- COMPOSITION FOR ENHANCING SKIN ELASTICITY OR IMPROVING SKIN WRINKLES COMPRISING HEPTAHYDROXYFLAVAN AS AN EFFECTIVE INGREDIENT
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Heptahydroxyflavan or a salt, isomer, hydrate or solvate thereof, which is an active ingredient of the present disclosure, can enhance skin elasticity and improve skin wrinkles by inhibiting the activity of MMP-1. In addition, the heptahydroxyflavan or a salt, isomer, hydrate or solvate thereof, which is an active ingredient of the present disclosure, can be used in various compositions such as cosmetics, health functional foods, etc. because it is safe with no cytotoxicity.
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Paragraph 0045
(2021/01/26)
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- Total Synthesis of the Natural Products Ulmoside A and (2 R,3 R)-Taxifolin-6- C -β- d -glucopyranoside
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An efficient first total synthesis of highly polar ulmoside A and (2 R,3 R)-taxifolin-6- C -β- d -glucopyranoside, useful for the prevention of metabolic disorders, has been described. Key elements of the synthesis include a Sc(OTf) 3-catalyzed regio- and stereoselective C -glycosidation on taxifolin in 35percent yield with d -glucose and chiral semipreparative reverse-phase high-performance liquid chromatography (HPLC) for the separation of both taxifolins and the diastereomeric mixture of taxifolin-6- C -β- d -glucopyranosides. Correlation of the analytical data of synthetic ulmoside A and its diastereomer with a natural ulmoside A sample confirmed the assigned absolute stereochemistry of the natural products.
- Batchu, Venkateswara Rao,Dorigundla, Aravind Reddy,Gurrapu, Raju,Macha, Lingamurthy,Vanka, Umamaheswara Sarma
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supporting information
p. 1097 - 1101
(2020/07/03)
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- NOVEL APPROACH FOR SYNTHESIS OF CATECHINS
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A process for synthesis of enatiomerically pure or enatiomerically enriched or racemic mixture of (+and/or?) epicatechin echm and its intermediates, comprising the steps of: (i) obtaining penta-protected quercetin; (ii) reducing the penta-protected quercetin obtained from step (i); (iii) optionally deprotecting the compound of step (ii); (iv) reducing the compound obtained from step (ii) or step (iii) in the presence of a chiral/achiral reducing agent to obtain a chiral intermediate; (v) deprotecting and/or hydrogenation of the chiral intermediate obtained from step (iv) to obtain (?)-epicatechin; (vi) optionally simultaneously deprotecting and by drogenation of the compound obtained from step (ii) to obtain racemic epicatechin.
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Paragraph 0159; 0160; 0161
(2016/01/15)
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- Total synthesis of (-)-bis-8,8′-catechinylmethane isolated from cocoa liquor
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An efficient synthesis of bis-8,8′-catechinylmethane, a dimeric flavanol linked through a methylene bridge, is described. Our strategy involved a regioselective coupling via a trifluoroacetic anhydride condensation reaction followed by ketone reduction to the methylene employing new conditions (lithium aluminum hydride and hexafluorophosphoric acid).
- Pariollaud, Marie,Cockrell, Jennifer,Selenski, Carolyn
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p. 2484 - 2486
(2014/05/06)
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- Procyanidin oligomers. A new method for 4→8 interflavan bond formation using C8-boronic acids and iterative oligomer synthesis through a boron-protection strategy
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Interest in the synthesis of procyanidin (catechin or epicatechin) oligomers that contain the 4→8 interflavan linkage remains high, principally due to research into their health effects. A novel coupling utilising a C8-boronic acid as a directing group was developed in the synthesis of natural procyanidin B3 (i.e., 3,4-trans-(+)-catechin-4α→8-(+)- catechin dimer). The key interflavan bond was forged using a novel Lewis acid-promoted coupling of C4-ether 6 with C8-boronic acid 16 to provide the α-linked dimer with high diastereoselectivity. Through the use of a boron protecting group, the new coupling procedure was extended to the synthesis of a protected procyanidin trimer analogous to natural procyanidin C2.
- Dennis, Eric G.,Jeffery, David W.,Johnston, Martin R.,Perkins, Michael V.,Smith, Paul A.
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experimental part
p. 340 - 348
(2012/01/06)
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- Synthesis and antimicrobial activities of 3-O-alkyl analogues of (+)-catechin: Improvement of stability and proposed action mechanism
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We report here the synthesis and biological properties of 3-O-alkyl analogues of (+)-catechin (5), which itself is one of the major natural polyphenols found in green tea and has several physiological activities. Starting from 5, a series of 3-O-alkyl-(+)-catechin derivatives were investigated as potent antimicrobial agents. The presence of an alkyl chain rather than acyl on 3-O- showed an increase in antimicrobial activity which may be due to stability in standard culture condition. The most promising compound is 8e, 3-O-decyl analogue, with the MIC of 0.5-2, 32-128 and 2-4?μg/mL against Gram-positive bacteria, Gram-negative bacteria and human pathogenic fungi, respectively. Regarding action mechanism, the antimicrobial activity is possibly due to the lipophilicity and disrupting ability of the analogues to the liposome membrane.
- Park, Ki Duk,Cho, Sung Jin
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experimental part
p. 1028 - 1033
(2010/04/24)
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- Hydroxylation of ring A of flavan-3-ols: Influence of the ring A substitution pattern on the oxidative rearrangement of 6-hydroxyflavan-3-ols
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A general procedure for the oxidation of catechin derivatives is described, leading to the introduction of a new hydroxyl group at C-6. This procedure has been used for the synthesis of a number of 6-hydroxy flavan-3-ols, including elephantorrhizol, a natural flavan-3-ol exhibiting a fully substituted A ring. The substitution at C-8, albeit of poor influence on the course of this oxidation reaction, has been demonstrated to be preponderant for the further spontaneous oxidation and rearrangement of 6-hydroxy-flavan-3-ols into p-benzoquinones. The whole procedure allows the preparation of 6-alkyl substituted benzoquinones derived from catechin. Georg Thieme Verlag Stuttgart.
- Boyer, Francois-Didier,Beauhaire, Josiane,Martin, Marie Therese,Ducrot, Paul-Henri
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p. 3250 - 3260
(2008/09/16)
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- Synthesis of modified proanthocyanidins: Introduction of acyl substituents at C-8 of catechin. Selective synthesis of a C-4 → O → C-3 ether-linked procyanidin-like dimer
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The regioselective introduction of substituents at C-8 of (+)-catechin is described, leading to the synthesis of several catechin derivatives with various substitution patterns to be used for the further synthesis of modified proanthocyanidins. Thereafter, a new 3-O-4 ether-linked procyanidin-like derivative was synthesized. Its formation was selectively achieved through TiCl4-catalyzed condensation of 4-(2-hydroxyethoxy)tetra-O-benzyl catechin with the 8-trifluoroacetyl adduct of tetra-O-benzyl catechin.
- Beauhaire, Josiane,Es-Safi, Nour-Eddine,Boyer, Francois-Didier,Kerhoas, Lucien,Le Guerneve, Christine,Ducrot, Paul-Henri
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p. 559 - 562
(2007/10/03)
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- An efficient coversion of catechine into 3,4-trans-leucocyanidin
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Catechine was efficiently converted into 3,4-trans-leococyanidin by seven steps involving an acetoxylation at the benzylic position of catechine pentabenzyl ether, followed by hydrolysis, oxidation, deprotection, and stereoselective reduction, successively.
- Kikuchi, Toyohiko,Nishimura, Masato,Hoshino, Atsushi,Morita, Yasumasa,Iida, Shigeru,Saito, Norio,Honda, Toshio
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p. 1469 - 1475
(2007/10/03)
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