Planta Med 2009; 75(6): 563-567
DOI: 10.1055/s-0029-1185482
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Original Paper
© Georg Thieme Verlag KG Stuttgart · New York

Influence of Antivitamins Ginkgotoxin 5′-Phosphate and Deoxypyridoxine 5′-Phosphate on Human Pyridoxine 5′-Phosphate Oxidase[*]

Nora Salamon1 , Cristian Gurgui1 , Eckhard Leistner1 , Christel Drewke1
  • 1Institute of Pharmaceutical Biology, University of Bonn, Bonn, Germany
Further Information

Publication History

received Dec. 18, 2008 revised January 28, 2009

accepted February 12, 2009

Publication Date:
13 March 2009 (online)

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Abstract

The pharmacological effects of leaf extracts (EGb 761) from Ginkgo biloba L. are attributed to ginkgolides, bilobalide and biflavonoids. However, besides these beneficial attributes, ginkgotoxin, a B6 antivitamin which may cause epileptic convulsions, other severe neuronal disorders and even death, is also found in Ginkgo leaves and leaf-derived remedies. Because of its structural similarity to the B6 vitamers, an interaction of ginkgotoxin with enzymes involved in the vitamin B6-dependent metabolism of the human brain is possible. This led us to investigate how the neurotoxic ginkgotoxin acts in the brain. To this end the gene coding for the human pyridoxine 5′-phosphate oxidase was heterologously overexpressed in E. coli and the homogeneous enzyme was characterized. The investigation showed that the enzyme is inhibited in vitro by the synthetic vitamin B6 derivative 4′-deoxypyridoxine 5′-phosphate but not by ginkgotoxin or its 5′-phosphate.

1 Dedicated to Dr. Heinz G. Floss on the occasion of his 75th birthday.

References

1 Dedicated to Dr. Heinz G. Floss on the occasion of his 75th birthday.

Dr. C. Drewke

Institute of Pharmaceutical Biology
University of Bonn

Nussallee 6

53115 Bonn

Germany

Phone: + 49 2 28 73 25 63

Fax: + 49 2 28 73 32 50

Email: cdrewke@uni-bonn.de