- Total Synthesis of (+)-Vicenin-2
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The bis-C-glucosyl flavonoid vicenin-2 (1) has been synthesized by exploiting bis-C-glycosylation of 1,3,5-trifluorobenzene and aromatic nucleophilic substitution to transform fluorine atoms to oxygen functions in excellent yield.
- Ho, Thanh C.,Kamimura, Haruki,Ohmori, Ken,Suzuki, Keisuke
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supporting information
p. 4488 - 4490
(2016/09/28)
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- Beta vulgaris subspecies cicla var. flavescens (Swiss chard): Flavonoids, hepatoprotective and hypolipidemic activities
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The novel flavonoids, 2″,2″′-di-O-α-rhamnopyranosyl-vicenin II, a di-C-glycosyl flavone, and herbacetin 3-O-β-xylopyranosyl- (1″′→2″)-O-β-glucopyranoside, were isolated from the leaves of Beta vulgaris subspecies cicla L. var. flavescens, an edible plant which is consumed in the Mediterranean areas, additional to the known flavonoids, 6-C-glucosyl isoscutellarein, vitexin-(1″′→2″)-O-β-xylopyranosyl, vitexin-(1″′→2″)-O-α-rhamnopyranosyl and vitexin. All metabolites were established by conventional methods of analysis and their structures were confirmed by spectroscopic analysis, including 1D and 2D-NMR and by HR-ESIMS, as well. The extract of the plant leaves shows hepatoprotective effects in rats intoxicated by administration of acetaminophen and exhibits hypolipidemic activity in rats with high-fat-diet induced hypercholesterolemia. The evaluation was done through measuring the liver function enzymes (aspartate and alanine aminotransferases and alkaline phosphatase, the lipid profile (total cholesterol, high density lipoprotein cholesterol, low density lipoprotein cholesterol and triglycerides) and histopathological analysis of liver slides.
- Hashem,Soliman,Hamed,Swilam,Lindequist,Nawwar
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p. 227 - 232
(2016/06/01)
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- New flavone-di-C-glycosides from the seeds of Egyptian lupin (Lupinus termis)
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Raw lupin seeds flour is increasingly used as a food ingredient because of its nutritional and functional values. This study is considered to be the first phytochemical investigation of the flavonoids of the methanol (MeOH) fraction of Lupinus termis seeds. The study led to the isolation of two new di-C-glycoside flavones, apigenin-6-C-β-d-glucopyranosyl-8-C-[β-d-apiofuranosyl-(1 → 2)]-β-glucopyranoside (1), apigenin-6-C-β-d-glucopyranosyl-8-C- [α-l-rhamnopyranosyl-(1 → 2)]-β-glucopyranoside (2), together with one known flavone di-C-glycoside, apigenin-7-O-β-d-apiofuranosyl-6,8- di-C-β-glucopyranoside (3). These compounds are considered to have potential functional properties. The isolated compounds may contribute to the yellow color of raw lupin seeds flour-based products. It may also be used as natural yellow color in food or pharmaceutical products and as a dietary supplement product. These rare flavones were purified by using semi-preparative HPLC. The structures of the isolated compounds were elucidated on the basis of extensive spectroscopic methods, 1D and 2D nuclear magnetic resonance techniques, FAB (Fast Atom Bombardment) - mass spectrometry and acid hydrolysis.
- Elbandy, Mohamed,Rho, Jung-Rae
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p. 127 - 131
(2014/06/23)
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- Total synthesis of three naturally occurring 6,8-di-C-glycosylflavonoids: phloretin, naringenin, and apigenin bis-C-β-d-glucosides
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Three naturally occurring di-C-glycosylflavonoids, phloretin (dihydrochalcone), naringenin (flavanone), and apigenin (flavone) bis-6,8-C-β-d-glucopyranosides (4, 5, and 6), were synthesized in total yields of 52.3%, 53.5%, and 36.4%, respectively, starting from the key compound, di-C-β-d-glucopyranosylphloroacetophenone (1). Benzyl protection of the phenolic hydroxyls in 1 and a subsequent aldol condensation with benzyloxybenzaldehyde led to the production of chalcone 3, which, after hydrogenolysis or acid hydrolysis and deprotection, gave 4 and 5, respectively. The acetylation of 5, followed by DDQ oxidation and deprotection, gave 6.
- Sato, Shingo,Akiya, Toshiki,Nishizawa, Hiroaki,Suzuki, Toshiyuki
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p. 964 - 970
(2007/10/03)
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- Unusual phenolic glycosides from Cotoneaster orbicularis
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The whole plant of Cotoneaster orbicularis contains the novel di-C- glycosylflavone, 4'',4'''-di-O-β-glucopyranosyl-vicenin II, or 6,8-di-C-β- Cellobiosylapigenin, as well as the hitherto unknown natural phenolic glucoside, gentisic acid 2-O-β-glucopyranoside, or orbicularin. Further phenolics are protocatechuic, anisic, caffeic, p-coumaric acids, catechin, epicatechin, 2''-O-α-rhamnopyranosylvitexin, vitexin, rutin, isoquercetrin, hyperin and naringenin. All structures were determined by routine methods of analysis and confirmed mostly by 1H- and 13C-NMR. (C) 2000 Elsevier Science Ltd.
- El-Mousallamy, Amani M.D.,Hussein, Sahar A.M.,Merfort, Irmgard,Nawwar, Mahmoud A.M.
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p. 699 - 704
(2007/10/03)
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- Flavonoids from Ephedra aphylla
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A new di-C-glucosylflavone, 2',2'-di-O-β-glucopyranosyl-vicenin II and a new flavonol di-O-glycoside, herbacetin 3-O-α-rhamnopyranoside-8-O-β- glucopyranoside, were isolated from the aerial parts of Ephedra aphylla. Vicenin II, the 7-methoxy-4-quinolone 2-carboxylic acid, ephedralone, p- hydroxybenzoic, p-coumaric, protocatechuic acids and herbacetin 7-methyl ether were also isolated. The 13C NMR spectrum of the latter compound has been assigned for the first time.
- Hussein, Sahar A.M.,Barakat, Heba H.,Nawar, Mahmoud A.M.,Willuhn, Guenter
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p. 1529 - 1532
(2007/10/03)
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