Antioxidative activity of ginkgolides against superoxide in an aprotic environment.
The terpene lactones ginkgolide A, ginkgolide B, ginkgolide C, ginkgolide J and bilobalide, which are components of a standardized extract (EGb 761) from leaves of Ginkgo biloba, as well as ginkgolide M from roots of G. biloba were studied regarding their reaction against superoxide (O2-) and hydroperoxyl radicals (HO2) in dimethyl sulfoxide as an aprotic solvent. It was found that the ginkgolides B, C, J, M as well as bilobalide react with superoxide and its protonated form as demonstrated by EPR and UV/VIS spectroscopy. The initial reaction rate with these oxygen-derived radicals is in the order of 100 M-1/s and below. Ginkgolide A does not react with superoxide under these conditions. From these findings it can be suggested that the superoxide scavenging effect of the ginkgolides B, C, J, M and bilobalide contributes to the antioxidant properties of G. biloba.
Scholtyssek
H
H
Clinic of Internal Medicine, Charité School of Medicine, Humboldt University, Berlin, Germany.
Damerau
W
W
Wessel
R
R
Schimke
I
I
D000975:Antioxidants / Q000737:chemistry*; D003517:Cyclopentanes / Q000737:chemistry*; D004121:Dimethyl Sulfoxide; D004224:Diterpenes; D004578:Electron Spin Resonance Spectroscopy; D016166:Free Radical Scavengers / Q000737:chemistry*; D005663:Furans / Q000737:chemistry*; D020441:Ginkgo biloba; D046934:Ginkgolides; D010936:Plant Extracts / Q000737:chemistry*; D013056:Spectrophotometry, Ultraviolet; D013481:Superoxides / Q000737:chemistry*; D000096983:Ginkgo Extract
D000975:Antioxidants; D003517:Cyclopentanes; D004121:Dimethyl Sulfoxide; D004224:Diterpenes; D016166:Free Radical Scavengers; D005663:Furans; D046934:Ginkgolides; D010936:Plant Extracts; D013481:Superoxides; C063170:Ginkgo biloba extract; D000096983:Ginkgo Extract; C073710:bilobalide