noun

• A red dye originally extracted from madder and also prepared artificially by the oxidation of alizarin.

  An anthraquinone derivative; chemical formula: C₁₄H₈O₅

  ‘Alizarin is the main colourant molecule, but the extract also contains a closely related compound called purpurin, which (despite the name) imparts an orange colour.’

  More example sentences

  • ‘Additionally, monascus pigments, purpurin, chlorophyllin and curcumin were reported to inhibit the mutagenicity of heterocyclic amines and other carcinogens.’
  • ‘In general, these newer drugs have been based on the structure of chlorin, purpurin, phthalocyanine or naphthalocyanine.’
  • ‘However, the addition of purpurin to oxidized cytochrome c in the absence of microsomal fraction demonstrated low level but dose-dependent ‘reductase-like’ activity.’