Conduction and dielectric polarisation in proteins and molecular complexes

The content of this investigation was to study the influence of β-cyclodextrin and hydroxy propyl-β-cyclodextrin complexation on enhancement of solubility and dissolution rate of isradipine. Based on preliminary phase solubility studies, solid complexes prepared by freeze drying method in 1:1 molar ratio were selected and characterized by DSC for confirmation of complex formation. Prepared solid dispersions were evaluated for drug content, solubility and in vitro dissolution. The physical stability of optimized formulation was studied at refrigerated and room temperature for 2 months. Solid state characterization of optimized complex performed by DSC and XRD studies. Dissolution rate of isradipine was increased compared with pure drug and more with HP-β-CD inclusion complex than β-CD. DSC and XRD analyzes that drug was in amorphous form, when the drug was incorporated as isradipine β-CD and HP-β-CD inclusion complex. Stability studies resulted in low or no variations in the percentage of complexation efficiency suggesting good stability of molecular complexes. The results conclusively demonstrated that the enhancement of solubility and dissolution rate of isradipine by drug-cyclodextrin complexation was achieved.

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Molecular Complexes of Monoammonium Glycyrrhizinate with Alphahederin and Hederasaponin C

Letters in Organic Chemistry ◽

10.2174/1570178612666141230234729 ◽

2015 ◽

Vol 12 (2) ◽

pp. 109-114 ◽

Cited By ~ 2

Author(s):

Leonid A. Yakovishin ◽

Vladimir I. Grishkovets ◽

Elena N. Korzh

Keyword(s):

Molecular Complexes ◽

Hederasaponin C

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Optical soliton molecular complexes in a passively mode-locked fibre laser

Nature Communications ◽

10.1038/s41467-019-08755-4 ◽

2019 ◽

Vol 10 (1) ◽

Cited By ~ 45

Author(s):

Z. Q. Wang ◽

K. Nithyanandan ◽

A. Coillet ◽

P. Tchofo-Dinda ◽

Ph. Grelu

Keyword(s):

Molecular Complexes ◽

Optical Soliton ◽

Fibre Laser

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PENTACOORDINATED MOLECULAR COMPLEXES OF ARYLTELLURIUM(IV) AND DIARYLTELLURIUM(IV) CHLORIDES WITH THIOSEMICARBAZONES

Phosphorous and Sulfur and the Related Elements ◽

10.1080/03086648808072889 ◽

1988 ◽

Vol 40 (1-2) ◽

pp. 27-32 ◽

Cited By ~ 2

Author(s):

Ajai K. Singht ◽

Jayanta K. Basumatary

Keyword(s):

Molecular Complexes

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The effect of terminal N-donor aromatic ligands on sensitization and emission of lanthanide ions in Zn2Ln (Ln = Eu, Tb) complexes with 4-biphenylcarboxylate anions

New Journal of Chemistry ◽

10.1039/d0nj05994c ◽

2021 ◽

Author(s):

Stanislav N. Melnikov ◽

Igor Evstifeev ◽

Stanislav A. Nikolaevskii ◽

Ivan V. Ananyev ◽

Evgenia Varaksina ◽

...

Keyword(s):

General Formula ◽

Molecular Complexes ◽

Lanthanide Ions ◽

Biphenylcarboxylic Acid

The systematical series of Zn-Ln trinuclear carboxylate molecular complexes with general formula [Zn2Ln(NO3)(phbz)6(L)2] (Ln = Eu, Gd, Tb; phbz is anion of 4-biphenylcarboxylic acid; L is pyridine, 2,3-lutidine or 2,2’-bipyridine)...

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Polymer Optical Waveguide Sensor Based on Fe-Amino-Triazole Complex Molecular Switches

Polymers ◽

10.3390/polym13020195 ◽

2021 ◽

Vol 13 (2) ◽

pp. 195

Author(s):

Muhammad Shaukat Khan ◽

Hunain Farooq ◽

Christopher Wittmund ◽

Stephen Klimke ◽

Roland Lachmayer ◽

...

Keyword(s):

Molecular Complex ◽

Electromagnetic Interference ◽

Optical Power ◽

Uv Curing ◽

Molecular Complexes ◽

Core Material ◽

Absorption Bands ◽

Electronic Temperature ◽

Polymer Waveguide ◽

Temperature Detection

We report on a polymer-waveguide-based temperature sensing system relying on switchable molecular complexes. The polymer waveguide cladding is fabricated using a maskless lithographic optical system and replicated onto polymer material (i.e., PMMA) using a hot embossing device. An iron-amino-triazole molecular complex material (i.e., [Fe(Htrz)2.85(NH2-trz)0.15](ClO4)2) is used to sense changes in ambient temperature. For this purpose, the core of the waveguide is filled with a mixture of core material (NOA68), and the molecular complex using doctor blading and UV curing is applied for solidification. The absorption spectrum of the molecular complex in the UV/VIS light range features two prominent absorption bands in the low-spin state. As temperature approaches room temperature, a spin-crossover transition occurs, and the molecular complex changes its color (i.e. spectral properties) from violet-pink to white. The measurement of the optical power transmitted through the waveguide as a function of temperature exhibits a memory effect with a hysteresis width of approx. 12 °C and sensitivity of 0.08 mW/°C. This enables optical rather than electronic temperature detection in environments where electromagnetic interference might influence the measurements.

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Structure activity relationships and the binding mode of quinolinone-pyrimidine hybrids as reversal agents of multidrug resistance mediated by P-gp

Scientific Reports ◽

10.1038/s41598-021-96226-6 ◽

2021 ◽

Vol 11 (1) ◽

Author(s):

Jerónimo Laiolo ◽

Priscila Ailin Lanza ◽

Oscar Parravicini ◽

Cecilia Barbieri ◽

Daniel Insuasty ◽

...

Keyword(s):

Multidrug Resistance ◽

Molecular Complexes ◽

Binding Mode ◽

Reversal Agents ◽

Structure Activity Relationships ◽

Structure Activity ◽

Doxorubicin Toxicity ◽

Key Residues ◽

Nanomolar Range ◽

Experimental Structure

AbstractP-gp-associated multidrug resistance is a major impediment to the success of chemotherapy. With the aim of finding non-toxic and effective P-gp inhibitors, we investigated a panel of quinolin-2-one-pyrimidine hybrids. Among the active compounds, two of them significantly increased intracellular doxorubicin and rhodamine 123 accumulation by inhibiting the efflux mediated by P-gp and restored doxorubicin toxicity at nanomolar range. Structure–activity relationships showed that the number of methoxy groups, an optimal length of the molecule in its extended conformation, and at least one flexible methylene group bridging the quinolinone to the moiety bearing the pyrimidine favored the inhibitory potency of P-gp. The best compounds showed a similar binding pattern and interactions to those of doxorubicin and tariquidar, as revealed by MD and hybrid QM/MM simulations performed with the recent experimental structure of P-gp co-crystallized with paclitaxel. Analysis of the molecular interactions stabilizing the different molecular complexes determined by MD and QTAIM showed that binding to key residues from TMH 4–7 and 12 is required for inhibition.

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