Guaianolide

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Chemical structures of the two forms of guaianolide nucleus, 6,12-guaianolides (left) and 8,12-guaianolides (right) Guaianolide core structures.svg
Chemical structures of the two forms of guaianolide nucleus, 6,12-guaianolides (left) and 8,12-guaianolides (right)

In organic chemistry, a guaianolide is a type of sesquiterpene lactone consisting of a gamma-lactone and either a cyclopentane or cyclopentene, both fused to a central cycloheptane or cycloheptene structure. There are two subclasses, structural isomers differing in the location that part of the lactone is bonded to the central ring, known as 6,12-guaianolides and 8,12-guaianolides. [1]

Because some of the natural products in this class of tricyclic phytochemical have been found to be potentially biologically active, there has been interest in their chemical syntheses. [2] The full biosynthetic origin of most of the known guaianolides has not been established, but the pathway is generally presumed to begin with the formation of a germacrene lactone derived from farnesyl pyrophosphate. [1]

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Bilobalide

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<i>Calea ternifolia</i> Species of plant

Calea ternifolia is a species of flowering plant in the aster family, Asteraceae. It is native to Mexico and Central America. Its English language common names include bitter-grass, Mexican calea, and dream herb.

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<i>Crepis</i> Genus of flowering plants in the daisy family Asteraceae

Crepis, commonly known in some parts of the world as hawksbeard or hawk's-beard, is a genus of annual and perennial flowering plants of the family Asteraceae superficially resembling the dandelion, the most conspicuous difference being that Crepis usually has branching scapes with multiple heads. The genus name Crepis derives from the Greek krepis, meaning "slipper" or "sandal", possibly in reference to the shape of the fruit.

Lactucin Chemical compound

Lactucin is a bitter substance that forms a white crystalline solid and belongs to the group of sesquiterpene lactones. It is found in some varieties of lettuce and is an ingredient of lactucarium. It has been shown to have analgesic and sedative properties. It has also shown some antimalarial effects. It is also found in dandelion coffee.

Lactucopicrin Chemical compound

Lactucopicrin (Intybin) is a bitter substance that has a sedative and analgesic effect, acting on the central nervous system. It is a sesquiterpene lactone, and is a component of lactucarium, derived from the plant Lactuca virosa, as well as being found in some related plants such as Cichorium intybus. It is also found in dandelion coffee.

Parthenolide Chemical compound

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Sesquiterpene

Sesquiterpenes are a class of terpenes that consist of three isoprene units and often have the molecular formula C15H24. Like monoterpenes, sesquiterpenes may be acyclic or contain rings, including many unique combinations. Biochemical modifications such as oxidation or rearrangement produce the related sesquiterpenoids.

Helenalin Chemical compound

Helenalin, or (-)-4-Hydroxy-4a,8-dimethyl-3,3a,4a,7a,8,9,9a-octahydroazuleno[6,5-b]furan-2,5-dione, is a toxic sesquiterpene lactone which can be found in several plants such as Arnica montana and Arnica chamissonis subsp. foliosa. Helenalin is responsible for the toxicity of the Arnica spp. Although toxic, helenalin possesses some in vitro anti-inflammatory and anti-neoplastic effects. Helenalin can inhibit certain enzymes, such as 5-lipoxygenase and leukotriene C4 synthase. For this reason the compound or its derivatives may have potential medical applications.

Sclareolide Chemical compound

Sclareolide is a sesquiterpene lactone natural product derived from various plant sources including Salvia sclarea, Salvia yosgadensis, and cigar tobacco. It is a close analog of sclareol, a plant antifungal compound.

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Russula brevipes is a species of mushroom commonly known as the short-stemmed russula or the stubby brittlegill. It is widespread in North America, and was reported from Pakistan in 2006. The fungus grows in a mycorrhizal association with trees from several genera, including fir, spruce, Douglas-fir, and hemlock. Fruit bodies are white and large, with convex to funnel-shaped caps measuring 7–30 cm (3–12 in) wide set atop a thick stipe up to 8 cm (3 in) long. The gills on the cap underside are closely spaced and sometimes have a faint bluish tint. Spores are roughly spherical, and have a network-like surface dotted with warts.

<i>Eupatorium rotundifolium</i> Species of flowering plant

Eupatorium rotundifolium, commonly called roundleaf thoroughwort, is a North American species of plant in sunflower family. It native to the eastern and central United States, in all the coastal states from Maine to Texas, and inland as far as Missouri and the Ohio Valley. It is found in low, moist habitats such as wet savannas and bogs.

Dandelion coffee

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Absinthin Chemical compound

Absinthin is a naturally produced triterpene lactone from the plant Artemisia absinthium (Wormwood). It constitutes one of the most bitter chemical agents responsible for absinthe's distinct taste. The compound shows biological activity and has shown promise as an anti-inflammatory agent, and should not to be confused with thujone, a neurotoxin also found in Artemisia absinthium.

Merrilactone A Chemical compound

Merrilactone A is one of the four sesquiterpenes that were newly discovered from the fruit of Illicium merrillianum in 2000. Members of the genus Illicium include Chinese star anise, widely used as a spice for flavouring food and beverages, and also poisonous plants such as Japanese star anise. Chemical studies of Illicium have developed rapidly over the last 20 years, and merrilactone A has been shown to have neurotrophic activity in fetal rat cortical neuron cultures. This has led researchers to believe that Merrilactone A may hold therapeutic potential in the treatment of neuro-degenerative diseases such as Alzheimer's disease and Parkinson's disease.

Costunolide Chemical compound

(+)-Costunolide is a naturally occurring sesquiterpene lactone, first isolated in Saussurea costus roots in 1960. It is also found in lettuce.

Cynaropicrin is a sesquiterpene lactone of the guaianolide type found mainly in leaves of artichoke plants. It is one of the compounds that gives the artichoke its characteristic bitterness. It is found in artichoke leaves with an abundance of approximately 87 g/kg, but can hardly be found in other parts of the plant. Cynaropicrin makes up about 0.7% of leaf extracts of the artichoke. It exhibits a large diversity of bioactivities and shows properties such as anti-inflammatory, antifeedant and activation of bitter sensory receptors, but has not yet been used in medicine. Despite its pharmacologically beneficial properties, it can be toxic in higher doses. The compound has attracted attention in recent years as a potential anticancer drug.

Arglabin Chemical compound

Arglabin is a sesquiterpene lactone belonging to the guaianolide subclass bearing a 5,7,5-tricyclic ring system which is known to inhibit farnesyl transferase. It is characterized by an epoxide on the cycloheptane as well as an exocyclic methylene group that is conjugated with the carbonyl of the lactone. Arglabin is extracted from Artemisia glabella, a species of wormwood, found in the Karaganda Region of Kazakhstan. Arglabin and its derivatives are biologically active and demonstrate promising antitumor activity and cytoxocity against varying tumor cell lines.

References

  1. 1 2 Henrik Toft Simonsen, Corinna Weitzel and Søren Brøgger Christensen (2013). K. G. Ramawat, J. M. Merillon (ed.). "Guaianolide Sesquiterpenoids: Pharmacology and Biosynthesis". Natural Products: 3069–3098. doi:10.1007/978-3-642-22144-6_134. ISBN   978-3-642-22143-9.
  2. Hu, Xirui; Musacchio, Andrew J.; Shen, Xingyu; Tao, Yujia; Maimone, Thomas J. (2019). "Allylative Approaches to the Synthesis of Complex Guaianolide Sesquiterpenes from Apiaceae and Asteraceae". J. Am. Chem. Soc. 141 (37): 14904–14915. doi:10.1021/jacs.9b08001. PMC   6818654 . PMID   31448610.