Methylation of 3′,4′ Di-O H C-Glycosyl-flavones in Silene

Autor: Jan van Brederode, R. Kamps-Heinsbroek
Rok vydání: 1981
Předmět:
Zdroj: Zeitschrift für Naturforschung C. 36:486-487
ISSN: 1865-7125
0939-5075
DOI: 10.1515/znc-1981-5-625
Popis: In green parts of Silene plants of the genotype glR two methylated flavonoids were found: isoscoparin and isosco-parin 2″-O-rhamnoside. An enzyme has been demonstrated to catalyze the transfer of the methyl moiety of S-adenosyl methionine to iso-orientin and iso-orientin 2″-O-rhamnosi-de. Maximal activity takes place at pH 8.0 -8 .2 . Of the metal ions Mn2+, Mg2+, Ca2+, Co2+, Zn2+ and Hg2+, only Co2+ stimulated the reaction at conc. > 2 mM . For the methyla­ tion of isoorientin the Km values were 4 × 10-6 M for S-ade-nosyl methionine and 0.32 × 10-3 m for iso-orientin. When isoorientin 2″-O-rhamnoside was used as substrate the Km values were 5 × 10-6 m for S-adenosylmethionine and 7 × 10-6 M for iso-orientin 2″-O-rhamnoside.
Databáze: OpenAIRE