Regioselectivity of 7-O-methyltransferase of poplar to flavones.
POMT-7, an O-methyltransferase from poplar (Populus deltoids) was used to modify a variety of flavonoid compounds. POMT-7 was able to transfer a methyl group to several flavonoids containing a C-7 hydroxyl group. However, POMT-7 showed a higher affinity toward flavonol and flavone such as apigenin, kaempferol, luteolin, and quercetin than flavanone and isoflavone. Based on comparison of HPLC retention times with authentic compounds and corresponding nuclear magnetic resonance spectroscopy data, the methylation position of the reaction products was determined to be at the hydroxyl group of C-7. Biotransformation kinetics indicated that the enzyme converted more than 80% of the apigenin, kaempferol, luteolin and quercetin substrates, which were added at concentration of 70 microM, into corresponding 7-methoxy compounds within 24 h.
Kim
Bong-Gyu
BG
Department of Bioscience and Biotechnology, Bio/Molecular Informatics Center, Konkuk University, Seoul 143-701, Republic of Korea.
Kim
Hojung
H
Hur
Hor-Gil
HG
Lim
Yoongho
Y
Ahn
Joong-Hoon
JH
D047309:Flavones / Q000737:chemistry*; D008780:Methyltransferases / Q000737:chemistry*; D032107:Populus / Q000201:enzymology*; D013379:Substrate Specificity
D047309:Flavones; D008780:Methyltransferases; C110900:isoflavone 7-O-methyltransferase