Sekikaic acid

Sekikaic acid
Names
	IUPAC name 2-Hydroxy-3-(2-hydroxy-4-methoxy-6-propylbenzoyl)oxy-4-methoxy-6-propylbenzoic acid
Identifiers
CAS Number	607-11-4;
3D model (JSmol)	Interactive image;
ChEBI	CHEBI:144301;
ChEMBL	ChEMBL4649759;
PubChem CID	12315460;
	InChI InChI=1S/C22H26O8/c1-5-7-12-9-14(28-3)11-15(23)17(12)22(27)30-20-16(29-4)10-13(8-6-2)18(19(20)24)21(25)26/h9-11,23-24H,5-8H2,1-4H3,(H,25,26) Key: CPHXGYQLOSNELY-UHFFFAOYSA-N;
	SMILES CCCC1=CC(=C(C(=C1C(=O)O)O)OC(=O)C2=C(C=C(C=C2O)OC)CCC)OC;
Properties
Chemical formula	C22H26O8
Molar mass	418.442 g·mol−1
Appearance	Rectangular prisms or rhombic plates
Melting point	150–151 °C (302–304 °F; 423–424 K)
	Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa). Infobox references

Sekikaic acid is an organic compound in the structural class of chemicals known as depsides. It is found in some lichens. First isolated from Ramalina sekika, it is a fairly common lichen product in Ramalina and Cladonia, both genera of lichen-forming fungi.^[1] The species epithet of the powdery lichen Lepraria sekikaica refers to the presence of this substance—a rarity in genus Lepraria.^[2]

Properties

In its purified form, sekikaic acid exists as colourless rectangular prisms or rhombic plates. Its molecular formula is C₂₂H₂₆0₈. It has a melting point of 150–151 °C (302–304 °F). An ethanolic solution of sekikaic acid reacts with iron(III) chloride to produce a violet colour. Its ultraviolet spectrum has three peaks of maximum absorption (λ_max) at 219, 263, and 303 nm.^[3]

Sekikaic acid has been demonstrated to have several biological activities in laboratory experiments. These include antioxidant activity,^[4] inhibition of the enzymes α-glucosidase and α-amylase, hypoglycemic activity, and lipid-lowering activity.^[5] It also has antiviral activity against Respiratory syncytial virus, even more so than the standard antiviral medication ribavirin.^[6]

Related compounds

The sekikaic acid chemosyndrome contains similar compounds that are metabolically related to sekikaic acid. It comprises sekikaic acid as the major compound, and 4'O-demethylsekikaic and homosekikaic acids as satellite metabolites.^[7]

References

^ Culberson, Chicita (1970). "Supplement to "Chemical and Botanical Guide to Lichen Products"". The Bryologist. 73 (2): 177–377. doi:10.2307/3241261. JSTOR 3241261.
^ Lumbsch, H.T.; Ahti, T.; Altermann, S.; De Paz, G.A.; Aptroot, A.; Arup, U.; et al. (2011). "One hundred new species of lichenized fungi: a signature of undiscovered global diversity". Phytotaxa. 18 (1): 81–82. doi:10.11646/phytotaxa.18.1.1. hdl:11336/4198.
^ Huneck, Siegfried (1996). Identification of Lichen Substances. Berlin, Heidelberg: Springer Berlin Heidelberg. pp. 49, 115, 296–297. ISBN 978-3-642-85245-9. OCLC 851387266.
^ Sisodia, R.; Geol, M.; Verma, S.; Rani, A.; Dureja, P. (2013). "Antibacterial and antioxidant activity of lichen species Ramalina roesleri". Natural Product Research. 27 (23): 2235–2239. doi:10.1080/14786419.2013.811410. PMID 23822758.
^ Tatipamula, Vinay Bharadwaj; Annam, Satya Sowbhagya Priya; Nguyen, Ha Thi; Polimati, Haritha; Yejella, Rajendra Prasad (2020). "Sekikaic acid modulates pancreatic β-cells in streptozotocin-induced type 2 diabetic rats by inhibiting digestive enzymes". Natural Product Research. 35 (23): 5420–5424. doi:10.1080/14786419.2020.1775226. PMID 32498563.
^ Lai, Daowan; Odimegwu, Damian; Esimone, Charles; Grunwald, Thomas; Proksch, Peter (2013). "Phenolic compounds with in vitro activity against Respiratory Syncytial Virus from the Nigerian lichen Ramalina farinacea". Planta Medica. 79 (15): 1440–1446. doi:10.1055/s-0033-1350711. PMID 23970423.
^ Cordeiro, Lucimara M.C.; Iacomini, Marcello; Stocker-Wörgötter, Elfie (2004). "Culture studies and secondary compounds of six Ramalina species". Mycological Research. 108 (5): 489–497. doi:10.1017/s0953756204009402. PMID 15230001.

[Culberson_1970-1] Culberson, Chicita (1970). "Supplement to "Chemical and Botanical Guide to Lichen Products"". The Bryologist. 73 (2): 177–377. doi:10.2307/3241261. JSTOR 3241261.

[Lumbsch_et_al._2011-2] Lumbsch, H.T.; Ahti, T.; Altermann, S.; De Paz, G.A.; Aptroot, A.; Arup, U.; et al. (2011). "One hundred new species of lichenized fungi: a signature of undiscovered global diversity". Phytotaxa. 18 (1): 81–82. doi:10.11646/phytotaxa.18.1.1. hdl:11336/4198.

[Huneck_1996-3] Huneck, Siegfried (1996). Identification of Lichen Substances. Berlin, Heidelberg: Springer Berlin Heidelberg. pp. 49, 115, 296–297. ISBN 978-3-642-85245-9. OCLC 851387266.

[Sisodia_et_al._2013-4] Sisodia, R.; Geol, M.; Verma, S.; Rani, A.; Dureja, P. (2013). "Antibacterial and antioxidant activity of lichen species Ramalina roesleri". Natural Product Research. 27 (23): 2235–2239. doi:10.1080/14786419.2013.811410. PMID 23822758.

[Tatipamula_et_al._2020-5] Tatipamula, Vinay Bharadwaj; Annam, Satya Sowbhagya Priya; Nguyen, Ha Thi; Polimati, Haritha; Yejella, Rajendra Prasad (2020). "Sekikaic acid modulates pancreatic β-cells in streptozotocin-induced type 2 diabetic rats by inhibiting digestive enzymes". Natural Product Research. 35 (23): 5420–5424. doi:10.1080/14786419.2020.1775226. PMID 32498563.

[Lai_et_al._2013-6] Lai, Daowan; Odimegwu, Damian; Esimone, Charles; Grunwald, Thomas; Proksch, Peter (2013). "Phenolic compounds with in vitro activity against Respiratory Syncytial Virus from the Nigerian lichen Ramalina farinacea". Planta Medica. 79 (15): 1440–1446. doi:10.1055/s-0033-1350711. PMID 23970423.

[Cordeiro_et_al._2004-7] Cordeiro, Lucimara M.C.; Iacomini, Marcello; Stocker-Wörgötter, Elfie (2004). "Culture studies and secondary compounds of six Ramalina species". Mycological Research. 108 (5): 489–497. doi:10.1017/s0953756204009402. PMID 15230001.

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