Influence of antivitamins ginkgotoxin 5'-phosphate and deoxypyridoxine 5'-phosphate on human pyridoxine 5'-phosphate oxidase.

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 B(6) antivitamin which may cause epileptic convulsions, other severe neuronal disorders and even death, is also found in Ginkgo leaves and leaf-derived remedies.