6-Methoxymellein is a dihydroisocoumarin, a phenolic compound found in carrots and carrot purées. It is responsible for bitterness in carrots.[1][2] It is a phytoalexin, induced in carrot slices by UV-C,[3] that allows resistance to Botrytis cinerea[4] and other microorganisms.[5]

6-Methoxymellein
Chemical structure of 6-Methoxymellein
Names
Preferred IUPAC name
8-Hydroxy-6-methoxy-3-methyl-3,4-dihydro-1H-2-benzopyran-1-one
Other names
8-Hydroxy-6-methoxy-3-methylisochroman-1-one
Identifiers
3D model (JSmol)
ChemSpider
UNII
  • InChI=1S/C11H12O4/c1-6-3-7-4-8(14-2)5-9(12)10(7)11(13)15-6/h4-6,12H,3H2,1-2H3
    Key: AIFNAMVERSBWPS-UHFFFAOYSA-N
  • InChI=1/C11H12O4/c1-6-3-7-4-8(14-2)5-9(12)10(7)11(13)15-6/h4-6,12H,3H2,1-2H3
    Key: AIFNAMVERSBWPS-UHFFFAOYAL
  • COc1cc(O)c2C(=O)OC(C)Cc2c1
Properties
C11H12O4
Molar mass 208.21 g/mol
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).

Biosynthesis

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6-Methoxymellein is formed from S-adenosyl methionine and 6-hydroxymellein by the enzyme 6-hydroxymellein O-methyltransferase with secondary production of S-adenosylhomocysteine.[6]

References

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  1. ^ Structural and Sensory Characterization of Compounds Contributing to the Bitter Off-Taste of Carrots (Daucus carota L.) and Carrot Puree. Andreas Czepa and Thomas Hofmann, J. Agric. Food Chem., 2003, 51, pages 3865-3873, doi:10.1021/jf034085+ PMID 12797757
  2. ^ Determination and Distribution of 6-Methoxymellein in Fresh and Processed Carrot Puree by a Rapid Spectrophotometric Assay. S.T. Talcott and L.R. Howard, J. Agric. Food Chem., 1999, 47 (8), pages 3237–3242, doi:10.1021/jf990288f
  3. ^ Induction of 6-Methoxymellein and Resistance to Storage Pathogens in Carrot Slices by UV-C. J. Mercier, J. Arul, R. Ponnampalam and M. Boulet, Journal of Phytopathology, Volume 137, Issue 1, pages 44–54, January 1993, doi:10.1111/j.1439-0434.1993.tb01324.x
  4. ^ Cell death, 6-methoxymellein accumulation, and induced resistance to Botrytis cinerea in carrot root slices. R. Hoffman and J.B. Heale, Physiological and Molecular Plant Pathology, Volume 30, Issue 1, January 1987, Pages 67–75, doi:10.1016/0885-5765(87)90083-X
  5. ^ Isolation and antimicrobial activity of the phytoalexin 6-methoxymellein from cultured carrot cells. Fumiya Kurosaki and Arasuke Nishi, Phytochemistry, Volume 22, Issue 3, 1983, Pages 669–672, doi:10.1016/S0031-9422(00)86959-9
  6. ^ "MetaCyc 6-methoxymellein biosynthesis". www.biocyc.org.
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