- Reactions of genistein with alkylperoxyl radicals
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Antioxidant actions of the soy isoflavone genistein are believed to contribute to its overall chemopreventive activity. However, the mechanisms of its antioxidant reactions remain unknown. The objective of this study was to characterize the reaction products of genistein (5,7,4'- trihydroxyisoflavone) with peroxyl radicals generated by thermolysis of 2,2'- azobis(2,4-dimethylvaleronitrile) (AMVN). Genistein oxidations with AMVN- derived peroxyl radicals yielded orobol (5,7,3',4'-tetrahydroxyisoflavone), a hydroxylated derivative of genistein, and several stable adducts of 4'- oxogenistein with AMVN-derived radicals. Some of these adducts include novel structures resulting from secondary oxidations of the AMVN-derived moiety. For all the observed oxidation products, the modifications occurred on the B- ring of the molecule. Genistein oxidation product structures provide potentially useful markers of genistein antioxidant chemistry.
- Arora, Arti,Valcic, Susanne,Cornejo, Santiago,Nair, Muralee G.,Timmermann, Barbara N.,Liebler, Daniel C.
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- Orobol: An Isoflavone Exhibiting Regulatory Multifunctionality against Four Pathological Features of Alzheimer's Disease
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We report orobol as a multifunctional isoflavone with the ability to (i) modulate the aggregation pathways of both metal-free and metal-bound amyloid-β, (ii) interact with metal ions, (iii) scavenge free radicals, and (iv) inhibit the activity of acetylcholinesterase. Such a framework with multifunctionality could be useful for developing chemical reagents to advance our understanding of multifaceted pathologies of neurodegenerative disorders, including Alzheimer's disease.
- Nam, Geewoo,Ji, Yonghwan,Lee, Hyuck Jin,Kang, Juhye,Yi, Yelim,Kim, Mingeun,Lin, Yuxi,Lee, Young-Ho,Lim, Mi Hee
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- Metabolism of genistein by rat and human cytochrome P450s
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The metabolism of genistein (4',5,7-trihydroxyisoflavone), a phytoestrogen derived from soy products, was investigated using rat and human liver microsomes and recombinant human cytochrome P450 enzymes. Metabolism of genistein by microsomes obtained from rats treated with pyridine, phenobarbital, β-naphthoflavone, isosafrole, pregnenolone-16α-carbonitrile, or 3-methylcholanthrene resulted in very different product profiles consisting of five different NADPH- and time-dependent metabolites as observed by HPLC reverse-phase analysis at 260 nm. The metabolism of genistein was also investigated with recombinant human cytochrome P450 1A1, 1A2, 1B1, 2B6, 2C8, 2E1, or 3A4. P450s 1A1, 1A2, 1B1, and 2E1 metabolized genistein to form predominantly one product (peak 3) with smaller amounts of peaks 1 and 2. P450 3A4 produced two different products (peaks 4 and 5). Product peaks 1-3 eluted off the HPLC column prior to the parent compound genistein, and the UV/vis spectra, GC/MS, and ESI/MS/MS analyses support the conclusion that these products result from hydroxylation of genistein. The product peak 3 has been identified by tandem mass spectrometry as 3',4',5,7- tetrahydroxyisoflavone, also known as orobol, and peaks 1 and 2 appear to be hydroxylated at position 6 or 8.
- Roberts-Kirchhoff, Elizabeth S.,Crowley, Jan R.,Hollenberg, Paul F.,Kim, Hyesook
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- Comparative phytochemical analysis of four Mexican Nymphaea species
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Four Mexican Nymphaea species, N. ampla, N. pulchella, N. gracilis and N. elegans belonging to subgenera Brachyceras were analyzed. In this work two 5-glycosyl isoflavones, 7,3′,4′-trihydroxy-5-O-β-d-(2″- acetyl)-xylopyranosylisoflavone (1) and 7,3′,4′-trihydroxy-5-O- α-l-rhamnopyranosylisoflavone (2), were isolated from N. ampla and N. pulchella, respectively, together with other known 3-glycosyl flavones and triterpene saponins from the same four species. The structures were elucidated by 1D and 2D NMR, FABMS, and other spectroscopic analyses. These results confirmed that the four species were different from each other and established that N. pulchella represents a different taxa than N. ampla. In addition, the 5-glycosyl isoflavones could be considered as a taxonomic character of this group of plants.
- Marquina, Silvia,Bonilla-Barbosa, Jaime,Alvarez, Laura
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- Identification of ortho catechol-containing isoflavone as a privileged scaffold that directly prevents the aggregation of both amyloid β plaques and tau-mediated neurofibrillary tangles and its in vivo evaluation
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In this study, polyhydroxyisoflavones that directly prevent the aggregation of both amyloid β (Aβ) and tau were expediently synthesized via divergent Pd(0)-catalyzed Suzuki-Miyaura coupling and then biologically evaluated. By preliminary structure–activity relationship studies using thioflavin T (ThT) assays, an ortho-catechol containing isoflavone scaffold was proven to be crucial for preventing both Aβ aggregation and tau-mediated neurofibrillary tangle formation. Additional TEM experiment confirmed that ortho-catechol containing isoflavone 4d significantly prevented the aggregation of both Aβ and tau. To investigate the mode of action (MOA) of 4d, which possesses an ortho-catechol moiety, 1H-15N HSQC NMR analysis was thoroughly performed and the result indicated that 4d could directly inhibit both the formation of Aβ42 fibrils and the formation of tau-derived neurofibrils, probably through the catechol-mediated nucleation of tau. Finally, 4d was demonstrated to alleviate cognitive impairment and pathologies related to Alzheimer's disease in a 5XFAD transgenic mouse model.
- Do, Ji Min,Gee, Min Sung,Inn, Kyung-Soo,Kim, Jong-Ho,Kim, Nam Kwon,Kim, Nam-Jung,Lee, Hyun Woo,Lee, Jong Kil,Seo, Min-Duk,Seong, Ji Hye,Son, Seung Hwan,Yoo, Hyung-Seok,Yoo, Ji-Na
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- Phenolic constituents from the twigs of Betula schmidtii collected in Goesan, Korea
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Six undescribed phenolic derivatives along with thirty two known compounds were isolated from the twigs of Betula schmidtii. The chemical structures were characterized through extensive spectroscopic analysis and chemical methods. All known compounds were first isolated in this plant. The anti-inflammatory effect of the isolates was tested by measuring nitric oxide production in lipopolysaccharide-activated BV-2 cells. Isotachioside, 4-allyl-2-hydrophenyl 1-O-β-D-apiosyl-(1 → 6)-β-D-glucopyranoside, genistein 5-O-β-D-glucoside, and prunetinoside showed a slight potency to lower the NO production against LPS-activated microglia with IC50 values of 23.9, 25.3, 28.8, and 34.0 μM, respectively.
- Park, Kyoung Jin,Cha, Joon Min,Subedi, Lalita,Kim, Sun Yeou,Lee, Kang Ro
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- Production and anti-melanoma activity of methoxyisoflavones from the biotransformation of genistein by two recombinant Escherichia coli strains
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Biotransformation of the soy isoflavone genistein by sequential 3′-hydroxylation using recombinant Escherichia coli expressing tyrosinase from Bacillus megaterium and then methylation using another recombinant E. coli expressing O-methyltransferase from S
- Chiang, Chien-Min,Chang, Yu-Jhe,Wu, Jiumn-Yih,Chang, Te-Sheng
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- CATECHOL DERIVATIVES PREPARED BY USING TYROSINASE, METHOD FOR PREPARATION THEREOF, AND APPLICATION THEREOF
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The present invention refers to using tyrosinase and pyrocatechole type structural material technology and exclusively on the basis of the response in the biosynthesis of, melanocyte secondary oxidation reaction by effectively inhibiting, mono phenol type primary structural material optionally catalyst only complex induced a are defined.. The present invention refers to using the same variety of functional pyrocatechole type materials, with high productivity and. there is provided a technique for production yield. (by machine translation)
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Paragraph 0084
(2016/12/12)
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- A Versatile Microbial System for Biosynthesis of Novel Polyphenols with Altered Estrogen Receptor Binding Activity
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Isoflavonoids possess enormous potential for human health with potential impact on heart disease and cancer, and some display striking affinities for steroid receptors. Synthesized primarily by legumes, isoflavonoids are present in low and variable abundance within complex mixtures, complicating efforts to assess their clinical potential. To satisfy the need for controlled, efficient, and flexible biosynthesis of isoflavonoids, a three-enzyme system has been constructed in yeast that can convert natural and synthetic flavanones into their corresponding isoflavones in practical quantities. Based on the determination of the substrate requirements of isoflavone synthase, a series of natural and nonnatural isoflavones were prepared and their binding affinities for the human estrogen receptors (ERα and ERβ) were determined. Structure activity relationships are suggested based on changes to binding affinities related to small variations on the isoflavone structure.
- Chemler, Joseph A.,Lim, Chin Giaw,Daiss, John L.,Koffas, Mattheos A.G.
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experimental part
p. 392 - 401
(2011/06/28)
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- Syntheses of Isoflavones and Isoflavone Glycosides, and Their Inhibitory Activity against Bovine Liver &β-Galactosidase
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To clarify the relationship between the structure and inhibitory action toward β-D-galactosidase (EC 3.2.1.21) of isoflavones and isoflavone glycosides, a number of polyhydroxyisoflavones, and the α-L-rhamnosides and β-L-quinovosides of daidzein and genistein were synthesized.Among the polyhydroxyisoflavones, 2',3',4',7-tetrahydroxyisoflavone showed the strongest inhibitory activity (Ki = 26 * 10-6 M).Among the glycosides, all the L-rhamnosides were strong inhibitors, of which genistein 4',7-di-O-α-L-rhamnoside was the strongest (Ki = 4.44 * 10-6 M), while all the isoflavone β-L-quinovosides were considerably weak or possessed no inhibition.
- Nishiyama, Kiyotoshi,Esaki, Sachiko,Deguchi, Ikuko,Sugiyama, Naoko,Kamiya, Shintaro
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p. 107 - 114
(2007/10/02)
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- THE FIRST IDENTIFICATION OF ISOFLAVONES FROM A BRYOPHYTE
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Bryum capillare is shown to accumulate the isoflavones orobol and pratensein as the 7-O-glucosides and predominantly, as the 7-(6''-malonylglucosides).This is the first finding of isoflavonoids in bryophytes.The phylogenetic relevance of this observation is briefly discussed.Key Word Index - Bryum capillare; Bryales; Musci; moss; isoflavones; orobol; pratensein; 7-O-glucosides; 6''-malonyl glucosides; NMR spectra.
- Anhut, Siegbert,Zinsmeister, H. Dietmar,Mues, Ruediger,Barz, Wolfgang,Mackenbrock, Klaus,et al.
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p. 1073 - 1076
(2007/10/02)
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- Synthesis of the Pyranoisoflavonoid, Heminitidulan. Isoflavanoid and Rotenoid Glycosides from the Bark of Dalbergia nitidula Welw. ex Bak.
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Synthesis of racemates of the complex pyranoisoflavan, (3S)-heminitidulan, a metabolite from the bark of Dalbergia nitidula, is accomplished.The isoflavone C-glycoside pairs 8-C-β-D-glucopyranosyl- and 6,8-di-C-β-glucopyranosyl-genistein and -orobol and the associated rotenoid glycoside (5'R,6aR,12aR)-8'-O-β-D-glucopyranosyl-12a-hydroxyamorphigenin comprise the predominant isoflavonoids in the same source. 13C N.m.r. spectra of the glycosides are recorded.
- Heerden, Fanie R. van,Brandt, E. Vincent,Roux, David G.
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p. 2463 - 2469
(2007/10/02)
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