Water soluble biguanide salts and their 1,3,5-triazine derivatives as inhibitors of acetylcholinesterase and α-glucosidase

AbstractSeven biguanide derivatives were prepared by the nucleophilic reaction between dicyandiamide and p-substitute aniline derivatives or memantine or adamantine under acidic conditions. The cyclization of the biguanide compounds were also conducted via acetone to give 1,3,5-triazine derivatives. The structures of the synthesized compounds were characterized by analytical methods. The solid state structures of [HL5]Cl, [H2L7]Cl2, [HL1a]Cl and [HL5a]Cl were investigated by X-ray diffraction study. The acetylcholinesterase and α-glucosidase inhibitor properties of the compounds were then evaluated by the spectroscopic method. The compounds were found to show considerable acetylcholinesterase and α-glucosidase inhibitory activities compared to the approved drugs. The cyclization of biguanide derivatives with acetone did not affect inhibition of acetylcholinesterase, yet increased the α-glucosidase inhibition.

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Liquid crystalline polyureas with oligo(ethylene glycol) sequences

e-Polymers ◽

10.1515/epoly.2010.10.1.1425 ◽

2010 ◽

Vol 10 (1) ◽

Author(s):

Shahram Mehdipour-Ataei ◽

Leila Akbarian-Feizi

Keyword(s):

Liquid Crystalline ◽

Spectroscopic Method ◽

Polymerization Reaction ◽

X Ray Diffraction ◽

Subsequent Reaction ◽

Scanning Calorimetry ◽

Polar Solvents ◽

X Ray ◽

H Nmr ◽

Ft Ir

AbstractA diamine monomer containing ester, amide and ether functional groups was prepared and its polymerization reaction with different diisocyanates to give main chain poly(ester amide ether urea)s was investigated. The monomer was synthesized via reaction of terephthaloyl chloride with 4-hydroxybenzoic acid and subsequent reaction of the resulted diacid with 1,8-diamino-3,6-dioxaoctane. The polymers were characterized by FT-IR and 1H-NMR spectroscopic method and elemental analysis. The resulting polymers exhibited excellent solubility in polar solvents. Crystallinity of the resulted polymers was evaluated by wide-angle X-ray diffraction (WXRD) method, and they exhibited semi-crystalline patterns. The glass transition temperatures (Tg) of the polymers determined by differential scanning calorimetry (DSC) and dynamic mechanical thermal analysis (DMTA) were in the range of 88-112 °C. The temperatures for 10% weight loss (T10) from their thermogravimetric analysis (TGA) curves were found to be in the range of 297-312 °C in air. Also the prepared polyureas showed liquid crystalline character.

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Synthesis and structure of large 24-mer and 36-mer oxamate-based macrocycles

Zeitschrift für Naturforschung B ◽

10.1515/znb-2017-0020 ◽

2017 ◽

Vol 72 (7) ◽

pp. 461-474 ◽

Cited By ~ 3

Author(s):

Saddam Weheabby ◽

Mohammad A. Abdulmalic ◽

Evgeny A. Kataev ◽

Tatiana A. Shumilova ◽

Tobias Rüffer

Keyword(s):

Oxalyl Chloride ◽

Spectroscopic Studies ◽

Equimolar Amount ◽

X Ray Diffraction ◽

Intermolecular Hydrogen Bonds ◽

X Ray ◽

Accessible Volume ◽

Hydrogen Bond Interactions ◽

Work Up ◽

Solid State Structures

AbstractPoly(cyclic) oxamates represent novel and potentially multidentate ligands for coordination chemistry. To obtain them, the treatment of 2-nitroaniline with two equivalents of oxalyl chloride afforded N,N′-bis(2-nitrophenyl)oxalamide (1), and by reduction of 1 with [NH4][CO2H] and Pd/C, N,N′-bis(2-aminophenyl)oxalamide (2, bapoxH6) was synthesized. After the addition of an equimolar amount of oxalyl chloride to a THF solution of 2 and aqueous work-up the 24-membered macrocycle H8L2 was obtained. In analogues experiments, the addition of ethoxalyl and oxalyl chloride to 2 afforded the 36-membered macrocycle H12L3. The addition of Cu(OAc)2·H2O and NaOH to 2 gave rise to the formation of [Cu2(bapoxH4)(OAc)2] (4). The identities of 1, 2 and H8L2 were determined by elemental analysis, IR, NMR spectroscopic studies and by mass spectrometry. The solid state structures of H8L2, H12L3 and 4 have been determined by single-crystal X-ray diffraction studies. Macrocycle H12L3 forms chains through intermolecular hydrogen bonds, while packing of 4 consists of layers held by intermolecular dispersion and hydrogen bond interactions. 24-mer H8L2 forms a cavity with a diameter of about 7.5 Å corresponding to an accessible volume of about 120 Å3 according to the well-established 55% solution and was found to bind bromide and iodide anions selectively.

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Syntheses, Solid-state Structures and Catalytic Activity of Zinc Carboxylate Complexes in Lactide Polymerization

Zeitschrift für Naturforschung B ◽

10.5560/znb.2014-4133 ◽

2014 ◽

Vol 69 (11-12) ◽

pp. 1365-1374 ◽

Cited By ~ 6

Author(s):

Christoph Scheiper ◽

Christoph Wölper ◽

Dieter Bläser ◽

Joachim Roll ◽

Stephan Schulz

Keyword(s):

Ring Opening ◽

Zinc Complex ◽

X Ray Diffraction ◽

Polymerization Catalysts ◽

Co Catalyst ◽

Carboxylate Complexes ◽

X Ray ◽

Carboxylate Groups ◽

Solid State Structures ◽

Lactide Polymerization

Abstract Three dinuclear zinc carboxylate complexes [L1-3Zn(μ,η2-O2CPh)]2 (1, 2, 4) containing either the bidentate N,N′-chelating β-diketiminate ligand RNC(Me)C(H)C(Me)NR (R = 2,6-iPr2-C6H3, L1, complex 1), the tridentate O,N,N-chelating ligand OC(Me)C(H)C(Me)NCH2CH2NMe2 (L2, complex 2) or the bis-N,N′-chelating bis-β-diketiminate ligand RNC(Me)C(H)C(Me)NNC(Me)- C(H)C(Me)NR (R = 2,6-iPr2-C6H3, L3, complex 4) were synthesized and characterized including single-crystal X-ray diffraction. Reaction of the neutral bis-β-diketimine (L3(H)2) with two equivalents of ZnMe2 leads to the expected heteroleptic dinuclear zinc complex L3(ZnMe)2 3 in 93% yield. Further reaction with benzoic acid PhCO2H leads to complex 4. Complex 2 forms a rather strong carboxylate-bridged dimer, whereas the carboxylate groups in complexes 1 and 4 act as asymmetrical bridges between both Zn atoms, pointing to the formation of a weakly bonded dimer. The zinc atoms in 1 and 4 are tetrahedrally coordinated, whereas in 2 the coordination number is increased to five due to the coordination of the pendant donor arm. The ring opening polymerization (ROP) of rac-lactide was investigated with the zinc complexes 1-4 and diazabicycloundec-7-ene (DBU) as a co-catalyst. Complexes 2 and 3 are active polymerization catalysts, which in the presence of DBU converted 200 equiv. of rac-lactide into polylactide within 10 min at ambient temperature. The analysis of the crude polymer showed that the lactide polymerization with catalyst 2 occurs via a slightly modified activated-monomer mechanism.

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Engineering cocrystals of Paliperidone with enhanced solubility and dissolution characteristics

Arhiv za farmaciju ◽

10.5937/arhfarm71-32997 ◽

2021 ◽

Vol 71 (5) ◽

pp. 393-409

Author(s):

Earle Radha-Rani ◽

Gadela Venkata-Radha

Keyword(s):

Benzoic Acid ◽

Aqueous Solubility ◽

Water Soluble ◽

X Ray Diffraction ◽

X Ray ◽

Water Soluble Drug ◽

Novel Approach ◽

Enhanced Solubility ◽

Poorly Water Soluble ◽

Poorly Water Soluble Drug

In the present study, co-crystals (CCs) of Paliperidone (PPD) with coformers like benzoic acid (BA) and P-amino benzoic acid (PABA) were synthesized and characterized to improve the physicochemical properties and dissolution rate. CCs were prepared by the solvent evaporation (SE) technique and were compared with the products formed by neat grinding (NG) and liquid assisted grinding (LAG) in their enhancement of solubility. The formation of CCs was confirmed by the IR spectroscopy, powder X-ray diffraction and thermal analysis methods. The saturation solubility studies indicate that the aqueous solubility of PPD-BA and PPD-PABA CCs was significantly improved to 1.343±0.162mg/ml and 1.964±0.452mg/ml, respectively, in comparison with the PPD solubility of 0.473mg/ml. This increase in solubility is 2.83-and 3.09-fold, respectively. PPD exhibited a poor dissolution of 37.8% in 60min, while the dissolution of the CCs improved tremendously to 96.07% and 89.65% in 60min. CCs of PPD with BA and PABA present a novel approach to overcome the solubility challenges of poorly water-soluble drug PPD.

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Two copper(II) coordination polymers constructed by bis(4-(1H-imidazol-1-yl)phenyl)methanone and dicarboxylate ligands

Zeitschrift für Naturforschung B ◽

10.1515/znb-2016-0225 ◽

2017 ◽

Vol 72 (4) ◽

pp. 257-261 ◽

Cited By ~ 12

Author(s):

Gao-Feng Wang ◽

Xiao Zhang ◽

Shu-Wen Sun ◽

Hong Sun ◽

Hui Li ◽

...

Keyword(s):

Infrared Spectroscopy ◽

Single Crystal ◽

Weak Interactions ◽

X Ray Diffraction ◽

X Ray ◽

Elemental Analyses ◽

Solvothermal Methods ◽

Solid State Structures ◽

Aromatic Carboxylate ◽

Neutral Metal

AbstractTwo new copper(II) complexes, {[Cu(bipmo)(npa)]}n (1) and {[Cu(bipmo)(pa)]}n (2) (bipmo=bis(4-(1H-imidazol-1-yl)phenyl)methanone), were synthesized by solvothermal methods and structurally characterized by elemental analyses, infrared spectroscopy, and single-crystal X-ray diffraction. The results from single-crystal X-ray diffraction data indicate that the solid state structures of 1 and 2 consist of neutral metal aromatic carboxylate layers, which are pillared by the weak interactions to generate 3D architectures. The topological structures of 1 and 2 are uninodal nets based on 4-connected nodes with the Schläfli symbol of (65·8).

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Bis(dicarbollide) Complexes of Transition Metals as a Platform for Molecular Switches. Study of Complexation of 8,8′-Bis(methylsulfanyl) Derivatives of Cobalt and Iron Bis(dicarbollides)

Molecules ◽

10.3390/molecules25235745 ◽

2020 ◽

Vol 25 (23) ◽

pp. 5745

Author(s):

Sergey A. Anufriev ◽

Sergey V. Timofeev ◽

Alexei A. Anisimov ◽

Kyrill Yu. Suponitsky ◽

Igor B. Sivaev

Keyword(s):

Solid State ◽

Transition Metal ◽

Molecular Switches ◽

X Ray Diffraction ◽

Chelate Complexes ◽

X Ray ◽

Complexes Of Transition Metals ◽

Silver Palladium ◽

Solid State Structures ◽

Derivatives Of

Complexation of the 8,8′-bis(methylsulfanyl) derivatives of cobalt and iron bis(dicarbollides) [8,8′-(MeS)2-3,3′-M(1,2-C2B9H10)2]− (M = Co, Fe) with copper, silver, palladium and rhodium leads to the formation of the corresponding chelate complexes, which is accompanied by a transition from the transoid to the cisoid conformation of the bis(dicarbollide) complex. This transition is reversible and can be used in design of coordination-driven molecular switches based on transition metal bis(dicarbollide) complexes. The solid-state structures of {(Ph3P)ClPd[8,8′- (MeS)2-3,3′-Co(1,2-C2B9H10)2-κ2-S,S′]} and {(COD)Rh[8,8′-(MeS)2-3,3′-Co(1,2-C2B9H10)2-κ2-S,S′]} were determined by single crystal X-ray diffraction.

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Facile synthesis of water-soluble graphene-based composite: Non-covalently functionalized with chitosan-ionic liquid conjugation

Functional Materials Letters ◽

10.1142/s1793604716500454 ◽

2016 ◽

Vol 09 (03) ◽

pp. 1650045 ◽

Cited By ~ 7

Author(s):

Pei-Ying Li ◽

Kai-Yu Cheng ◽

Xiu-Cheng Zheng ◽

Pu Liu ◽

Xiu-Juan Xu

Keyword(s):

Electron Microscopy ◽

Ionic Liquid ◽

Chemical Reduction ◽

Water Soluble ◽

X Ray Diffraction ◽

Facile Synthesis ◽

X Ray ◽

Transmission Electron ◽

Vis Spectroscopy ◽

Text Interaction

Chitosan-ionic liquid conjugation (CILC), which was prepared through the reaction of 1-(4-bromobutyl)-3-methylimidazolium bromide (BBMIB) with chitosan, was firstly used to prepare functionalized graphene composite via the chemical reduction of graphene oxide (GO). The obtained water soluble graphene-based composite was characterized by transmission electron microscopy (TEM), scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), ultraviolet-visible (UV–Vis) spectroscopy and so on. CILC-RGO showed excellent dispersion stability in water at the concentration of 2.0 mg/mL, which was stable for several months without any precipitate. This may be ascribed to the electrostatic attraction and [Formula: see text]–[Formula: see text] interaction between CILC and graphene.

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Structural Characterization of a Plutonium Sequestering Agent Complex by Synchrotron X-Ray Diffraction

MRS Proceedings ◽

10.1557/proc-986-0986-oo08-01 ◽

2006 ◽

Vol 986 ◽

Author(s):

Anne E. V. Gorden ◽

G. Szigethy ◽

D. K. Shuh ◽

B. E. F. Tiedemann ◽

J. Xu ◽

...

Keyword(s):

National Laboratory ◽

Selective Extraction ◽

Biological Transport ◽

X Ray Diffraction ◽

X Ray ◽

Selective Ligand ◽

Detailed Evaluation ◽

Biomimetic Approach ◽

Solid State Structures

AbstractNew ligands and materials are required that can coordinate, sense, and purify actinides for selective extraction and reduction of toxic, radioactive wastes from the mining and purification of actinides. The similarities in the chemical, biological transport, and distribution properties of Fe(III) and Pu(IV) inspired a biomimetic approach to the development of sequestering agents for actinides. A detailed evaluation of the structure and bonding of actinide coordinating ligands like these is important for the design of new selective ligand systems. Knowing the difficulty with working with the crystals resulting from these ligand systems and safe handling considerations for working with Pu, procedures were developed that utilize the Advanced Light Source of Lawrence Berkeley National Laboratory to determine the solid-state structures of Pu complexes by X-ray diffraction.

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Complexes of trimethylsilyl trifluoromethanesulfonate with nitrogen, oxygen, and phosphorus donors

Canadian Journal of Chemistry ◽

10.1139/cjc-2015-0435 ◽

2016 ◽

Vol 94 (4) ◽

pp. 424-429 ◽

Cited By ~ 8

Author(s):

Alasdair P.M. Robertson ◽

Saurabh S. Chitnis ◽

Seth Chhina ◽

Hector J. Cortes S. ◽

Brian O. Patrick ◽

...

Keyword(s):

Solid Phase ◽

Donor Ligands ◽

Solution Stability ◽

Ambient Conditions ◽

X Ray Diffraction ◽

X Ray ◽

Lewis Bases ◽

Trimethylsilyl Trifluoromethanesulfonate ◽

Solid State Structures ◽

Lower Basicity

The Lewis acceptor chemistry of Me3SiOTf with p-block Lewis bases has been explored and a library of complexes has been characterized by spectroscopic and, where possible, crystallographic methods. Compounds with the generic formula [Me3Si(L)][OTf] (L = 4-dmap, pyr, imz, OPMe3, OPCy3, OPPh3, OpyrMe, dmso, PMe3) were isolated from 1:1 mixtures of Me3SiOTf and the respective ligand in CH2Cl2. Characterization by NMR spectroscopy confirmed the solution stability of all but [Me3Si(PMe3)][OTf], with indications that the latter dissociates into PMe3 and Me3SiOTf. Solid-state structures of [Me3Si(4-dmap)][OTf], [Me3Si(pyr)][OTf], [Me3Si(OPCy3)][OTf], [Me3Si(OPPh3)][OTf], [Me3Si(OpyrMe)][OTf], and [Me3Si(PMe3)][OTf] were elucidated by single crystal X-ray diffraction, confirming the envisaged ionic formulations resulting from the displacement of the OTf anion from the silicon center of Me3SiOTf by the incoming ligand. Mixtures of Me3SiOTf with other related donors, including ChPPh3 (Ch = S or Se), NEt3, SMe2, PPh3, 2,2′-bipy, or Me2CO, show no evidence of reaction under ambient conditions, reflecting the lower basicity and (or) greater steric encumbrance of these ligands. Reactions of Me3SiOTf with bis-donor ligands yielded complexes of the generic formulae [Me3Si(L–L)SiMe3][OTf]2 (L–L = 4,4′-bipy, tmeda, dmpe) and [Me3Si(L–L)][OTf] (L–L = 4,4′-bipy, tmeda, dmpe). The tmeda and dmpe complexes, however, were found to dissociate in solution, with complexes only prevailing in the solid phase. X-ray diffraction studies of [Me3Si(4,4′-bipy)SiMe3][OTf]2 and [Me3Si(dmpe)SiMe3][OTf]2 confirmed the expected connectivities and ionic formulations, with Si–ligand bond lengths comparable to those observed in [Me3Si(pyr)][OTf] and [Me3Si(PMe3)][OTf], respectively.

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Tensile, physical, and microstructure properties of glycine treated cotton fibers

Textile Research Journal ◽

10.1177/0040517517700196 ◽

2017 ◽

Vol 88 (12) ◽

pp. 1356-1366 ◽

Cited By ~ 3

Author(s):

Rechana Remadevi ◽

Stuart Gordon ◽

Xungai Wang ◽

Rangam Rajkhowa

Keyword(s):

Linear Density ◽

Cotton Fibers ◽

Acidic Ph ◽

Alkaline Ph ◽

X Ray Diffraction ◽

Density Measurements ◽

X Ray ◽

Acidic Conditions ◽

Improved Strain ◽

Control Samples

In this paper, the effect of aqueous glycine treatments at different pH on the tensile properties of cotton fibers is reported. The effects on linear density and X-ray diffraction crystallinity were also evaluated. Glycine treated fibers at alkaline pH (i.e. at pH 11) produced fibers with higher linear density than control (untreated) and glycine treatments at acidic pH. The same treatment also increased strain values in cotton fibers by as much as 36%. Interestingly, similar changes in strain were observed under acidic conditions, especially at pH4, although the changes were smaller. Specific stress values normalized by the linear density measurements were not significantly different from control samples. The results of this research demonstrated improved strain properties of cotton fibers after aqueous glycine treatment at suitable conditions.

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