the families Cucurbitaceae Rutaceae and Meliaceae.

History

"Plant-derived insecticides (e.g., rotenone, veratridines, pyrethrins, and nicotine) have been used for insect control since antiquity." ^[6] The active ingredients in these plants have been purified and modified. For example, variations on pyrethrin have spawned a large number of synthetic insecticides called pyrethroids.

Culinary implications

In addition to their role defending the plant, antifeedants often confer taste or odors, enhancing the flavor of certain plants. Examples are provided by cruciferous vegetables including mustard, cabbage, and horseradish, which release pungent oils containing glucosinolates when the plant material is chewed, cut, or otherwise damaged. ^[7] The odorous components of garlic are thought to have evolved to deter insects. ^[8]

• Common plants known as sources of antifeedants
• 
  Green garlic, which releases alliin upon cutting
• 
  Tobacco plants, which produce nicotine
• 
  Chrysanthemum flowers, which contain pyrethrin
• 
  horseradish plants, which release allyl isothiocyanate upon cutting

References

1. Gleadow, RM; Møller, BL (2014). "Cyanogenic glycosides: synthesis, physiology, and phenotypic plasticity". Annual Review of Plant Biology. 65: 155–85. doi:10.1146/annurev-arplant-050213-040027. PMID   24579992.
2. Richard N. Bennett; Roger M. Wallsgrove (1994). "Secondary metabolites in plant defence mechanisms". New Phytologist. 127 (4): 617–633. doi:10.1111/j.1469-8137.1994.tb02968.x. PMID   33874382.
3. Daido, M.; Ohno, N.; Imamura, K.; Fukamiya, N.; Hatakoshi, M.; Yamazaki, H.; et al. (1995). "Antifeedant and insecticidal activity of quassinoids against the diamondback moth (Plutela xylostella) and structure-activity relationships". Biosci. Biotechnol. Biochem. 59 (6): 974–9. doi:10.1271/bbb.59.974.
4. Govindachari, T.R.; Krishnakumari, G.N.; Gopalakrishnan, G.; Suresh, G.; Wesley, S.D.; Sreelatha, T. (2001). "Insect antifeedant and growth regulating activities of quassinoids from Samadera indica". Fitoterapia. 72 (5): 568–71. doi:10.1016/S0367-326X(00)00342-7. PMID   11429258.
5. Amit Roy and Shailendra Saraf (2006). "Limonoids: Overview of Significant Bioactive Triterpenes Distributed in Plants Kingdom". Biol. Pharm. Bull. 29 (2): 191–201. doi: 10.1248/bpb.29.191 . PMID   16462017.
6. Metcalf, Robert L. (2000). "Insect Control". Ullmann's Encyclopedia of Industrial Chemistry. doi:10.1002/14356007.a14_263. ISBN   978-3-527-30673-2.
7. Johnson, I. T (2002). "Glucosinolates: Bioavailability and importance to health". International Journal for Vitamin and Nutrition Research. 72 (1): 26–31. doi:10.1024/0300-9831.72.1.26. PMID   11887749.
8. Macpherson, Lindsey J.; Geierstanger, Bernhard H.; Viswanath, Veena; Bandell, Michael; Eid, Samer R.; Hwang, SunWook; Patapoutian, Ardem (May 24, 2005). "The Pungency of Garlic: Activation of TRPA1 and TRPV1 in Response to Allicin" (PDF). Current Biology . 15 (10): 929–34. Bibcode:2005CBio...15..929M. doi: 10.1016/j.cub.2005.04.018 . PMID   15916949.