Lobaric acid

Lobaric acid
Names
	IUPAC name 3-Hydroxy-9-methoxy-6-oxo-7-pentanoyl-1-pentylbenzo[b][1,4]benzodioxepine-2-carboxylic acid
	Other names Lobraric acid; stereocaulic acid
Identifiers
CAS Number	522-53-2;
3D model (JSmol)	Interactive image;
PubChem CID	73157;
	InChI InChI=1S/C25H28O8/c1-4-6-8-9-15-21(24(28)29)18(27)13-20-23(15)32-19-12-14(31-3)11-16(17(26)10-7-5-2)22(19)25(30)33-20/h11-13,27H,4-10H2,1-3H3,(H,28,29) Key: JHEWMLHQNRHTQX-UHFFFAOYSA-N;
	SMILES CCCCCC1=C(C(=CC2=C1OC3=CC(=CC(=C3C(=O)O2)C(=O)CCCC)OC)O)C(=O)O;
Properties
Chemical formula	C25H28O8
Molar mass	456.491 g·mol−1
Melting point	196–198 °C (385–388 °F; 469–471 K)
	Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa). Infobox references

Lobaric acid is a chemical compound with the molecular formula C₂₅H₂₈O₈. It has been found in the Antarctic lichen Stereocaulon alpinum^[2] and a variety of other lichens. It is a member of the depsidone class of compounds.

The first total synthesis of lobaric acid was reported in 2018 by researchers at the Korea Polar Research Institute and Hanyang University. The synthesis was accomplished in 14 total steps, starting with 4-bromophthalic anhydride. Key steps included an Ullmann aryl ether coupling reaction to connect the two main aromatic rings, followed by a seven-membered lactonization reaction to form the final structure. The synthetic route also allowed access to several derivatives of lobaric acid, including methyllobarin, lobarin, and lobarstin, which showed significant protein tyrosine phosphatase 1B (PTP1B) inhibitory activities.^[3]

References

^ Morita, Hiroshi; Tsuchiya, Tomoe; Kishibe, Koji; Noya, Sayaka; Shiro, Motoo; Hirasawa, Yusuke (2009). "Antimitotic activity of lobaric acid and a new benzofuran, sakisacaulon a from Stereocaulon sasakii". Bioorganic & Medicinal Chemistry Letters. 19 (13): 3679–3681. doi:10.1016/j.bmcl.2009.03.170. PMID 19481447.
^ Tian, Yuan; Li, Yan-Ling; Zhao, Feng-Chun (2017). "Secondary Metabolites from Polar Organisms". Marine Drugs. 15 (3): 28. doi:10.3390/md15030028. PMC 5367009. PMID 28241505.
^ Kim, Tai Kyoung; Kim, Joung Eun; Youn, Ui Joung; Han, Se Jong; Kim, Il-Chan; Cho, Cheon-Gyu; Yim, Joung Han (2018). "Total Syntheses of Lobaric Acid and Its Derivatives from the Antarctic Lichen Stereocaulon alpinum". Journal of Natural Products. 81 (6): 1460–1467. doi:10.1021/acs.jnatprod.8b00227. PMID 29878768.

[1] Morita, Hiroshi; Tsuchiya, Tomoe; Kishibe, Koji; Noya, Sayaka; Shiro, Motoo; Hirasawa, Yusuke (2009). "Antimitotic activity of lobaric acid and a new benzofuran, sakisacaulon a from Stereocaulon sasakii". Bioorganic & Medicinal Chemistry Letters. 19 (13): 3679–3681. doi:10.1016/j.bmcl.2009.03.170. PMID 19481447.

[2] Tian, Yuan; Li, Yan-Ling; Zhao, Feng-Chun (2017). "Secondary Metabolites from Polar Organisms". Marine Drugs. 15 (3): 28. doi:10.3390/md15030028. PMC 5367009. PMID 28241505.

[3] Kim, Tai Kyoung; Kim, Joung Eun; Youn, Ui Joung; Han, Se Jong; Kim, Il-Chan; Cho, Cheon-Gyu; Yim, Joung Han (2018). "Total Syntheses of Lobaric Acid and Its Derivatives from the Antarctic Lichen Stereocaulon alpinum". Journal of Natural Products. 81 (6): 1460–1467. doi:10.1021/acs.jnatprod.8b00227. PMID 29878768.

[1]

[2]

[3]