Expression and Characterization of the Human Intestinal Bacterial Enzyme Which Cleaves the C-Glycosidic Bond in 3″-Oxo-puerarin

Puerarin (daidzein 8-C-glucoside) is an isoflavone C-glucoside contained in the roots of Pueraria lobata OHWI. We have previously isolated the human intestinal bacterium, strain PUE, which metabolizes puerarin to daidzein, though the enzyme which cleaves C-glycosidic bond has not been clarified. Her...

Full description

Saved in:
Bibliographic Details
Published in:Biological & pharmaceutical bulletin 2019/03/01, Vol.42(3), pp.417-423
Main Authors: Nakamura, Kenichi, Zhu, Shu, Komatsu, Katsuko, Hattori, Masao, Iwashima, Makoto
Format: Article
Language:English
Subjects:
bacterial enzyme
C-glucoside
Daidzein
Deglycosylation
Enzymes
human intestinal bacterium
Intermediates
Intestine
Isoflavones
Oxidation
puerarin
reaction intermediate
Citations: Items that this one cites
Items that cite this one
Online Access:Get full text
Tags: Add Tag
No Tags, Be the first to tag this record!
Description
Summary:Puerarin (daidzein 8-C-glucoside) is an isoflavone C-glucoside contained in the roots of Pueraria lobata OHWI. We have previously isolated the human intestinal bacterium, strain PUE, which metabolizes puerarin to daidzein, though the enzyme which cleaves C-glycosidic bond has not been clarified. Here, we identified one of the intermediates of enzymatic puerarin C-deglycosylation reaction as 3″-oxo-puerarin (1): C-3 in the glucose moiety connecting to hydroxyl is oxidized to ketone group. 1 was easily isomerized to the mixture of 1, 2″-oxo-puerarin (2a) and cyclic acetal (2b) of 2a in non-enzymatic condition. We identified the putative puerarin-metabolizing operon of strain PUE composed of 8 genes (dgpA–H). Among them, DgpB–C complex was expressed in Escherichia coli, which cleaved the C-glycosidic bond in 1 but not puerarin. These results suggested that the puerarin C-deglycosylation reaction is a two-step enzymatic reaction, including the oxidation reaction at C-3″ in puerarin to give 1, and the subsequent C-deglycosylation of 1 to provide daidzein.
ISSN:0918-6158
1347-5215
DOI:10.1248/bpb.b18-00729