107163-34-8Relevant articles and documents
Ep7GT, a glycosyltransferase with sugar donor flexibility from: Epimedium pseudowushanense, catalyzes the 7- O -glycosylation of baohuoside
Feng, Keping,Chen, Ridao,Xie, Kebo,Chen, Dawei,Liu, Jimei,Du, Wenyu,Yang, Lin,Dai, Jungui
, p. 8106 - 8114 (2019)
Icariin (1a), a 7-O-glycosylated flavonoid glycoside, is recognized as the major pharmacologically active ingredient of Epimedium plants, which have been used in traditional Chinese medicine for thousands of years. However, no glycosyltransferase (GT) responsible for the 7-O-glycosylation of flavonoids has been identified from Epimedium plants to date. Herein, a GT, Ep7GT, was identified from E. pseudowushanense B. L. Guo, which can regiospecifically transfer a glucose moiety to baohuoside (1) at 7-OH to form icariin (1a). Ep7GT showed a rare broad donor substrate spectrum, including UDP-glucose, UDP-xylose, UDP-N-acetylglucosamine, UDP-rhamnose, UDP-galactose, UDP-glucuronic acid and TDP-glucose. Moreover, two new derivatives of icariin (1a), 7-O-β-d-[2-(acetylamino)-2-deoxy-glucopyranosyl]-baohuoside (1b) and 7-O-β-d-xylosyl-baohuoside (1c), were biosynthesized by using Ep7GT in vitro. Engineered Escherichia coli harbouring Ep7GT was constructed, and 10.1 μg mL-1 icariin (1a) was yielded by whole-cell biotransformation with baohuoside (1) as the substrate. The present work not only characterizes the GT responsible for the 7-O-glycosylation in the biosynthesis of icariin in Epimedium plants, but also indicates the significant potential of an enzymatic approach for the production of glycosylated baohuoside derivatives with different sugar moieties. What's more, these findings also provide a promising alternative for producing natural/unnatural bioactive flavonoid glycosides by metabolic engineering.
Isolation and antioxidant activity of galloyl flavonol glycosides from the seashore plant, Pemphis acidula.
Masuda,Iritani,Yonemori,Oyama,Takeda
, p. 1302 - 1309 (2001)
Four kinds of galloyl flavonol glycosides were found in the leaf extract of Pemphis acidula, a plant growing on the subtropical seashore. Their chemical structures were elucidated to be quercetin or kaempferol 6 -O-galloyl-beta-D-glycosides by using spectroscopic and chemical analyses. One of the flavonols, kaempferol-3-O-(6-O-galloyl-beta-D-galactopyranoside), was newly isolated from natural sources and its structure was completely determined in this investigation. The antioxidant-related activities of the galloyl flavonoids were examined by the DPPH antiradical activity, inhibition of methyl linoleate oxidation, and inhibition of oxidative cell death. These results were compared with those of the corresponding non-galloylated flavonol glycosides and their aglycones. The galloyl flavonoids showed more efficient activity than that of the corresponding flavonol glycosides, but not more than that of the corresponding aglycones in the three assays applied.
Kaempferol and its glycosides from Equisetum silvaticum L. from the khanty-mansi autonomous area
Bonacheva,Botirov, E. Kh.
, p. 777 - 780 (2015/01/30)
Three flavonoids were isolated from the aerial part of the wood horsetail (Equisetum silvaticum L.); two of them were found for the first time. The compounds were identified as kaempferol, kaempferol 3-O-β-D-galactopyranosyl-7-O-α-L-rhamnopyranoside and kaempferol 3-O-rutinosyl-7-O-L-rhamnopyranoside on the basis of the chemical transformations and IR, UV, 1H-NMR and mass spectra.
