- CONFIRMATION OF STRUCTURE OF THE FLAVONOL GLUCOSIDE TAMBULETIN
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The structure of tambuletin, present in seeds of Xanthoxylum species has been confirmed as the 8-glucoside of gossypetin 7,4'-dimethyl ether. - Key Word Index - Zanthoxylum alatum; Rutaceae; tambuletin; 3,5,3'-trihydroxy-7,4'-dimethoxy-8-O-β-D-glucopyranosylflavone; structure determination.
- Nair, A. G. Ramachandran,Nair, G. Aravindakshan,Joshua, C. P.
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Read Online
- Preparation method and intermediates of flavonoids
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The invention discloses a preparation method and intermediates of flavonoids. The preparation method comprises the following steps: in a solvent, in the presence of an acid, performing a ring-opening reaction and an elimination reaction on a compound 8 to obtain a compound 9. Raw materials used in the method are easy to acquire, and the method has high yields and simple post processes, and does not need column chromatography.
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Paragraph 0252; 0255-0256
(2017/11/16)
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- Preparation method of flavonoids
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The invention discloses a preparation method of flavonoids. The method comprises the following step: in a solvent, in the presence of iodine and a silver salt or in the presence of iodine and a copper salt, performing an iodination reaction on a compound 1 to obtain a compound 2. Raw materials used in the method are easy to acquire, and the method has high yields and simple post processes, and does not need column chromatography.
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Paragraph 0252; 0255; 0256
(2017/11/16)
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- Facile synthesis of norwogonin, isoscutellarein, and herbacetin
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An expeditious synthesis of norwogonin, isoscutellarein, and herbacetin, has been accomplished by a strategy featuring a borylation of sterically hindered aryl iodide and a one-pot oxidation to generate the C-3 and C-8 OH groups. The total synthesis gives excellent yields and conventional flash column chromatography is not needed for purification.
- Yuan, Hu,Ye, Ji,Chen, Hao,Zhao, Zeng,Luo, Xukai,Zhang, Weidong,Sun, Qingyan
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supporting information
p. 3389 - 3391
(2016/07/11)
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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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- Bioactive constituents from chinese natural medicines. XXXII.1 aminopeptidase N and aldose reductase inhibitors from sinocrassula indica: Structures of sinocrassosides B4, B5, C1, and D1-D3
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From the methanolic extract of the whole plant of Sinocrassula indica (Crassulaceae), six new flavonol glycosides, sinocrassosides B4 (1), B5 (2), C1 (3), D1 (4), D2 (5), and D3 (6), were isolated together with 30 compounds. The structures of 1-6 were elucidated on the basis of chemical and physicochemical evidence. In addition, several constituents were found to show inhibitory effects on aminopeptidase N and aldose reductase.
- Morikawa, Toshio,Xie, Haihui,Wang, Tao,Matsuda, Hisashi,Yoshikawa, Masayuki
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experimental part
p. 1438 - 1444
(2009/10/23)
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- Flavonol glucuronides and C-glucosidic ellagitannins from Melaleuca squarrosa
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Two flavonoids and three ellagitannins, squarrosanins A, B, and C, were isolated from the leaves of Melaleuca squarrosa. The flavonoids were characterized structurally as kaempferol-3-O-(2″-O-galloyl)-glucuronide and herbacetin-3-O-glucuronide, while the ellagitannins were characterized as monomeric and dimeric C-glucosidic ellagitannins by application of spectroscopic and chemical methods. The antioxidant effect of the polyphenolic constituents of the M. squarrosa leaves was also examined in vitro, and C-glucosidic tannins including oligomers were shown to be more effective radical scavengers against 1,1-diphenyl-2-picrylhydrazyl (DPPH) than flavonoids and ordinary ellagitannins.
- Yoshimura, Morio,Ito, Hideyuki,Miyashita, Kyoko,Hatano, Tsutomu,Taniguchi, Shoko,Amakura, Yoshiaki,Yoshida, Takashi
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experimental part
p. 3062 - 3069
(2009/04/11)
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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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- FLAVONOID CONSTITUENTS OF EPHEDRA ALATA
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Two new flavonol glucosides have been identified in Ephedra alata, namely, herbacetin 8-methyl ether 3-O-glucoside-7-O-rutinoside and herbacetin 7-O-(6''-quinylglucoside).The known flavonoids vicenin II, lucenin III, kaempferol 3-rhamnoside, quercetin 3-rhamnoside and herbacetin 7-glucoside were also found.The structure of the isolated compounds was determined mostly by FABMS and 1H NMR spectroscopy.The final structure of the new compounds and of herbacetin 7-glucoside was confirmed by 13C NMR soectroscopy. Key Word Index - Ephedra alata; Ephedraceae; herbacetin 8-methyl ether 3-O-glucoside-7-O-rutinoside; herbacetin 7-O-(6''-quinyl glucoside); flavonol O-glycosides and C-glycosylflavones.
- Nawwar, Mahmoud A. M.,El-Sissi, Hassan I.,Barakat, Heba H.
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p. 2937 - 2940
(2007/10/02)
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- Herbacetin-3-β-D-(2-O-β-D-glucopyranosidoglucopyranoside)-8-β-D-glucopyranoside and Gossypetin-3-β-D-(2-O-β-D-glucopyranosidoglucopyranoside)-8-β-D-glucopyranoside, two New Flavonol-glycosides from Equisetum hyemale L. (Equisetaceae)
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Two new flavonol glycosides, herbacetin- and gossypetin-3-β-D-(2-O-β-D-glucopyranosidoglucopyranoside)-8-β-D-glucopyranoside have been isolated from the aerial parts of Equisetum hyemale L. together with the known kaempferol-3-β-D-(2-O-β-D-glucopyranosidoglucopyranoside)-7-β-D-glucopyranoside. - Key words: Equisetum hyemale, Equisetaceae, Herbacetin-glycosides, Gossypetin-glycosides, 13C NMR Spectra
- Geiger, Hans,Reichert, Sven,Markham, Ken R.
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p. 504 - 507
(2007/10/02)
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