Flavonoid glycosides

• The more the number of -OH-groups

  The darker the colour
• Flavonoid glycosides


  Play a role in protecting the tissues from UV-radiation
• Flavonoid glycosides

  • Due to the fungicide effects, it has plant protective role
• 2 phenylchromones


  • flavones
  • flavonols and its dimers
  • flavonones
  • dihydroflavonols
• 2 phenyl benzopyryliums


  Anthocyanidins (common plant pigments)
• Chalcones and dihydrochalcones


  Pyran-ring (not core) with an open form
• Flavones


  Flavones bearing -OCH3 next to -OH-group
• Flavones

  • Citrus sp.
• Flavones

  • strobopinin (Pinus sp.) at C3 and C6
  • artocaprin (Artocarpus sp.)
• C glycosides


  • apigenin + glucose - vitexin
  • apigenin + glucose - isovitexin (glucose bound at C6 position)
• 1. Glycosides


  • apigenin + glucose + apiose - apioside
  • diosmetin-7-rutinoside - diosmin (Citrus sp.)
• Flavonols


  • galangin
  • kaempferol
  • quercetol
  • myricetin
• Flavanones

  hesperetin + glucose + rhamnose - hesperidin (widespread in Citrus species)
• Isoflavones

  Colourless compounds, not widespread in nature
• Isoflavones


  • Structurally similar to 17b-estradiol, thereby they easily bind to estrogen receptors
  • Show agonist / antagonist activity
  • Help relief of postmenopausal symptoms
• Isoflavone drugs

  • Daidzenin, Gynogen
• İsoflavone

  • Rotenoids
  • Cholesterol-lowering
  • Protective against cardiovascular diseases
  • Antioxidant
• Chalcones


  • Yellow coloured
  • In alkaline medium turns into red
  • Non-stable structure -> easily ring-closure and converted into flavanones
  • Found in Fabaceae
• Dihydrochalcones

  Reduced form of chalcone
• Anthocyanidins


  • Pigments that give colour to flowers, leaves, fruits
  • Soluble in water and alcohol
  • Insoluble in non-polar solvents
  • Instable structure
• Anthocyanidins


  • Pelargonidin
  • Delfinidol
  • Peonidin
  • Malvidin
• pH < 3

  Anthocyanidins are red (cationic structure is stable)
• pH 4-6

  Anthocyanidins are blue-violet
• Neutral / slightly acidic pH

  Anthocyanidins are colourless or poor colour
• Proanthocyanidins


  Most common proanthocyanidin is catechol