Sesquiterpene lactone explained

Sesquiterpene lactones (SLs) are a class of sesquiterpenoids that contain a lactone ring. They are most often found in plants of the family Asteraceae (daisies, asters). Other plant families with SLs are Umbelliferae (celery, parsley, carrots) and Magnoliaceae (magnolias). A collection of colorless, lipophilic solids, SLs are a rich source of drugs.^[1] They can be allergenic and toxic in grazing livestock^[2] causing severe neurological problems in horses. Some are also found in corals of the order Alcyonacea.

Types

Sesquiterpene lactones can be divided into several main classes including germacranolides, heliangolides, guaianolides, pseudoguaianolides, hypocretenolides, and eudesmanolides.

Examples

Artemisinin, a new, highly-effective anti-malarial compound, is a sesquiterpene lactone found in Artemisia annua. Lactucin, desoxylactucin, lactucopicrin, lactucin-15-oxalate, lactucopicrin-15-oxalate are some of the most prominent found in lettuce and spinach, giving most of the bitter taste to these crops.

One eudesmanolide, 3-oxo-5αH,8βH-eudesma-1,4(15),7(11)-trien-8,12-olide, can work with vernolic acid and other compounds in plants to reduce inflammation.^[3]

Sesquiterpene lactone-containing plants

Some plants containing these compounds include:

• Artichoke
• Eupatorium^[4]
• Burdock
• Calea ternifolia
• Chamomile
• Chrysanthemum
• Cockleburs
• Feverfew
• Gaillardia
• Ginkgo biloba
• Laurus nobilis^[5]
• Lettuce (Lactuca)
• Mugwort
• Parthenium
• Iva (marsh elders)
• Pyrethrum
• Ragweed
• Sagebrush
• Spinach
• Star anise
• Sunflower
• Vernonia^[6]
• Wormwood
• Yellow star thistle

Quorum sensing inhibitors

Sesquiterpene lactones have been found to possess the ability to inhibit quorum sensing in bacteria.^[7]

Notes and References

1. What Made Sesquiterpene Lactones Reach Cancer Clinical Trials?. Ghantous, Akram . Gali-Muhtasib, Hala . Vuorela, Heikki . Saliba, Najat A. . Darwiche, Nadine. Drug Discovery Today. 2010. 15. 15–16. 668–678. 10.1016/0305-1978(86)90101-8. 20541036.
2. Web site: Sesquiterpene Lactones and their toxicity to livestock . . Cornell CALS. Cornell University . December 29, 2018 .
3. Nakagawa M, Ohno T, Maruyama R, Okubo M, Nagatsu A, Inoue M, Tanabe H, Takemura G, Minatoguchi S, Fujiwara H . Sesquiterpene lactone suppresses vascular smooth muscle cell proliferation and migration via inhibition of cell cycle progression . Biol. Pharm. Bull. . 30 . 9 . 1754–7 . September 2007 . 17827734 . 10.1248/bpb.30.1754 . free . 20.500.12099/23170 . free .
4. Herz W, Kalyanaraman PS, Ramakrishnan G . Sesquiterpene lactones of Eupatorium perfoliatum . J. Org. Chem. . 42 . 13 . 2264–71 . June 1977 . 874606 . 10.1021/jo00433a017 .
5. Dall'Acqua S, Viola G, Giorgetti M, Loi MC, Innocenti G . Two new sesquiterpene lactones from the leaves of Laurus nobilis . Chem. Pharm. Bull. . 54 . 8 . 1187–9 . August 2006 . 16880666 . 10.1248/cpb.54.1187 . free .
6. Book: Crellin JK, Philpott J, Tommie Bass AL. Herbal Medicine Past and Present: A reference guide to medicinal plants. 1990. Duke University Press. 0-8223-1019-8. 265–.
7. Amaya S, Pereira JA, Borkosky SA, Valdez JC, Bardón A, Arena ME . Inhibition of quorum sensing in Pseudomonas aeruginosa by sesquiterpene lactones . Phytomedicine . 19 . 13 . 1173–7 . October 2012 . 22925726 . 10.1016/j.phymed.2012.07.003 . 11336/77653 . free .