EC 2.4.2.35

Reaction: UDP-D-xylose + a flavonol 3-O-glycoside = UDP + a flavonol 3-[β-D-xylosyl-(12)-β-D-glycoside]

For diagram click here.

Systematic name: UDP-D-xylose:flavonol-3-O-glycoside 2"-O-β-D-xylosyltransferase

Comments: Flavonol 3-O-glucoside, flavonol 3-O-galactoside and, more slowly, rutin, can act as acceptors.

Links to other databases: BRENDA, EXPASY, KEGG, Metacyc, CAS registry number: 83380-90-9

References:

1. Kleinehollenhorst, G., Behrens, H., Pegels, G., Srunk, N. and Wiermann, R. Formation of flavonol 3-O-diglycosides and flavonol 3-O-triglycosides by enzyme extracts from anthers of Tulipa cv. Apeldoorn. Z. Naturforsch. C: Biosci. 37 (1982) 587-599.

2. Ishikura, N. and Yang, Z.Q. UDP-D-xylose: flavonol 3-O-xylosyltransferase from young leaves of Euonymus alatus f. ciliato-dentatus. Z. Naturforsch. C: Biosci. 46 (1991) 1003-1010.