Xerocomorubin is a pigment from the fungus order Boletales. It is the oxidized form of isoxerocomic acid.[1] Air oxidation is responsible its formation, and it oxidizes faster to a similar pulvinic acid type pigment oxidized variant, variegatorubin.[1][2] The long wavelength has an absorption at 497 nm, 106 nm higher than its precursor isoxerocomic acid. Synthesis experiments have shown tetra-acetylation by acetic anhydride and sulfuric acid. Although xerocomorubin and variegatorubin give off the same deep red color and could simultaneously occur in a mushroom, extracts from the deep red colored mushroom Boletus rubellus Krombh. identified only variegatorubin by thin layer chromatography (TLC), leading to the question the natural abundance of xerocomorubin.

Xerocomorubin
Names
IUPAC name
5,6-Dihydroxy-3-[3-hydroxy-4-(4-hydroxyphenyl)-5-oxo-2(5H)-furanylidene]-2(3H)-benzofuranone
Identifiers
3D model (JSmol)
  • InChI=1S/C18H10O8/c19-8-3-1-7(2-4-8)13-15(22)16(26-17(13)23)14-9-5-10(20)11(21)6-12(9)25-18(14)24/h1-6,19-22H/b16-14+
    Key: KSBHFBKGAVZFRD-JQIJEIRASA-N
  • c1cc(O)ccc1C(=C(O)2)C(=O)OC2=C3C(=O)OC4=C3C=C(O)C(O)=C4
Properties
C18H10O8
Molar mass 354.270 g·mol−1
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).

References

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  1. ^ a b Gill, M., and Steglich, W. (1987). "Pigments of Fungi (Macromycetes)". Fortschritte der Chemie organischer Naturstoffe / Progress in the Chemistry of Organic Natural Products. Vol. 51. pp. 1–317. doi:10.1007/978-3-7091-6971-1_1. ISBN 978-3-7091-7456-2. PMID 3315906. {{cite book}}: |journal= ignored (help)CS1 maint: multiple names: authors list (link)
  2. ^ Edwards and Gill (1973). "Constituents of the Higher Fungi. Part X1l.l Identification of lnvolutin as (-)-cis-5-(3,4-Dihydroxyphenyl)-3,4-dihydroxy-2-(4-hydroxyphenyl)-cyclopent-2-enone and Synthesis of (+)-cis-lnvolutin Trimethyl Ether from Isoxerocomic Acid Derivatives". {{cite journal}}: Cite journal requires |journal= (help)