Planta Med 2002; 68(10): 934-936
DOI: 10.1055/s-2002-34936
Letter
© Georg Thieme Verlag Stuttgart · New York

Isolation and Identification of 6-Methylapigenin, a Competitive Ligand for the Brain GABAA Receptors, from Valeriana wallichii

Cristina Wasowski1 , Mariel Marder1 , Haydeé Viola2 , Jorge Horacio Medina2 , Alejandro Constantino Paladini1
  • 1Instituto de Química y Fisicoquímica Biológicas, Facultad de Farmacia y Bioquímica, Juín, Buenos Aires, Argentina
  • 2Instituto de Biología Celular y Neurociencias, Facultad de Medicina, Parguay, Buenos Aires, Argentina
Further Information

Publication History

Received: April 8, 2002

Accepted: June 29, 2002

Publication Date:
21 October 2002 (online)

Abstract

Using the guidance by a competitive assay for the benzodiazepine binding site in the GABAA receptor, active compounds were isolated from the rhizomes and roots of Valeriana wallichii DC. The UV, NMR and mass spectral data permitted the identification of 6-methylapigenin. This flavonoid has a Ki = 495 nM for the BDZ-bs and a GABA ratio of 1.6 - 2.0, which suggests possible agonistic properties. The calculated percentage of 6-methylapigenin in the crude drug is in the range: 0.013 % to 0.0013 %.

Abbreviations

BDZ-bs:benzodiazepine binding site

GABA ratio:gamma amino butyric acid ratio

GABAA:gamma amino butyric acid type A receptor

3H-FNZ:tritium flunitrazepam

Ki:inhibition constant

References

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  • 4 Medina J H, Paladini A C, Wolfman C, Levi de Stein M, Calvo D, Diaz L. et al . Chrysin (5,7-di-OH-flavone), a naturally-occurring ligand for benzodiazepine receptors with anticonvulsant properties.  Biochem Pharmacol. 1990;  40 2227-32
  • 5 Braestrup C, Honore T, Nielsen M, Petersen E N, Jensen L H. Ligands for benzodiazepine receptors with positive and negative efficacy.  Biochem Pharmacol. 1984;  33 859-62
  • 6 Markham K R, Geiger H. 1H nuclear magnetic resonance spectroscopy of flavonoids and their glycosides in hexadeuterodimethyl sulfoxide, Table 10.1, in The Flavonoids. Advances in Research since 1986. Harborne, J. B. editor Chapman and Hall London; 1994: 446

Alejandro C. Paladini

Instituto de Química y Fisicoquímica Biológicas

Facultad de Farmacia y Bioquímica

Junín 956 (1113)

Buenos Aires

Argentina

Phone: 00 54 11 4 962 5506

Fax: 00 54 11 4 962 5457

Email: paladini@qb.ffyb.uba.ar