Flavanone 8-dimethylallyltransferase in Sophora flavescens cell suspension cultures.
Dimethylallyl diphosphate: naringenin 8-dimethylallyltransferase (EC 2.5.1) was characterized. The enzyme was enantiospecific for (-)-(2S)-naringenin and utilized 3,3-dimethylallyl diphosphate as sole prenyl donor. It required Mg2+ (optimum concentration, 10 mM), and has an optimum pH of 9-10. The apparent Km values for 3,3-dimethylallyl diphosphate and naringenin were 120 and 36 microM, respectively. The microsomal fraction prenylated several other flavanones at the C-8 position less effectively as compared with naringenin. Interestingly, when 2'-hydroxynaringenin was used as a prenyl acceptor, the 8-lavandulyl (sophoraflavanone G) and the 6-dimethylallyl derivatives were formed, together with the 8-dimethylallyl derivative, leachianone G. These results suggest that the 2'-hydroxy group of naringenin plays an important role for the formation of a lavandulyl group.
Yamamoto
H
H
Department of Pharmacognosy, Gifu Pharmaceutical University, Japan.
Senda
M
M
Inoue
K
K
D019883:Alkyl and Aryl Transferases / Q000302:isolation & purification* / Q000378:metabolism; D002478:Cells, Cultured; D002851:Chromatography, High Pressure Liquid; D007887:Fabaceae / Q000737:chemistry* / Q000166:cytology; D008861:Microsomes / Q000201:enzymology / Q000378:metabolism; D010946:Plants, Medicinal; D013379:Substrate Specificity
D019883:Alkyl and Aryl Transferases; C417709:dimethylallyl diphosphate naringenin 8-dimethylallyltransferase