| | 1 | Author
| Gary Kuroki, JonathanE. Poulton | Requires cookie* | | | Title
| The Para-O-Methylation of Apigenin to Acacetin by Cell-Free Extracts of Robinia pseudoacacia L  | | | | Abstract
| Crude extracts from young Robinia pseudoacacia seedlings, shoots, and callus tissue catalyze the />ara-0-methylation of apigenin to acacetin using S-adenosyl-L-methionine as methyl donor. Optimum activity was exhibited at pH 9.0, and Mg2+ was not required for maximum activity. EDTA (10 m M) did not affect the reaction rate, but 47% inhibition was observed with SAH (100 u m). /?-Mercaptoethanol (5 m M) was required in the homogenization medium for optimum O-methyltransferase activity. Apigenin (K m, 50 hm) was the best substrate, but significant activity was shown towards caffeic acid, 5-hydroxyferulic acid, naringenin, and quercetin. Para-coumaric, ferulic, and sinapic acids were not methylated. The Km for S-adenosyl-L-methionine was 31 hm. Our demonstration o f a /wra-O-methyltransferase activity methylating apigenin, but not /rara-coumaric acid, strongly supports the conclusion that the B-ring methylation pattern of acacetin is determined at the C15-level in Robinia pseudoacacia. | | | |
Reference
| Z. Naturforsch. 36c, 916 (1981); received July 6 1981 | | | |
Published
| 1981 | | | |
Keywords
| Robinia pseudoacacia, Biosynthesis, Flavonoids, Para-O-Methyltransferase, Acacetin | | | |
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| default:Reihe_C/36/ZNC-1981-36c-0916.pdf | | | | Identifier
| ZNC-1981-36c-0916 | | | | Volume
| 36 | |
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