Amidine pseudodisaccharides

Knapp, Spencer; Choe, Yun H.; Reilly, Eileen

doi:10.1016/0040-4039(93)88054-m

Cited by 23 publications

(9 citation statements)

References 21 publications

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“…Two approaches to the methyl b-cellobioside analogue 5 were investigated ( Scheme 1), viz. alkylation of the hydroximolactam 19 [2] with the triflate 12 [16], and condensation of the thiogluconolactam 20 [26] with the hydroxylamine 14.…”

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confidence: 99%

“…Attempts to prepare the a-d-configured disaccharide analogue 23 by O-alkylation of the hydroximolactam 19 with the triflate 16 [16] [35] failed under conditions that proved successful for the preparation of the anomeric analogue 21. Decomposition of the triflate 16 proceeded more rapidly than its substitution by the hydroximolactam 19, while milder methods, such as treatment with NaH, [18]crown-6 ether in THF or in THF/DMPU at 238 [28], or with Hünigs base and DMPU did not promote substitution.…”

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confidence: 99%

“…Higher temperatures led to degradation of the triflate, while the lactam oxime was recovered. However, at 228, the triflate 16 was smoothly converted to the Scheme 1 a) Tf 2 O, pyridine, CH 2 Cl 2 ; 93% (12), 90% (16). b) N-Hydroxyphthalimide (FtNOH), DMPU, Et(i-Pr) 2 N or Et 3 N; 91% (13), 76% (17).…”

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confidence: 99%

“…Obviously, the selectivity is readily influenced by additional substituents at the hydroximo function. [16]. At À 158, Tf 2 O (8.6 g, 5.0 ml, 32.7 mmol) was added dropwise within 20 min to a stirred suspension of 11 [27] (7.6 g, 16.0 mmol), pyridine (2.6 ml, 32.7 mmol), and 3-molecular sieves (0.2 g) in CH 2 Cl 2 (50 ml).…”

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confidence: 99%

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Inhibition of Glycosidases by Lactam Oximes: Influence of the Aglycon in Disaccharide Analogues

Vonhoff

Heightman

Vasella

1998

HCA

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The influence of a substituent at the hydroximo function of the lactam analogue 1 on the inhibition of β‐ and α‐glucosidases is evaluated. In contrast to 1, the O‐alkyl oximes 5, 6, 9, and 10 are selective inhibitors of β‐glucosidases. Alkylation of the D‐gluconohydroximo‐1,5‐lactam 19 with the triflate 12, or condensation of the thiogluconolactam 20 with the hydroxylamines 14 or 18 afforded the benzylated cellobioside analogues 21 and 23, respectively. The O‐alkyl oximes 33 and 39 were prepared similarly (Scheme 3). Deprotection afforded the cellobioside analogues 5 and 6, and the O‐alkyl oximes 9 and 10. The lactam O‐alkyl oximes 5, 6, 9, and 10 are strong inhibitors of the β‐glucosidase from C. saccharolyticum (IC50=0.3 – 8 μM) and, with exception of the dodecyl analogue 9 (IC50=2 μM), moderate‐to‐weak inhibitors of β‐glucosidases from sweet almond (IC50=60 – 1000 μM; see Table). In contrast to the strong inhibition of α‐glucosidase from brewer's yeast by 1 (Ki=2.9 μM), the ethers 5, 6, and 10 are weak inhibitors of this enzyme (IC50 between 2500 and >5000 μM). Similarly, the D‐galactohydroximo‐1,5‐lactam 7 is a potent inhibitor of the α‐galactosidase from coffee beans and of the β‐galactosidases from bovine liver and E. coli (Ki=5, 10, and 0.1 μM, resp.), while the lactoside analogue 8 is a strong inhibitor of the E. coli β‐galactosidase (Ki=0.1 μM), but a moderate‐to‐weak inhibitor of coffee‐bean α‐galactosidase and bovine‐liver β‐galactosidase (Ki=250 μM and IC50=2500 μM, resp.). The galacto‐configured lactam oximes 7 and 8 are good inhibitors of the β‐glucosidase isolated from C. saccharolyticum (Ki=2.5 and 3.3 μM, resp.).

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confidence: 99%

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confidence: 99%

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confidence: 99%

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confidence: 99%

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Inhibition of Glycosidases by Lactam Oximes: Influence of the Aglycon in Disaccharide Analogues

Vonhoff

Heightman

Vasella

1998

HCA

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“…11 Sugar amidines have been investigated as inhibitors of carbohydrate-processing enzymes. [12][13][14][15][16][17][18][19][20][21][22][23] Amidines are strong bases and are usually protonated under physiological conditions.…”

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confidence: 99%

Hydrogen Bonding Networks and Solid-State Conversions in Benzamidinium Salts

Kamali

Aljohani

McArdle

et al. 2015

Crystal Growth & Design

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Ten benzamidinium salts of carboxylic acids, amides and sulfonamides have been crystallized from solution. Single-crystal X-ray analyses revealed various hydrogen bonding motifs which are discussed in terms of supramolecular synthons and graph sets. Benzamidinium hydrogen maleate (5a) crystallizes as large needles of up to > 3 cm length. Attempts to influence the crystal habit and size through a change of solvent and the presence of additives yielded a second polymorph (5b). The formation of the benzamidinium salts by mechanochemical reaction was also investigated. Grinding of benzamidine with nicotinic acid, salicylic acid, paminobenzoic acid, cyanuric acid, pimelic acid, saccharin and sulfathiazole with mortar and pestle or using a ball-mill gave compounds identical to those obtained by crystallization from solution. Time-dependent X-ray powder patterns of a stoichiometric benzamidine/cyanuric acid mixture suggested that the mechanochemical salt formation occured via the amorphous state. Ball-milling of benzamidine with sulfamerazine generated amorphous benzamidinium sulfamerazinate that was stable towards crystallization for at least two weeks, when stored at 25 % relative humidity.2

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Neue Erkenntnisse über Hemmung, Struktur und Mechanismus konfigurationserhaltender Glycosidasen

Heightman

Vasella

1999

Angewandte Chemie

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Nicht „von oben”︁, sondern „von der Seite”︁ protonieren konfigurationserhaltende β‐Glycosidasen ihr Substrat (siehe schematische Darstellung) als erster Schritt bei der Spaltung der glycosidischen Bindung, wobei die katalytische Säure entweder anti‐ oder syn‐ständig zur endocyclischen C1‐O‐Bindung ist. Einzelheiten der Wirkungsweise von Glycosidasen wurden durch Kombination der Synthese von Glycosidasehemmern mit deren enzymkinetischer Untersuchung und der Analyse der Kristallstrukturen von Glycosidasen und Glycosidase‐Inhibitor‐Komplexen aufgeklärt.

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Amidine pseudodisaccharides

Cited by 23 publications

References 21 publications

Inhibition of Glycosidases by Lactam Oximes: Influence of the Aglycon in Disaccharide Analogues

Inhibition of Glycosidases by Lactam Oximes: Influence of the Aglycon in Disaccharide Analogues

Hydrogen Bonding Networks and Solid-State Conversions in Benzamidinium Salts

Neue Erkenntnisse über Hemmung, Struktur und Mechanismus konfigurationserhaltender Glycosidasen

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