Solorinic acid

Solorinic acid
Names
	IUPAC name 2-hexanoyl-1,3,8-trihydroxy-6-methoxyanthracene-9,10-dione
	Other names 2-n-hexanoyl-1,3,8-trihydroxy-6-methoxy-anthraquinone
Identifiers
CAS Number	10210-21-6;
3D model (JSmol)	Interactive image;
ChEBI	CHEBI:144072;
ChemSpider	90031;
PubChem CID	99653;
CompTox Dashboard (EPA)	DTXSID40144639 ;
	InChI InChI=1S/C21H20O7/c1-3-4-5-6-13(22)18-15(24)9-12-17(21(18)27)20(26)16-11(19(12)25)7-10(28-2)8-14(16)23/h7-9,23-24,27H,3-6H2,1-2H3 Key: MLTVHORGISIISB-UHFFFAOYSA-N;
	SMILES CCCCCC(=O)C1=C(C=C2C(=C1O)C(=O)C3=C(C2=O)C=C(C=C3O)OC)O;
Properties
Chemical formula	C21H20O7
Molar mass	384.384 g·mol−1
Appearance	orange-red crystals
Density	1.4±0.1 g/cm3
Melting point	201 °C (394 °F; 474 K)
Boiling point	613.4±55.0 °C
Hazards
Flash point	217.7±25.0 °C
	Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa). Infobox references

Solorinic acid is an anthraquinone pigment found in the leafy lichen Solorina crocea. It is responsible for the strong orange colour of the medulla and the underside of the thallus in that species. In its purified crystalline form, it exists as orange-red crystals with a melting point of 201 °C (394 °F).^[1]

The structure of solorinic acid, 2-n-hexanoyl-1,3,8-trihydroxy-6-methoxy-anthraquinone, was proposed by Koller and Russ in 1937,^[2] and verified by chemical synthesis in 1966.^[3]

Norsolorinic acid, (C₂₀H₁₈O₇, 2-hexanoyl-1,3,6,8-tetrahydroxyanthraquinone), is a closely related compound also found in Solorina crocea.^[3]

Solorinic acid was used as the internal standard in the establishment of a standardized method for the identification of lichen products using high-performance liquid chromatography. This is because it is quite a hydrophobic compound, and consequently will elute more slowly than most lichen products,^[4] making possible the identification of lichen extracts containing chlorinated xanthones or long chain depsides.^[5]

Although usually associated with Solorina crocea, solorinic acid was reported as a lichen product from the crustose, rock-dwelling lichen Placolecis kunmingensis, described as a species new to science in 2019.^[6]

References

^ Huneck, Siegfried (1996). Identification of Lichen Substances. Berlin, Heidelberg: Springer Berlin Heidelberg. p. 182. ISBN 978-3-642-85245-9. OCLC 851387266.
^ Koller, G.; Russ, H. (1937). "Über die Konstitution der Solorinsäure". Monatshefte für Chemie (in German). 70 (1): 54–72. doi:10.1007/bf01755655.
^ ^a ^b Anderson, H.A.; Thomson, R.H.; Wells, J. W. (1966). "Naturally occurring quinones. Part VIII. Solorinic acid and norsolorinic acid". Journal of the Chemical Society C: Organic: 1727–1729. doi:10.1039/j39660001727.
^ Feige, G.B.; Lumbsch, H.T.; Huneck, S.; Elix, J.A. (1993). "Identification of lichen substances by a standardized high-performance liquid chromatographic method". Journal of Chromatography A. 646 (2): 417–427. doi:10.1016/0021-9673(93)83356-W.
^ Le Pogam, Pierre; Herbette, Gaëtan; Boustie, Joël (2014). "Analysis of Lichen Metabolites, a Variety of Approaches". Recent Advances in Lichenology. New Delhi: Springer India. pp. 229–261 [248]. doi:10.1007/978-81-322-2181-4_11. ISBN 978-81-322-2180-7.
^ Yin, An Cheng; Wang, Xin Yu; Liu, Dong; Zhang, Yan Yun; Yang, Mei Xia; Li, Li Juan; Wang, Li Song (2019). "Two new species of Placolecis (lichenized Ascomycota) from China". Mycobiology. 47 (4): 401–407. doi:10.1080/12298093.2019.1672984. PMC 6968434. PMID 32010461.

[Huneck_1996-1] Huneck, Siegfried (1996). Identification of Lichen Substances. Berlin, Heidelberg: Springer Berlin Heidelberg. p. 182. ISBN 978-3-642-85245-9. OCLC 851387266.

[Koller_&_Russ_1937-2] Koller, G.; Russ, H. (1937). "Über die Konstitution der Solorinsäure". Monatshefte für Chemie (in German). 70 (1): 54–72. doi:10.1007/bf01755655.

[Anderson_et_al._1966-3] Anderson, H.A.; Thomson, R.H.; Wells, J. W. (1966). "Naturally occurring quinones. Part VIII. Solorinic acid and norsolorinic acid". Journal of the Chemical Society C: Organic: 1727–1729. doi:10.1039/j39660001727.

[Feige_et_al._1993-4] Feige, G.B.; Lumbsch, H.T.; Huneck, S.; Elix, J.A. (1993). "Identification of lichen substances by a standardized high-performance liquid chromatographic method". Journal of Chromatography A. 646 (2): 417–427. doi:10.1016/0021-9673(93)83356-W.

[Le_Pogam_et_al._2014-5] Le Pogam, Pierre; Herbette, Gaëtan; Boustie, Joël (2014). "Analysis of Lichen Metabolites, a Variety of Approaches". Recent Advances in Lichenology. New Delhi: Springer India. pp. 229–261 [248]. doi:10.1007/978-81-322-2181-4_11. ISBN 978-81-322-2180-7.

[Yin_et_al._2019-6] Yin, An Cheng; Wang, Xin Yu; Liu, Dong; Zhang, Yan Yun; Yang, Mei Xia; Li, Li Juan; Wang, Li Song (2019). "Two new species of Placolecis (lichenized Ascomycota) from China". Mycobiology. 47 (4): 401–407. doi:10.1080/12298093.2019.1672984. PMC 6968434. PMID 32010461.

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