Inhibitors of endo-α-mannosidase. Part III. Congeners of 1-deoxy-3-O-(α-D-glucopyranosyl)-mannojirimycin modified in the glucose unit

1993 ◽  
Vol 71 (11) ◽  
pp. 1943-1954 ◽  
Author(s):  
Ulrike Spohr ◽  
Mimi Bach
Keyword(s):  
Complex Formation ◽  
Hydrogen Bonds ◽  
Binding Site ◽  
High Specificity ◽  
Enzyme Complex ◽  
Chemical Modifications ◽  
Intermolecular Hydrogen Bonds ◽  
Strong Inhibitor ◽  
Glucose Unit ◽  
Glycoprotein Processing

The syntheses of congeners of 1-deoxy-3-O-(α-D-glucopyranosyl)-mannojirimycin (1), a strong inhibitor of the glycoprotein-processing endo-mannosidase, are described. The chemical modifications of 1 involved all monodeoxy-genations and mono-O-methylations of the glucose unit and the replacement of this unit by D-galactose, D-xylose, and 2-chloro-2-deoxy-D-glucose. As reported previously, none of the modifications of 1, including deoxygenations and O- and N-methylations of the deoxymannojirimycin unit, improved the inhibitory properties, but demonstrated the high specificity in the recognition of 1 by the enzyme and allowed the assignment of intermolecular hydrogen bonds of the inhibitor • enzyme complex. Essential for complex formation were found NH-5, OH-2, OH-4, and OH-6 of the DMJ unit, as well as OH-3′, OH-4′, and CH2-6′ of the glucose unit. The residual activities on deoxygenating the OH-2′ and OH-6′ groups of 1 suggest their involvement at the periphery of the binding site.

Inhibitors of endo-α-mannosidase. Part II. 1-Deoxy-3-O-(α-D-glucopyranosyl)-mannojirimycin and congeners modified in the mannojirimycin unit

1993 ◽  
Vol 71 (11) ◽  
pp. 1928-1942 ◽  
Author(s):  
Ulrike Spohr ◽  
Mimi Bach ◽  
Robert G. Spiro
Keyword(s):  
Hydrogen Bonds ◽  
Conformational Analysis ◽  
Chemical Shifts ◽  
Hydroxyl Groups ◽  
Enzyme Complex ◽  
Chemical Modifications ◽  
Intermolecular Hydrogen Bonds ◽  
Glycoprotein Processing ◽  
Nuclear Overhauser ◽  
Reported Data

The syntheses of 1-deoxy-3-O-(α-D-glucopyranosyl)-mannojirimycin (9) and its 2-deoxy, 2-O-methyl, 4-deoxy, 4-O-methyl, 6-deoxy, 6-O-methyl, N-methyl, and N-propyl congeners are described. Since 9 was previously shown to effectively inhibit endo-α-D-mannosidase, a glycoprotein-processing hydrolase, these chemical modifications were designed to assist in the assessment of intermolecular hydrogen bonds of the inhibitor–enzyme complex. The previously reported data require that all hydroxyl groups of the deoxymannojirimycin unit of 9, namely, OH-2, OH-4, OH-6, and also the NH-5 group, interact with charged and polar groupings of the enzyme, since deoxygenations and alkylations abolished or significantly reduced activities. Conformational analysis of 9 and some of its congeners based on NMR chemical shifts, experimental and theoretical nuclear Overhauser enhancements, and HSEA calculations were performed. The chemical modifications of the glucose unit of 9 are described in the accompanying paper.

A Crystallographic Study of Bis[S-benzyl-5-bromo-2-oxoindolin-3-ylidenemethanehydrazonthioate] Disulfide Solvated with Dimethylsulfoxide

2012 ◽  
Vol 9 (2) ◽  
pp. 87
Author(s):  
Mohd Abdul Fatah Abdul Manan ◽  
M. Ibrahim M. Tahir ◽  
Karen A. Crouse ◽  
Fiona N.-F. How ◽  
David J. Watkin
Keyword(s):  
Crystal Structure ◽  
Hydrogen Bonds ◽  
Solvent Molecule ◽  
Site Occupancy ◽  
Unit Cell Parameters ◽  
Intermolecular Hydrogen Bonds ◽  
Triclinic Space Group ◽  
Cell Parameters ◽  
Crystallographic Study ◽  
Thiol Form

The crystal structure of the title compound has been determined. The compound crystallized in the triclinic space group P -1, Z = 2, V = 1839 .42( 18) A3 and unit cell parameters a= 11. 0460( 6) A, b = 13 .3180(7) A, c=13. 7321 (8) A, a = 80.659(3 )0, b = 69 .800(3 )0 and g = 77 .007 (2)0 with one disordered dimethylsulfoxide solvent molecule with the sulfur and oxygen atoms are distributed over two sites; S101/S102 [site occupancy factors: 0.6035/0.3965] and 0130/0131 [site occupancy factor 0.3965/0.6035]. The C22-S2 l and C 19-S20 bond distances of 1. 779(7) A and 1. 788(8) A indicate that both of the molecules are connected by the disulfide bond [S20-S21 2.055(2) A] in its thiol form. The crystal structure reveals that both of the 5-bromoisatin moieties are trans with respect to the [S21-S20 and CI 9-Nl 8] and [S20-S21 and C22-N23] bonds whereas the benzyl group from the dithiocarbazate are in the cis configuration with respect to [S21-S20 and C19-S44] and [S20-S21 and C22-S36] bonds. The crystal structure is further stabilized by intermolecular hydrogen bonds of N9-H35···O16 formed between the two molecules and N28-H281 ···O130, N28-H281 ···O131 and C4 l-H4 l l ···O 131 with the solvent molecule.

scholarly journals Organotin(IV) selenate derivatives – Crystal structure of [{(Ph3Sn)2SeO4} ⋅ CH3OH] n

2021 ◽  
Vol 44 (1) ◽  
pp. 213-217
Author(s):  
Waly Diallo ◽  
Hélène Cattey ◽  
Laurent Plasseraud
Keyword(s):  
Crystal Structure ◽  
Solid State ◽  
Hydrogen Bonds ◽  
Point Of View ◽  
Intermolecular Hydrogen Bonds

Abstract Crystallization of [(Ph3Sn)2SeO4] ⋅ 1.5H2O in methanol leads to the formation of [{(Ph3Sn)2SeO4} ⋅ CH3OH] n (1) which constitutes a new specimen of organotin(IV) selenate derivatives. In the solid state, complex 1 is arranged in polymeric zig-zag chains, composed of alternating Ph3Sn and SeO4 groups. In addition, pendant Ph3Sn ⋅ CH3OH moieties are branched along chains according to a syndiotactic organization and via Sn-O-Se connections. From a supramolecular point of view, intermolecular hydrogen bonds established between the selenate groups (uncoordinated oxygen) and the hydroxyl functions (CH3OH) of the pendant groups link the chains together.

scholarly journals Two enantiomeric perovskite ferroelectrics with a high Tc raised by inserting intermolecular hydrogen bonds

APL Materials ◽  
2021 ◽  
Vol 9 (3) ◽  
pp. 031102
Author(s):  
Hui Ye ◽  
Wang-Hua Hu ◽  
Wei-Jian Xu ◽  
Ying Zeng ◽  
Xiao-Xian Chen ◽  
...  
Keyword(s):  
Hydrogen Bonds ◽  
Intermolecular Hydrogen Bonds ◽  
High Tc

scholarly journals Cooperation/Competition between Halogen Bonds and Hydrogen Bonds in Complexes of 2,6-Diaminopyridines and X-CY3 (X = Cl, Br; Y = H, F)

Symmetry ◽  
2021 ◽  
Vol 13 (5) ◽  
pp. 766
Author(s):  
Barbara Bankiewicz ◽  
Marcin Palusiak
Keyword(s):  
Complex Formation ◽  
Hydrogen Bonds ◽  
Dft Calculations ◽  
Electrostatic Interactions ◽  
Dipole Moments ◽  
Main Role ◽  
Halogen Bonds ◽  
Topological Parameters ◽  
Leading Role ◽  
The Impact

The DFT calculations have been performed on a series of two-element complexes formed by substituted 2,6-diaminopyridine (R−PDA) and pyridine (R−Pyr) with X−CY3 molecules (where X = Cl, Br and Y = H, F). The primary aim of this study was to examine the intermolecular hydrogen and halogen bonds in the condition of their mutual coexistence. Symmetry/antisymmetry of the interrelation between three individual interactions is addressed. It appears that halogen bonds play the main role in the stabilization of the structures of the selected systems. However, the occurrence of one or two hydrogen bonds was associated with the favourable geometry of the complexes. Moreover, the impact of different substituent groups attached in the para position to the aromatic ring of the 2,6-diaminopyridine and pyridine on the character of the intermolecular hydrogen and halogen bonds was examined. The results indicate that the presence of electron-donating substituents strengthens the bonds. In turn, the presence of electron-withdrawing substituents reduces the strength of halogen bonds. Additionally, when hydrogen and halogen bonds lose their leading role in the complex formation, the nonspecific electrostatic interactions between dipole moments take their place. Analysis was based on geometric, energetic, and topological parameters of the studied systems.

scholarly journals Tetrahydroberberine, a pharmacologically active naturally occurring alkaloid

2015 ◽  
Vol 71 (4) ◽  
pp. 262-265 ◽  
Author(s):  
Subramanya Pingali ◽  
James P. Donahue ◽  
Florastina Payton-Stewart
Keyword(s):  
Hydrogen Bonds ◽  
Crystal Packing ◽  
Racemic Mixture ◽  
Inversion Center ◽  
Intermolecular Hydrogen Bonds ◽  
Naturally Occurring ◽  
Pharmacologically Active

Tetrahydroberberine (systematic name: 9,10-dimethoxy-5,8,13,13a-tetrahydro-6H-benzo[g][1,3]benzodioxolo[5,6-a]quinolizine), C20H21NO4, a widely distributed naturally occurring alkaloid, has been crystallized as a racemic mixture about an inversion center. A bent conformation of the molecule is observed, with an angle of 24.72 (5)° between the arene rings at the two ends of the reduced quinolizinium core. The intermolecular hydrogen bonds that play an apparent role in crystal packing are 1,3-benzodioxole –CH2...OCH3and –OCH3...OCH3interactions between neighboring molecules.

scholarly journals 2,6-Bis(4-methoxybenzylidene)cyclohexanone

2006 ◽  
Vol 62 (5) ◽  
pp. o1910-o1912 ◽  
Author(s):  
Ray J. Butcher ◽  
H. S. Yathirajan ◽  
B. K. Sarojini ◽  
B. Narayana ◽  
J. Indira
Keyword(s):  
Crystal Structure ◽  
Hydrogen Bonds ◽  
Title Compound ◽  
Photon Absorption ◽  
Intermolecular Hydrogen Bonds ◽  
Two Photon Absorption ◽  
Two Photon ◽  
Compound C ◽  
Centrosymmetric Dimers

The title compound, C22H22O3, demonstrates a two-photon absorption. Its metrical parameters are similar to those of related cyclohexanone derivatives. In the crystal structure, two sets of centrosymmetric dimers formed by weak C—H...O intermolecular hydrogen bonds combine to form molecular tapes along [101].

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