Journal of Fluorescence

, Volume 17, Issue 6, pp 707–714 | Cite as

Acidichromism and Ionochromism of Luteolin and Apigenin, the Main Components of the Naturally Occurring Yellow Weld: A Spectrophotometric and Fluorimetric Study

  • G. Favaro
  • C. Clementi
  • A. Romani
  • V. Vickackaite
Original Paper


Luteolin and apigenin, extracted from Reseda luteola L., were spectrophotometrically and fluorimetrically studied. The spectra were investigated as a function of pH in methanol/water solutions (1/2, v/v) in the 2–12 pH range. The absorption spectra markedly shifted to the red by increasing the pH. Three acid–base dissociation steps were detected for luteolin (pK a = 6.9; 8.6; 10.3) and two for apigenin (pK a = 6.6; 9.3). Fluorescence emission was very weak or undetectable (Φ F < 10−4) in acidic solution, but increased in intensity with increasing the pH. Both molecules exhibited a great propensity towards complex formation with metal ions, with association constants on the order of 105–107 for the first complexation step; in the presence of excess Al3+ ions, multiple equilibria were detected. A marked fluorescence enhancement was observed upon complexation with Al3+ ions (Φ F ∼ 1 for luteolin and ∼10−2 for apigenin).


Luteolin Apigenin UV-visible spectrophotometry UV-visible fluorimetry 



The research was funded by the Ministero per l’Università e la Ricerca Scientifica e Tecnologica (Rome) and the University of Perugia. One of us (V.V.) is grateful to the Italian Consiglio Nazionale delle Ricerche for a fellowship NATO CNR OUTREACH.


  1. 1.
    Cerrato A, De Santis D, Moresi M (2002) Production of luteolin extracts from Reseda luteola and assessment of their dyeing properties. J Sci Food Agric 82:1189–1199CrossRefGoogle Scholar
  2. 2.
    Hofenk de Graaff JH (2004) The colourful past. Abegg-Stiftung and Archetype, London, pp 215–219Google Scholar
  3. 3.
    Saunders D, Kirby J (1994) Light-induced colour changes in red and yellow lake pigments. Natl Gallery Tech Bull 15:79–97Google Scholar
  4. 4.
    Wouters J, Rosario-Chirinos N (1992) Dye Analysis of Pre-columbian Peruvian Textiles with High Performance Liquid Chromatography and Diode-Array Detection. J Am Inst Conserv 31:237–255CrossRefGoogle Scholar
  5. 5.
    Miliani C, Romani A, Favaro G (1998) A spectrophotometric and fluorimetric study of some anthraquinoid and indigoid colorants used in artistic paintings. Spectrochim Acta Part A 54:581–588CrossRefGoogle Scholar
  6. 6.
    Miliani C, Romani A, Favaro G (2000) Acidichromic effects in 1,2-di- and 1,2,4-tri-hydroxyanthraquinones. A spectrophotometric and fluorimetric study. J Phys Org Chem 13:141–150CrossRefGoogle Scholar
  7. 7.
    Clementi C, Romani A, Miliani C, Favaro G (2006) In situ fluorimetry: a powerful non-invasive diagnostic technique for natural dyes used in artefacts. Part I: Spectral characterization of orcein in solution, on silk and wool laboratory-standards and a fragment of Renaissance tapestry. Spectrochim Acta Part A 64:906–912CrossRefGoogle Scholar
  8. 8.
    Favaro G, Miliani C, Romani A, Vagnini M (2002) Role of protolytic interactions in photo-aging processes of carminic acid and carminic lake in solution and painted layers. J Chem Soc Perkin Faraday Trans 2:192–197Google Scholar
  9. 9.
    Shimoyama S, Noda Y (1994) Non-destructive determination of plant dyestuffs used for ancient madder dyeing, employing a three-dimentional fluorescence spectrum technique. Dyes Hist Archaeol 13:14–26Google Scholar
  10. 10.
    Meech SR, Phillips D (1983) Photophysics of some common fluorescence standards. J Photochem 23:193–217CrossRefGoogle Scholar
  11. 11.
    Thamer BJ, Voigt AF (1952) The spectrophotometric determination of overlapping dissociation constants of dibasic acids. J Phys Chem 56:225–232CrossRefGoogle Scholar
  12. 12.
    Wolfbeis OS, Begum M, Geiger H (1984) Fluorescence Properties of Hydroxy- and Methoxyflavones and the Effect of Shift Reagents. Z Naturforsch 39b:231–237Google Scholar
  13. 13.
    Seely GR, Jensen RG (1965) Effect of solvent on the spectrum of chlorophyll. Spectrochim Acta 21:1835–1845CrossRefGoogle Scholar
  14. 14.
    Du H, Fuh RA, Li J, Corkan A, Lindsey JS (1998) Photochem CAD: A computer-aided design and research tool in photochemistry. Photochem Photobiol 68:141–142CrossRefGoogle Scholar
  15. 15.
    Herrero-Martinez JM, Sanmartin M, Roses M, Bosch E, Rafols C (2005) Determination of dissociation constants of flavonoids by capillary electrophoresis. Electrophoresis 26:1886–1895PubMedCrossRefGoogle Scholar
  16. 16.
    Wolfbeiss OS, Begun M, Geiger H (1987) The fluorescence properties of luteolins. Monatsh Chem 118:1403–1411CrossRefGoogle Scholar
  17. 17.
    Karadag R (2003) Potentiometric and Spectrophotometric Determination of the Stability Constant of Luteolin (3′,4′,5,7-tetrahydroxyflavone) Complexes with Aluminium (III) and Iron (III). Chem Anal (Warsav) 48:931–937Google Scholar
  18. 18.
    Cornard JP, Merlin JC (2001) Structural and spectroscopic investigation of 5-hydroxyflavone and its complex with aluminium. J Mol Struct 569:129–138CrossRefGoogle Scholar
  19. 19.
    Cornard JP, Merlin JC (2003) Comparison of chelating power in hydroxyflavones. J Mol Struct 651–653:381–387CrossRefGoogle Scholar
  20. 20.
    Cornard JP, Boudet AC, Merlin JC (2001) Complexes of Al(III) 3′4′-dihydroxy-flavone: characterization, theoretical and spectroscopic study. Spectrochim Acta Part A 57:591–602CrossRefGoogle Scholar
  21. 21.
    Porter LJ, Markham KR (1970) Aluminum(III) complexes of hydroxyflavones in absolute methanol. I. Ligands containing only one chelating site. J Chem Soc C: Organic: 344–349Google Scholar
  22. 22.
    Alluis B, Dangles O (1999) Acylated flavone glucosides: synthesis, conformational investigation, and complexation properties. Helv Chim Acta 82:2201–2212CrossRefGoogle Scholar
  23. 23.
    Deng H, van Berkel GJ (1998) Electrospray Mass spectrometry and UV/Visible spectrophotometry studies of aluminium (III)-flavonoid complexes. J Mass Spectrom 33:1080–1087CrossRefGoogle Scholar
  24. 24.
    Boudet AC, Cornard JP, Merlin JC (2000) Conformational and spectroscopic investigation of 3-hydroxyflavone-aluminium chelates. Spectrochim Acta Part A 56:829–839CrossRefGoogle Scholar
  25. 25.
    Smith GJ, Thomsen SJ, Markham KR, Andary C, Cardon D (2000) The photostabilities of naturally occurring 5-hydroxyflavones, flavonols, their glycosides and their aluminum complexes. J Photochem Photobiol A: Chem 136:87–91CrossRefGoogle Scholar
  26. 26.
    Sathish S, Narayan G, Rao N, Janardhana C (2007) A Self-Organized Ensemble of Fluorescent 3-Hydroxyflavone-Al(III) Complex as Sensor for Fluoride and Acetate Ions. J Fluoresc 17:1–5PubMedCrossRefGoogle Scholar

Copyright information

© Springer Science+Business Media, LLC 2007

Authors and Affiliations

  • G. Favaro
    • 1
  • C. Clementi
    • 1
  • A. Romani
    • 1
  • V. Vickackaite
    • 2
  1. 1.Department of ChemistryUniversity of PerugiaPerugiaItaly
  2. 2.Department of Analytical and Environmental ChemistryVilnius UniversityVilniusLithuania

Personalised recommendations