scholarly journals Preparation of Amylose-Oligo[(R)-3-hydroxybutyrate] Inclusion Complex by Vine-Twining Polymerization

Molecules ◽  
2021 ◽  
Vol 26 (9) ◽  
pp. 2595
Author(s):  
Jun-ichi Kadokawa ◽  
Yuki Wada ◽  
Kazuya Yamamoto
Keyword(s):  
Inclusion Complex ◽  
Inclusion Complexes ◽  
Water Soluble ◽  
Enzymatic Polymerization ◽  
X Ray Diffraction ◽  
Mechanism Of Formation ◽  
X Ray ◽  
Partial Formation ◽  
Glucan Phosphorylase ◽  
Polymerization Conditions

In this study, we attempted to prepare an amylose-oligo[(R)-3-hydroxybutyrate] (ORHB) inclusion complex using a vine-twining polymerization approach. Our previous studies indicated that glucan phosphorylase (GP)-catalyzed enzymatic polymerization in the presence of appropriate hydrophobic guest polymers produces the corresponding amylose–polymer inclusion complexes, a process named vine-twining polymerization. When vine-twining polymerization was conducted in the presence of ORHB under general enzymatic polymerization conditions (45 °C), the enzymatically produced amylose did not undergo complexation with ORHB. However, using a maltotriose primer in the same polymerization system at 70 °C for 48 h to obtain water-soluble amylose, called single amylose, followed by cooling the system over 7 h to 45 °C, successfully induced the formation of the inclusion complex. Furthermore, enzymatic polymerization initiated from a longer primer under the same conditions induced the partial formation of the inclusion complex. The structures of the different products were analyzed by X-ray diffraction, 1H-NMR, and IR measurements. The mechanism of formation of the inclusion complexes discussed in the study is proposed based on the additional experimental results.

Synthesis and Characterization of a Dumbbell-Shaped Polyrotaxane Based on Polytetrahydrofuran bis(3-aminopropyl) Terminated and α-Cyclodextrins Using Polyamidoamine (PAMAM) Dentrimers as Bulky Stoppers

2015 ◽  
Vol 1094 ◽  
pp. 41-48
Author(s):  
Ri Min Cong ◽  
Huai Qing Yu ◽  
Yan Gong Yang ◽  
Si Yi Yang ◽  
Jiao Li ◽  
...  
Keyword(s):  
Thermogravimetric Analysis ◽  
Inclusion Complex ◽  
Inclusion Complexes ◽  
Synthesis And Characterization ◽  
Wide Angle ◽  
X Ray Diffraction ◽  
X Ray ◽  
H Nmr ◽  
Channel Type

A dumbbell-shaped polyrotaxane based on polytetrahydrofuran bis (3-aminopropyl) terminated and α-cyclodextrins using polyamidoamine (PAMAM) dentrimers as bulky stoppers was successfully prepared. The1H NMR results show that the peaks of α-CDs in these polyrotaxanes are broadened compared with pure α-CDs. Wide-angle X-ray diffraction (XRD) measurements of the resulting polyrotaxanes suggest to produce a channel-type crystalline structure of inclusion complex. Thermogravimetric analysis (TGA) of the resultant polyrotaxanes show that α-CDs are significantly stabilized by the formation of the inclusion complexes.

Preparation and Characterization of Tea Polyphenols/Starch Inclusion Complex

2013 ◽  
Vol 432 ◽  
pp. 413-417 ◽  
Author(s):  
Li Ming Zhang ◽  
Zhi Ying Hu ◽  
Li Hu Yan ◽  
Run Liu Li ◽  
Cheng Wei Cao ◽  
...  
Keyword(s):  
Differential Scanning Calorimetry ◽  
Inclusion Complex ◽  
Inclusion Complexes ◽  
Tea Polyphenols ◽  
X Ray Diffraction ◽  
Scanning Calorimetry ◽  
X Ray ◽  
The Stability ◽  
Good Retention

In order to improving the stability and bioavailability of tea polyphenols (TP), the TP/starchinclusion complex(TPSIC) was prepared by adding TP to starch slurry during gelatinization, and its TPreleasing behaviorswas investigated. The formation of inclusion complex was confirmed by powder X-ray diffraction (XRD) and differential scanning calorimetry (DSC). The TPSIC showed a characteristic of V-type crystallinity and a looser gel matrix. The encapsulation increased the stability of TP and generated a good releasing behavior after enzymatic erosion. The lower releasing rate indicated that the prepared inclusion complexes had good retention ability and effectively reduced the releasing rate of TP. The releasing rate of TPSIC increased with the increase of TP concentration.

Crystal structure of an inclusion complex between chiral monoaza-15-crown-5 and S(–)-1-phenyl-ethyl ammonium percholorate

2003 ◽  
Vol 218 (5) ◽  
Author(s):  
Süheyla Özbey ◽  
F. B. Kaynak ◽  
M. Toğrul ◽  
N. Demirel ◽  
H. Hoşgören
Keyword(s):  
Crystal Structure ◽  
Inclusion Complex ◽  
Single Crystal ◽  
X Ray Diffraction ◽  
Space Group ◽  
X Ray ◽  
New Type

AbstractA new type of inclusion complex, S(–)-1 phenyl ethyl ammonium percholorate complex of R-(–)-2-ethyl - N - benzyl - 4, 7, 10, 13 - tetraoxa -1- azacyclopentadecane, has been prepared and studied by NMR, IR and single crystal X-ray diffraction techniques. The compound crystallizes in space group

Studies on the Preparation, Characterization and Solubility of -Cyclodextrin-Roxythromycin Inclusion Complexes

2009 ◽  
Vol 2 (2) ◽  
pp. 523-530
Author(s):  
D. Nagasamy Venkatesh ◽  
S. Karthick ◽  
M. Umesh ◽  
G. Vivek ◽  
R.M. Valliappan ◽  
...  
Keyword(s):  
Dissolution Rate ◽  
Inclusion Complexes ◽  
Phase Solubility ◽  
X Ray Diffraction ◽  
Scanning Calorimetry ◽  
X Ray ◽  
Ir Studies ◽  
Poorly Soluble ◽  
Poorly Soluble Drug

Roxythromycin/ β-cyclodextrin (Roxy/ β-CD) dispersions were prepared with a view to study the influence of β-CD on the solubility and dissolution rate of this poorly soluble drug. Phase-solubility profile indicated that the solubility of roxythromycin was significantly increased in the presence of β-cyclodextrin and was classified as AL-type, indicating the 1:1 stoichiometric inclusion complexes. Physical characterization of the prepared systems was carried out by differential scanning calorimetry (DSC), X-ray diffraction studies (XRD) and IR studies. Solid state characterization of the drug β-CD binary system using XRD, FTIR and DSC revealed distinct loss of drug crystallinity in the formulation, ostensibly accounting for enhancement of dissolution rate.

The Application of X-Ray Diffraction at Elevated Temperatures to Study the Mechanism of Formation of Sodium Tripolyphosphate

1961 ◽  
Vol 5 ◽  
pp. 276-284
Author(s):  
E. L. Moore ◽  
J. S. Metcalf
Keyword(s):  
High Temperature ◽  
Low Temperature ◽  
Amorphous Phase ◽  
Elevated Temperatures ◽  
Sodium Tripolyphosphate ◽  
X Ray Diffraction ◽  
Mechanism Of Formation ◽  
X Ray ◽  
Temperature Form ◽  
High Temperature Form

AbstractHigh-temperature X-ray diffraction techniques were employed to study the condensation reactions which occur when sodium orthophosphates are heated to 380°C. Crystalline Na4P2O7 and an amorphous phase were formed first from an equimolar mixture of Na2HPO4·NaH2PO4 and Na2HPO4 at temperatures above 150°C. Further heating resulted in the formation of Na5P3O10-I (high-temperature form) at the expense of the crystalline Na4P4O7 and amorphous phase. Crystalline Na5P3O10-II (low-temperature form) appears after Na5P3O10-I.Conditions which affect the yield of crystalline Na4P2O7 and amorphous phase as intermediates and their effect on the yield of Na5P3O10 are also presented.

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

2020 ◽  
Vol 235 (10) ◽  
pp. 465-475
Author(s):  
Ozge Gungor ◽  
Seda Nur Kertmen Kurtar ◽  
Muhammet Kose
Keyword(s):  
Spectroscopic Method ◽  
Substitute Aniline ◽  
Water Soluble ◽  
X Ray Diffraction ◽  
Nucleophilic Reaction ◽  
X Ray ◽  
Triazine Derivatives ◽  
Acidic Conditions ◽  
Approved Drugs ◽  
Solid State Structures

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.

scholarly journals Engineering cocrystals of Paliperidone with enhanced solubility and dissolution characteristics

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.

Characterization of the inclusion complex of the essential oil of Lantana camara L. and β-cyclodextrin by vibrational spectroscopy, GC–MS, and X-ray diffraction

2018 ◽  
Vol 91 (1-2) ◽  
pp. 95-104 ◽  
Author(s):  
Márcio dos S. Rocha ◽  
Sidney G. de Lima ◽  
Bartolomeu C. Viana ◽  
José Galberto Martins Costa ◽  
Francisco E. P. Santos
Keyword(s):  
Essential Oil ◽  
Inclusion Complex ◽  
Vibrational Spectroscopy ◽  
Lantana Camara ◽  
X Ray Diffraction ◽  
X Ray

THE COMPOSITION, STRUCTURE, AND MECHANISM OF FORMATION OF THE LINING OF THE GIZZARD OF THE CHICKEN

1964 ◽  
Vol 42 (1) ◽  
pp. 59-70 ◽  
Author(s):  
T. E. Webb ◽  
J. Ross Colvin
Keyword(s):  
Electron Microscope ◽  
Sedimentation Coefficient ◽  
Performic Acid ◽  
X Ray Diffraction ◽  
Mechanism Of Formation ◽  
Protein Layer ◽  
Covalent Bonds ◽  
X Ray ◽  
Disulphide Bonds ◽  
Composition Structure

The extracellular protein layer which surrounds the lumen of the gizzard of the chicken has been reinvestigated to determine if it is a keratin. The lining is insoluble in keratin solvents such as urea-bisulphite or Swan's reagent as well as thioglycollate and performic acid. In addition, it contains only 1.45% sulphur so that disulphide bonds cannot play a major role in its consolidation. The lining is insoluble in acids but readily dispersed in alkali without breaking of covalent bonds. The dispersion in alkali is retarded by electrolytes. The lining is hydrolyzed by trypsin and chymotrypsin at pH 8.0 but is resistant to pepsin at pH 2.0. An alkaline dispersion of the lining is heterogeneous in the ultracentrifuge, but not grossly so, with a mean sedimentation coefficient of 5.6 svedbergs. Electron microscope studies of the lining suggest it is an amorphous, precipitated protein, which is consistent with the observation of three hazy rings in X-ray diffraction powder patterns reflecting spacings of 3.5, 4.6, and 9.4 Å. Amino acid analysis shows a ratio of more than three acidic groups to one basic, with no carbohydrate residues and little lipid in the protein layer. These observations are interpreted as indicating the precipitation of an amorphous, non-keratin, acidic, abrasion-resistant protein from the glandular mucosa by the acid in the gizzard.

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