Example
Synthesis of Novel Flavonoids by Combination of Plant Flavonoids and
Microbial Glycosides
Tae Jin Oh and Jae Kyung Sohng
Department of Pharmaceutical Engineering, Institute of Biomolecule Reconstruction, Sun Moon University,
Asansi, Chungnam, 336-708, Korea
E-mail: sohng@sunmoon.ac.kr, Tel:82-41-530-2246, Fax: 82-41-544-2919
Flavonoids comprise a large group of low molecular weight polyphenolic secondary plant
metabolites. It is important natural pharmaceutical compounds found showing antioxidant,
antibacterial and anti-viral activities as well as anti-allergic effects, and possess antiinflammatory, anti-angiogenic, analgesic, hepatoprotective, cytostatic, apoptotic estrogenic or
anti-estrogenic properties. Biosynthesis of glycosylated natural compound results in the
formation of an overwhelming number of natural glycosides with numerous applications like
solubility, stabilization and detoxification .
The engineered E. coli BL21(DE3, △pgi) cells generated by deleting the glucose-phosphate
isomerase
(pgi)
gene
and
heterologously
expressing
TDP-deoxysugar,
TDP-
aminodeoxysugar and glycosyltransferase genes from various sources were used as whole
cell biotransformation reaction by feeding exogeneously. To generate glycosylated flavonoids,
the engineered E. coli cells were fed with quercetin, keampferol and fisetin, the flavonol (or
3-hydroxyflavone) exogenously.
flavonoids,
3-O-deoxyallose
The products were analyzed to be 3-O-rhamnosylflavonoids,
7-O-glucuronyl
flavonoids
and
3-O-
aminodeoxysugar flavonoids. Since the deoxysugar glycosylated flavonoids increase
antibacterial activity and have shown enormous pharmaceutical properties, the recombinant
host generated can be utilize to discover unusual glycosylated flavonoids as functional
materials and drugs.
Acknowledgment
This work was supported by a grant from the Next-Generation BioGreen 21 Program (SSAC,
grant#: PJ008013), Rural Development Administration, Republic of Korea.