- Anomeric selectivity in the synthesis of galloyl esters of d-glucose
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The anomeric selectivity of the ester formation between d-glucopyranose and gallic acid was investigated under a variety of conditions. A new protocol was established that allows performing the reaction under conditions where mutarotation is very slow. Hi
- Binkley, Robert C.,Ziepfel, Jessica C.,Himmeldirk, Klaus B.
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- Synthesis and antitumor activity of ellagic acid peracetate
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Ellagic acid (1) was synthesized for the first time from methyl gallate through α-pentagalloylglucose (α-PGG), and ellagic acid peracetate (3,4,3′,4′-tetra-O-acetylellagic acid, 2) was derived from 1 by acetylation. Oral administration of 2 suppressed melanoma growth significantly in C7BL/6 immunocompetent mice without having any effect on natural killer (NK) cell activity. Comparison of the immunoenhancing activities of 1 and 2 indicated that the latter compound increased white blood cell quantities in peripheral blood and immune cells enriched from the bone marrow and liver of mice. Therefore, both the antitumor efficacy and the immunity enhancement by 2 were greater than those by 1. In addition, on oral administration, neither 1 nor 2 resulted in whole body, liver, or spleen weight changes of normal, tumor-free mice, indicating that these compounds are potentially nontoxic to mice. It was shown that ellagic acid peracetate (2) inhibits B16 melanoma cell growth in vitro and induces B16 cell apoptosis, corresponding to BCL-2 down-regulation. Collectively, the present data imply that 2 can suppress tumor growth by enhancing mouse immunity and inducing tumor cell apoptosis without apparent side effects.
- Ren, Yulin,Still, Patrick C.,Kinghorn, A. Douglas,Wei, Min,Chen, Xiaozhuo,Himmeldirk, Klaus,Yuan, Shunzong,Deng, Youcai,Yu, Jianhua
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- Efficient total synthesis of the natural products 2,3,4,6-tetra-O-galloyl-D-glucopyranose, 1,2,3,4,6-penta-O-galloyl-β-D-glucopyranose and the unnatural 1,2,3,4,6-penta-O-galloyl-α-D-glucopyranose
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A short synthesis of the natural products 2,3,4,6-tetra-O-galloyl-D-glucopyranose (8), 1,2,3,4,6-penta-O-galloyl-β-D-glucopyranose (10) and the unnatural 1,2,3,4,6-penta-O-galloyl-α-D-glucopyranose (13) was achieved based on a efficient esterification reaction of the benzylated gallic acid 5 with the α,β-glucopyranoses 11 and 4, respectively.
- Khanbabaee, Karamali,Loetzerich, Kerstin
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- Plasminogen activator inhibitor-1 inhibitors and methods of use thereof to modulate lipid metabolism
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The invention relates to plasminogen activator-1 (PAI-1) inhibitor compounds and uses thereof in the treatment of any disease or condition associated with elevated PAI-1. The invention includes, but is not limited to, the use of such compounds to modulate lipid metabolism and treat conditions associated with elevated PAI-1, cholesterol, or lipid levels.
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Page/Page column 60; 61
(2015/09/22)
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- Gallotannins and Tannic Acid: First Chemical Syntheses and in Vitro Inhibitory Activity on Alzheimer's Amyloid β-Peptide Aggregation
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The screening of natural products in the search for new lead compounds against Alzheimer's disease has unveiled several plant polyphenols that are capable of inhibiting the formation of toxic β-amyloid fibrils. Gallic acid based gallotannins are among these polyphenols, but their antifibrillogenic activity has thus far been examined using "tannic acid", a commercial mixture of gallotannins and other galloylated glucopyranoses. The first total syntheses of two true gallotannins, a hexagalloylglucopyranose and a decagalloylated compound whose structure is commonly used to depict "tannic acid", are now described. These depsidic gallotannins and simpler galloylated glucose derivatives all inhibit amyloid β-peptide (Aβ) aggregation invitro, and monogalloylated α-glucogallin and a natural β-hexagalloylglucose are shown to be the strongest inhibitors.
- Sylla, Tahiri,Pouységu, Laurent,Dacosta, Grégory,Deffieux, Denis,Monti, Jean-Pierre,Quideau, Stéphane
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supporting information
p. 8217 - 8221
(2015/07/07)
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- Designing allosteric inhibitors of factor XIa. Lessons from the interactions of sulfated pentagalloylglucopyranosides
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We recently introduced sulfated pentagalloylglucopyranoside (SPGG) as an allosteric inhibitor of factor XIa (FXIa) (Al-Horani et al., J. Med Chem. 2013, 56, 867-878). To better understand the SPGG-FXIa interaction, we utilized eight SPGG variants and a range of biochemical techniques. The results reveal that SPGG's sulfation level moderately affected FXIa inhibition potency and selectivity over thrombin and factor Xa. Variation in the anomeric configuration did not affect potency. Interestingly, zymogen factor XI bound SPGG with high affinity, suggesting its possible use as an antidote. Acrylamide quenching experiments suggested that SPGG induced significant conformational changes in the active site of FXIa. Inhibition studies in the presence of heparin showed marginal competition with highly sulfated SPGG variants but robust competition with less sulfated variants. Resolution of energetic contributions revealed that nonionic forces contribute nearly 87% of binding energy suggesting a strong possibility of specific interaction. Overall, the results indicate that SPGG may recognize more than one anion-binding, allosteric site on FXIa. An SPGG molecule containing approximately 10 sulfate groups on positions 2 through 6 of the pentagalloylglucopyranosyl scaffold may be the optimal FXIa inhibitor for further preclinical studies.
- Al-Horani, Rami A.,Desai, Umesh R.
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supporting information
p. 4805 - 4818
(2014/07/07)
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- Plasminogen Activator Inhibitor-1 Inhibitors And Methods Of Use Thereof To Modulate Lipid Metabolism
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The invention relates to plasminogen activator-1 (PAI-1) inhibitor compounds and uses thereof in the treatment of any disease or condition associated with elevated PAI-1. The invention includes, but is not limited to, the use of such compounds to modulate lipid metabolism and treat conditions associated with elevated PAI-1, cholesterol, or lipid levels.
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- Synthesis and structure-activity relationship study of antidiabetic penta-O-galloyl-D-glucopyranose and its analogues
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The rapid increase of obesity-associated diabetes has created urgent demands for more effective antidiabetic therapies and pharmaceuticals that are able to address the problems of hyperglycemia and weight gain simultaneously. Our previous studies indicated that the α- and β-anomers of penta-O-galloyl-D-glucopyranose (PGG), 2 and 3, act as insulin mimetics that bind to and activate the insulin receptor, stimulate glucose transport in adipocytes, and reduce blood glucose and insulin levels in diabetic and obese animals. In addition, they inhibit differentiation of preadipocytes into adipocytes. These activities suggest that 2 and 3 may reduce blood glucose without increasing adiposity. To investigate the structure-activity relationship of 2 and 3, four series of novel compounds were prepared and their glucose transport stimulatory activities were measured using a radioactive glucose uptake bioassay. The assay results indicate that both the glucose and the galloyl groups are critical to the activity of 2 and 3. It appears that the glucose core provides an optimal scaffold to present the galloyl groups with the correct spatial orientation to induce activity. Moreover, the galloyl groups linked to the 1, 2, 3, and 4 positions of glucose are essential, while the galloyl group connected to the 6 position of 2 is unnecessary for the induction of activity. The discovery that two related novel compounds, 6-deoxytetra-O-galloyl-α-D-glucopyranose (43) and tetra-O-galloyl-α- D-xylopyranose (59), also possess glucose transport stimulatory activity suggests that 2 may be further modified around position 6 to modulate and enhance its efficacy. To test this hypothesis, we developed a new synthetic method that allows for the stereoselective preparation of derivatives of 2 that are modified on C-6. We found that 6-chloro-6-deoxy-1,2,3,4-tetra-O-galloyl- α-D-glucopyranose (80) exhibits a significantly higher glucose transport stimulatory activity than 2. Its activity is comparable to that of insulin.
- Ren, Yulin,Himmeldirk, Klaus,Chen, Xiaozhuo
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p. 2829 - 2837
(2007/10/03)
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- AN EFFICIENT METHOD TO SYNTHESIZE BENZYL GROUP-PROTECTED ALPHA-PENTAGALLOYLGLUCOSE (Α-PGG) AND ITS ANALOGUES
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A method to synthesize benzyl group protected alpha-pentagalloylglucose (α-PGG) and related compounds. The method comprises the steps of: suspending a highly reactive acylation agent and an acylating catalyst in a donor solvent; adding α-D-glucose or an analogue thereof to the mixture; reacting the mixture at room temperature for a time sufficient for reaction to occur; evaporating the solvent; taking up the residue in an appropriate solvent; filtering the residue and solvent mixture; and evaporating off the solvent.
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Page/Page column 5
(2008/06/13)
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- Improved anomeric selectivity for the aroylation of sugars
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By manipulating the solvent and using bulky TMEDA as a base, good yields and improved anomeric selectivities were obtained for the aroylation of D-glucose over similar esterifications using pyridine. The reaction has been extended to mannose and the β-ano
- Barros, M. Teresa,Maycock, Christopher D.,Rodrigues, Paula,Thomassigny, Christine
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p. 1373 - 1376
(2007/10/03)
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- Ellagitannin chemistry. Evolution of a three-component coupling strategy for the synthesis of the dimeric ellagitannin coriariin A and a dimeric gallotannin analogue
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The total synthesis of the dimeric ellagitannin coriariin A is reported. The key reaction to access the dimeric framework was realized early in the synthesis pathway via a bis acylation reaction of a dehydrodigalloyl diacid with 2 equiv of a glucopyranose
- Feldman,Lawlor,Sahasrabudhe
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p. 8011 - 8019
(2007/10/03)
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