- Synthesis and Biological Evaluation of 4-Substituted Kaempfer-3-ols
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The synthesis of two series of five kaempfer-3-ols was described. The first set all have a C-3 hydroxyl group and the second has a carboxymethoxy ether at the C-3 position. Both series have variable substitution at the C-4 position (i.e., OH, Cl, F, H, OMe). Both kaempferols and carboxymethoxy ethers were evaluated for their ability to inhibit ribosomal s6 kinase (RSK) activity and cancer cell proliferation.
- Kim, Sugyeom,Lannigan, Deborah A.,Li, Yu,Lin, Lin,O'Doherty, George A.,Sayasith, Peyton R.,Tarr, Ariel T.,Wright, Eric B.,Yasmin, Sharia
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p. 4279 - 4288
(2020/04/09)
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- Biosynthesis of natural and novel C-glycosylflavones utilising recombinant Oryza sativa C-glycosyltransferase (OsCGT) and Desmodium incanum root proteins
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The rice C-glycosyltransferase (OsCGT) is one of only a small number of characterised plant C-glycosyltransferases (CGT) known. The enzyme C-glucosylates a 2-hydroxyflavanone substrate with UDP-glucose as the sugar donor to produce C-glucosyl-2-hydroxyflavanones. We tested substrate specificity of the enzyme, using synthetic 2-hydroxyflavanones, and showed it has the potential to generate known natural CGFs that have been isolated from rice and also other plants. In addition, we synthesised novel, unnatural 2-hydroxyflavanone substrates to test the B-ring chemical space of substrate accepted by the OsCGT and demonstrated the OsCGT capacity as a synthetic reagent to generate significant quantities of known and novel CGFs. Many B-ring analogues are tolerated within a confined steric limit. Finally the OsCGT was used to generate novel mono-C-glucosyl-2-hydroxyflavanones as putative biosynthetic intermediates to examine the potential of Desmodium incanum biosynthetic CGTs to produce novel di-C-glycosylflavones, compounds implicated in the allelopathic biological activity of Desmodium against parasitic weeds from the Striga genus.
- Hao,Caulfield,Hamilton,Pickett,Midega,Khan,Wang,Hooper
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- Isotopic labelling of quercetin 3-glucoside
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The potentially important dietary antioxidant, quercetin 3-O-β-d-glucoside, has been 13C-labelled at C-2 of the flavonoid unit by synthesis in 15% yield over five steps from [13C]carbon dioxide. The route is appropriate for radiochemical synthesis. Formation of the protected 3-glucosylated flavonol appears to result from [1,7]-sigmatropic rearrangement with migration of a benzyl group followed by cyclisation. A free 5-OH results even when a phosphazene superbase is used.
- Caldwell, Stuart T.,Petersson, Hanna M.,Farrugia, Louis J.,Mullen, William,Crozier, Alan,Hartley, Richard C.
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p. 7257 - 7265
(2007/10/03)
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