Constipatic acid is a

fatty acid In chemistry, particularly in biochemistry, a fatty acid is a carboxylic acid with an aliphatic chain, which is either saturated or unsaturated. Most naturally occurring fatty acids have an unbranched chain of an even number of carbon atoms, ...

found in several lichen species. It was isolated, identified, and named by Douglas Chester and

John Alan Elix John Alan (Jack) Elix (born 1941) emeritus professor in chemistry at the Australian National University, is an organic chemist who has contributed in many fields: lichenology, lichen chemotaxonomy, plant physiology and biodiversity and natural p ...

in a 1979 publication. The compound was

extracted ''Extracted'', also known as ''Extraction'' in the UK, is an independent 2012 American science fiction thriller directed and written by Nir Paniry. Sasha Roiz stars as a scientist whose consciousness becomes trapped in the mind of a convict (Domi ...

from the Australian leafy lichen called '' Xanthoparmelia constipata'' (after which the compound is named), which was collected on

schist Schist ( ) is a medium-grained metamorphic rock showing pronounced schistosity. This means that the rock is composed of mineral grains easily seen with a low-power hand lens, oriented in such a way that the rock is easily split into thin flakes ...

boulders west of Springton, South Australia. The related compounds protoconstipatic acid and dehydroconstipatic acid were also reported concurrently. Syo Kurokawa and Rex Filson had previously detected the compounds using

thin-layer chromatography Thin-layer chromatography (TLC) is a chromatography technique used to separate non-volatile mixtures. Thin-layer chromatography is performed on a sheet of an inert substrate such as glass, plastic, or aluminium foil, which is coated with a t ...

when they formally described the lichen as a new species in 1975, but had not characterised them chemically. After conversion of constipatic acid to methyl constipatate, a

mass spectra A mass spectrum is a histogram plot of intensity vs. ''mass-to-charge ratio'' (''m/z'') in a chemical sample, usually acquired using an instrument called a ''mass spectrometer''. Not all mass spectra of a given substance are the same; for example ...

of the compound revealed four diagnostic peaks at the

mass-to-charge ratio The mass-to-charge ratio (''m''/''Q'') is a physical quantity relating the ''mass'' (quantity of matter) and the ''electric charge'' of a given particle, expressed in units of kilograms per coulomb (kg/C). It is most widely used in the electro ...

(m/e) of 367, 338, 279 and 169. The peaks correspond to the cleavage of a

methyl group In organic chemistry, a methyl group is an alkyl derived from methane, containing one carbon atom bonded to three hydrogen atoms, having chemical formula . In formulas, the group is often abbreviated as Me. This hydrocarbon group occurs in ma ...

, the 1-hydroxyethyl moiety, the methoxycarbonyl group (i.e. CH₃-O-CO-) and 1-cleavage of the side chain. Additional analysis with

proton nuclear magnetic resonance Proton nuclear magnetic resonance (proton NMR, hydrogen-1 NMR, or 1H NMR) is the application of nuclear magnetic resonance in NMR spectroscopy with respect to hydrogen-1 nuclei within the molecules of a substance, in order to determine the struct ...

corroborated these results and confirmed the linear nature of the

aliphatic In organic chemistry, hydrocarbons ( compounds composed solely of carbon and hydrogen) are divided into two classes: aromatic compounds and aliphatic compounds (; G. ''aleiphar'', fat, oil). Aliphatic compounds can be saturated, like hexane, ...

chain. In addition to ''Xanthoparmelia constipata'', constipatic acid has been isolated from several other ''

Xanthoparmelia ''Xanthoparmelia'' (commonly known as green rock shields or rock-shield lichens) is a genus of foliose lichen in the family Parmeliaceae.Field Guide to California Lichens, Stephen Sharnoff, Yale University Press, 2014, ''Xanthoparmelia'' is sy ...

'' species, including '' X. perezdepazii'', '' X. filarskyana'', '' X. flavecentireagens'', '' X. lineola'', and '' X. metaclystoides''. It has been isolated from lichens in other genera as well. Examples include ''

Parmelia xanthosorediata Parmelia may refer to: * Parmelia (barque) ''Parmelia'' was a barque built in Quebec, Canada, in 1825. Originally registered on 31 May in Quebec, she sailed to Great Britain and assumed British registry. She made one voyage for the British East I ...

'', ''

Heterodermia appendiculata ''Heterodermia'' is a genus of lichenized fungi in the family Physciaceae. The genus has a widespread distribution, especially in tropical regions, and contains about 80 species. Description ''Heterodermia'' are subterranean or almost upright ...

'', ''

Heterodermia japonica ''Heterodermia'' is a genus of lichenized fungi in the family Physciaceae. The genus has a widespread distribution, especially in tropical regions, and contains about 80 species. Description ''Heterodermia'' are subterranean or almost upright le ...

'', ''

Protoparmelia nebulosa ''Protoparmelia'' is a genus of lichenized fungi in the family Parmeliaceae. The genus has a widespread distribution, and contains 11 species. ''Protoparmelia'' was circumscribed by French lichenologist Maurice Choisy in 1929. Species *'' Pro ...

'', ''

Hertelidea wankaensis ''Hertelidea wankaensis'' is a species of crustose lichen in the family Stereocaulaceae. It is found in northeastern Australia, where it grows on dead wood. Taxonomy The lichen was described as a new species in 2006 by lichenologists Gintar ...

'', ''

Lepraria coriensis ''Lepraria'' is a genus of leprose crustose lichens that grows on its substrate like patches of granular, caked up, mealy dust grains.A taxonomic revision of the North American species of Lepraria s.l. that produce divaricatic acid, with note ...

'', ''

Punctelia negata ''Punctelia negata'' is a little-known species of foliose lichen in the family Parmeliaceae. It is found in South America. Taxonomy The lichen was described as a new species by Finnish lichenologist William Nylander in 1872. Giving a brief di ...

'', and ''

Rhizoplaca melanophthalma ''Rhizoplaca'' is a genus of lichenized fungi in the family Lecanoraceae. Members of the genus are commonly called rimmed navel lichens because of their umbilicate growth form and lecanorine (rimmed with thallus Thallus (plural: thalli), f ...

''. Some sources consider the molecule to have an unusual or humorous name due to its similarity to the word "

constipation Constipation is a bowel dysfunction that makes bowel movements infrequent or hard to pass. The stool is often hard and dry. Other symptoms may include abdominal pain, bloating, and feeling as if one has not completely passed the bowel moveme ...

References

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Los Angeles Times The ''Los Angeles Times'' (abbreviated as ''LA Times'') is a daily newspaper that started publishing in Los Angeles in 1881. Based in the LA-adjacent suburb of El Segundo since 2018, it is the sixth-largest newspaper by circulation in the ...

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See also

References