A. Arenz et al., OCCURRENCE OF NEUROTOXIC 4'-O-METHYLPYRIDOXINE IN GINKGO-BILOBA LEAVES, GINKGO MEDICATIONS AND JAPANESE GINKGO FOOD, Planta medica, 62(6), 1996, pp. 548-551
4'-O-Methylpyridoxine (ginkgotoxin) is a neurotoxic antivitamin B-6 wh
ich occurs in Ginkgo biloba L. seeds. Contrary to a previous report by
Wada et al. (15), the toxin was also detected in Ginkgo biloba leaves
. The leaves are a source of extracts (e.g. EGb761) employed in the pr
eparation of Ginkgo medications. Consequently the toxin ws also presen
t in Ginkgo medications and is even detectable in homoeopathic prepara
tions. The toxin occurs also in boiled Japanese Ginkgo food. However,
the amount of the toxin is likely to-be too low to exert a detrimental
effect after administration of the medication or ingestion of food.