TAILIEUCHUNG - Báo cáo khoa học: The human pyridoxal kinase, a plausible target for ginkgotoxin from Ginkgo biloba

Ginkgotoxin (4¢-O-methylpyridoxine) occurring in the seeds and leaves of Ginkgo biloba, is an antivitamin structurally related to vitamin B6. Ingestion of ginkgotoxin triggers epileptic convulsions and other neuronal symptoms. Here we report on studies on the impact of B6 antivitamins including ginkgo- | ễFEBS Journal The human pyridoxal kinase a plausible target for ginkgotoxin from Ginkgo biloba Uta Kastner1 Christian Hallmen2 Michael Wiese2 Eckhard Leistner1 and Christel Drewke1 1 Institut fur Pharmazeutische Biologie Universitat Bonn Germany 2 Pharmazeutisches Institut Pharmazeutische Chemie Endenich Bonn Germany Keywords Ginkgo biloba ginkgotoxin pyridoxal kinase c-aminobutyric acid pyridoxal phosphate Correspondence C. Drewke Institut fur Pharmazeutische Biologie Rheinische Friedrich-Wilhelms-Universitat Bonn Nussallee 6 53115 Bonn Germany Fax 49 228 733250 Tel. 49 228 732563 E-mail cdrewke@ Website http pharmbio Received 5 September 2006 revised 11 December 2006 accepted 15 December 2006 doi Ginkgotoxin 4 -ơ-methylpyridoxine occurring in the seeds and leaves of Ginkgo biloba is an antivitamin structurally related to vitamin B6. Ingestion of ginkgotoxin triggers epileptic convulsions and other neuronal symptoms. Here we report on studies on the impact of B6 antivitamins including ginkgotoxin on recombinant homogeneous human pyridoxal kinase EC . It is shown that ginkgotoxin serves as an alternate substrate for this enzyme with a lower Km value than pyridoxal pyridoxamine or pyridoxine. Thus the presence of ginkgotoxin leads to temporarily reduced pyridoxal phosphate formation in vitro and possibly also in vivo. Our observations are discussed in light of Ginkgo medications used as nootropics. 4 -ơ-methylpyridoxine MPN ginkgotoxin Fig. 1 is a neurotoxic compound that causes severe neuronal disorders in mammals after ingestion. Symptoms of this poisoning called gin-nan sitotoxism are mainly epileptic convulsions paralysis of the legs and loss of consciousness 1 . There are even reports of death due to overconsumption of Ginkgo seeds which are the main source of ginkgotoxin 1 . In addition to the seeds which accumulate the toxin ginkgotoxin has also been found in the leaves of Ginkgo biloba as .

• Báo cáo khoa học
• Report medicine
• traditional medicine
• scientific reports
• medicine
• cell proliferation
• oxidation
• medical knowledge
• medical research
• analysis of cytoplasmic
• Crystal structure
• bacteria
• hemoglobin
• breast cancer
• chemical reaction
• gastric cancer
• hormone medicine
• tumor cells
• biochemical studies
• environmental medicine