Constipatic acid

Constipatic acid is a fatty acid found in several lichen species. It was isolated, identified, and named by Douglas Chester and John Alan Elix in a 1979 publication. The compound was extracted from the Australian leafy lichen called Xanthoparmelia constipata (after which the compound is named), which was collected on schist boulders west of Springton, South Australia. The related compounds protoconstipatic acid and dehydroconstipatic acid were also reported concurrently.^[1] Syo Kurokawa and Rex Filson had previously detected the compounds using thin-layer chromatography when they formally described the lichen as a new species in 1975, but had not characterised them chemically.^[2]

Constipatic acid

Names
IUPAC name 2-(14'-hydroxypentadecyl)-4-methyl-5-oxo-2,5-dihydrofuran-3-carboxylic acid
Other names neuropogolic acid
Identifiers
3D model (JSmol)	Interactive image
ChemSpider	8794415
PubChem CID	57459988
InChI InChI=1S/C21H36O5/c1-16(22)14-12-10-8-6-4-3-5-7-9-11-13-15-18-19(20(23)24)17(2)21(25)26-18/h16,18,22H,3-15H2,1-2H3,(H,23,24) Key: RJNPNSFGRBJXHX-UHFFFAOYSA-N
SMILES CC(O)CCCCCCCCCCCCCC1OC(=O)C(=C1C(O)=O)C
Properties
Chemical formula	C21H36O5
Molar mass	368.514 g·mol−1
Appearance	white flakes
Melting point	108–109°
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa). Infobox references

After conversion of constipatic acid to methyl constipatate, a mass spectra of the compound revealed four diagnostic peaks at the mass-to-charge ratio (m/e) of 367, 338, 279 and 169. The peaks correspond to the cleavage of a methyl group, 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 corroborated these results and confirmed the linear nature of the aliphatic chain.^[1]

In addition to Xanthoparmelia constipata, constipatic acid has been isolated from several other Xanthoparmelia species, including X. perezdepazii,^[3] X. filarskyana, X. flavecentireagens, X. lineola, and X. metaclystoides.^[4] It has been isolated from lichens in other genera as well. Examples include Parmelia xanthosorediata, Heterodermia appendiculata, Heterodermia japonica,^[5] Protoparmelia nebulosa,^[6] Hertelidea wankaensis,^[7] Lepraria coriensis,^[8] Punctelia negata,^[9] and Rhizoplaca melanophthalma.^[10]

Some sources consider the molecule to have an unusual or humorous name due to its similarity to the word "constipation".^[11][12]

See also

• List of chemical compounds with unusual names

References

1. Chester, Douglas O.; Elix, John A. (1979). "Three new aliphatic acids from lichens of genus Parmelia (Subgenus Xanthoparmelia)". Australian Journal of Chemistry. 32 (11): 2565–2569. doi:10.1071/CH9792565.
2. Kurokawa, Syo; Filson, Rex (1975). "New species of Parmelia from South Australia". Bulletin of the National Science Museum (Tokyo). Series B (Botany). 1 (1): 35–47.
3. Pérez-Vargas, Israel; Hernández-Padrón, Consuelo; Elix, John A. (2007). "A new species of Xanthoparmelia (Ascomycota: Parmeliaceae) from the Canary Islands". The Lichenologist. 39 (5): 445–449. doi:10.1017/S0024282907007189. S2CID 86682879.
4. Stocker-Wörgötter, Elfie (2015). "Biochemical Diversity and Ecology of Lichen-Forming Fungi: Lichen Substances, Chemosyndromic Variation and Origin of Polyketide-Type Metabolites (Biosynthetic Pathways)". In Upreti, Dalip Kumar; Divakar, Pradeep K.; Shukla, Vertika; Bajpai, Rajesh (eds.). Recent Advances in Lichenology. Modern Methods and Approaches in Lichen Systematics and Culture Techniques. Vol. 2. New Delhi: Springer. pp. 161–179. doi:10.1007/978-81-322-2235-4_9. ISBN 978-81-322-2234-7.
5. Din, Laily B.; Zakaria, Zuriati; Samsudin, Mohd Wahid; Elix, John A. (2010). "Chemical profile of compounds from lichens of Bukit Larut, Peninsular Malaysia" (PDF). Sains Malaysiana. 39 (6): 901–908.
6. Elix, John A.; Kantvilas, Gintaras (2009). "A new species of Protoparmelia (lichenized Ascomycota) from Australia". Nova Hedwigia. 89 (3–4): 355–360. doi:10.1127/0029-5035/2009/0089-0355. hdl:1885/57211. S2CID 84989424.
7. Kantvilas, Gintaras; Elix, John (2006). "Further notes on the genus Hertelidea, with a description of a new species". Australasian Lichenology. 59: 30–33.
8. Joshi, Yogesh; Wang, Xin Yu; Koh, Young Jin; Hur, Jae-Seoun (2010). "The lichen genus Lepraria (Stereocaulaceae) in South Korea". Mycotaxon. 112 (1): 201–217. doi:10.5248/112.201.
9. Canêz, Luciana S.; Spielmann, Adriano A.; Marcelli, Marcelo P.; Elix, John A. (2016). "An accurate circumscription of the poorly known Punctelia negata (Nyl.) Krog". Iheringia, Série Botânica. 71 (3): 257–260.
10. Shrestha, Gajendra; Raphael, Jocelyn; Leavitt, Steven D.; St. Clair, Larry L. (2014). "In vitro evaluation of the antibacterial activity of extracts from 34 species of North American lichens". Pharmaceutical Biology. 52 (10): 1262–1266. doi:10.3109/13880209.2014.889175. PMID 24863278. S2CID 20528049.
11. May, Paul (27 March 2019). "Molecules with Silly or Unusual Names". Bristol University. Retrieved 1 April 2021.
12. Mestel, Rosie (24 June 2002). "When Scientists Get Silly, Chemical Names Do Too". Los Angeles Times. Retrieved 1 April 2021.