- Identification of a flavonoid 7-O-glucosyltransferase from Andrographis paniculata
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Andrographis paniculata is an important traditional medicinal herb in which flavonoids are part of the primary specialized metabolites. A flavonoid glucosyltransferase with broad substrate spectrum (named ApUGT3) was successfully identified by screening homologous glycosyltransferase genes from A. paniculata. The enzyme displayed glycosylation activity toward multiple flavonoids in?vitro, and the major products were identified as 7-O-glucosides. Phylogenetic analysis revealed that ApUGT3 is the first reported glycosyltransferase from the Acanthaceae family that belongs to cluster I, suggesting that ApUGT3 is a new flavonoid glycosyltransferase of this subcluster. This enzyme is potentially useful as powerful glycosylation catalysts to modify flavonoid-like compounds and improve their biological activities. (Figure presented.).
- Li, Yuan,Gao, Wei,Huang, Lu-Qi
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p. 279 - 286
(2019/11/21)
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- Synthesis of β-maltooligosaccharides of glycitein and daidzein and their anti-oxidant and anti-allergic activities
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The production of β-maltooligosaccharides of glycitein and daidzein using Lactobacillus delbrueckii and cyclodextrin glucanotransferase (CGTase) as biocatalysts was investigated. The cells of L. delbrueckii glucosylated glycitein and daidzein to give their corresponding 4′- and 7-O-β-glucosides. The β-glucosides of glycitein and daidzein were converted into the corresponding β-maltooligosides by CGTase. The 7-O-β- glucosides of glycitein and daidzein and 7-O-β-maltoside of glycitein showed inhibitory effects on IgE antibody production. On the other hand, β-glucosides of glycitein and daidzein exerted 2,2-diphenyl-1- picrylhydrazyl (DPPH) free-radical scavenging activity and supeoxide-radical scavenging activity.
- Shimoda, Kei,Hamada, Hiroki
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experimental part
p. 5153 - 5161
(2011/02/21)
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- An efficient method for the glycosylation of isoflavones
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The isoflavone phytoestrogens are still of current interest for their positive and negative health benefits. However, there are still many unanswered questions regarding their absorption, metabolism and bioavailability. Studies in this area require access to samples of both the isoflavone 7-O-glucosides, the form found in plants and the 7-O-glucuronides, which are important mammaliam metabolites. A new efficient, high-yielding glycosylation procedure is described for isoflavones, which employs 2,2,2-trifluoro-N-(p-methoxyphenyl) acetamidates as the glycosyl donors. This methodology was used to prepare the 7-O-glycosides of the three main isoflavones, daidzein, genistein and glycitein. The isoflavones were protected with hexanoyl groups which improved their solubility in organic solvents and improved the efficiency of the reaction. The same methodology was then adapted for the synthesis of the analogous 7-O-glucuronides. The new synthesis will provide access to large quantities of these compounds for further biological studies. Wiley-VCH Verlag GmbH & Co. KGaA, 2008.
- Al-Maharik, Nawaf,Botting, Nigel P.
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experimental part
p. 5622 - 5629
(2009/05/27)
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- METHOD FOR PURIFYING AND SEPARATING SOY ISOFLAVONES
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A method for purifying isoflavones glycosides of genistin and daidzin from impurities present in a soy isoflavones concentrate. The method includes digesting a soy isoflavones concentrate with an acidic solution and separating insoluble solids from the acidic solution, wherein the solids are enriched in genistin and comprise glycosides of genistin and daidzin.
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- Synthesis of 4′,7-dihydroxy-6-methoxyisoflavone 7-O-β-D-glucopyranoside (glycitin)
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The aglycone glycitein (1) of the title glucoside glycitin (2) was prepared by oxidative rearrangement of the fully protected chalcone 4 by Tl(NO3)3 in MeOH into 5 followed by deprotection and ring closure. Its glucosylation with α-acetobromoglucose and subsequent saponification gave 2 as the main product. VCH Verlagsgesellschaft mbH, 1996.
- Nogradi, Mihaly,Szoellosy, Aron
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p. 1651 - 1652
(2007/10/03)
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