Study on the Inclusion Behavior of Cucurbit [n] uril with Phenylalanine

2011 ◽  
Vol 197-198 ◽  
pp. 1153-1156
Author(s):  
Ning Chen ◽  
Ya Bin Li
Keyword(s):  
1H Nmr ◽  
Interaction Mechanism ◽  
Acetate Buffer Solution ◽  
Molar Ratio ◽  
High Concentration ◽  
Buffer Solution ◽  
Visible Absorption ◽  
Nmr Spectrum ◽  
Application Range ◽  
Uv Visible

The characteristics of host-guest complexes between cucurbit[n]uril (CB [n]) and phenylalanine were investigated by UV-visible absorption spectroscopy in acetate buffer solution at room temperature. It was found that the UV-visible absorption increased steadily with constantly dropping the high concentration of cucurbit[6]uril (CB [6]) and cucurbit[8]uril (CB [8]) in the phenylalanine solution which indicates that there are some interaction betweenCB [n] and phenylalanine.Then CB [6] and phenylalanine at molar ratio of 1:1 to weigh while CB [8] and phenylalanine at molar ratio of 1:2, respectively, are both demonstrated by 1H NMR spectra. 1H NMR spectrum of complexes was obtained, indicating an enthalpic driving force for host-guest complexes. The possible interaction mechanism and inclusion mode were also discussed. This work may extend the application range of CB [n] in supramolecular and pharmaceutical analysis.

The use of photogenerated iodine in determination of the dibazol content in solid and liquid dosage formulations

2021 ◽  
Vol 87 (2) ◽  
pp. 19-24
Author(s):  
E. V. Turusova
Keyword(s):  
Generation Time ◽  
Quantitative Estimation ◽  
Potato Starch ◽  
Analytical Signal ◽  
Acetate Buffer Solution ◽  
Molar Ratio ◽  
Buffer Solution ◽  
Solution Ph ◽  
Solid Dosage

A rapid method for the determination of Dibazol (bendazol hydrochloride) in liquid and solid dosage forms (DF) has been developed. The method is based on converting the drug into an analytical form and titrating the physiologically active compound (PAC) with a solution of photogenerated iodine obtained by irradiation of an auxiliary solution containing potassium iodide, a mixture of sensitizers (sodium eosinate: fluorescein: auramine, taken in a molar ratio of 1:1:1) and an acetate buffer solution (pH 5.6). A decrease in the titrant content in the cell due to interaction with Dibazol was recorded by a decrease in the current in the amperometric circuit. Stabilization of the current in the circuit indicated the completeness of the reaction, thus providing for estimation of the PAC content in a DF. Further irradiation of the solution and measurement of the generation time required to replenish the titrant loss in the cell also ensure the quantitative estimation of the PAC content in the preparation. The method has been tested on solid dosage form and sterile solutions of Dibazol intended for intramuscular and intravenous administration. A slight effect of stabilizers (hydrochloric acid, ethanol) and auxiliary substances (potato starch) present in the DF on the photogeneration of the titrant was observed. The determined Dibazol content in solid and liquid DF falls within the range recommended by the order of the Ministry of Health of the Russian Federation (26.10.2015 No. 751n) and OFS.1.4.2.0009.15, which indicates that the quality of the drug meets the GMP standards. The linear dependence of the analytical signal on the Dibazol concentration is observed in the range of 13.5 – 134.7 mg for the drug «Dibazol-UBF, tablets, 20 mg». The calculated limits of Dibazol detection and quantitative determination by changes in the current strength and generation time are (4.71; 3.56) and (14.26; 10.77) mg, respectively. The use of developed technique in the analysis of drugs containing Dibazol reduces both the time of single determination due to the absence of the need for standardization of solutions, and the cost of a single analysis, since it does not require the use of expensive equipment and reagents.

scholarly journals Preparation of Fe-DopedTiO2Nanotubes and Their Photocatalytic Activities under Visible Light

2013 ◽  
Vol 2013 ◽  
pp. 1-7 ◽  
Author(s):  
Honghui Teng ◽  
Shukun Xu ◽  
Dandan Sun ◽  
Ying Zhang
Keyword(s):  
Visible Light ◽  
Visible Region ◽  
Molar Ratio ◽  
X Ray Diffraction ◽  
Visible Absorption ◽  
X Ray ◽  
Transmission Electron ◽  
Photocatalytic Activities ◽  
Ultrasonic Assisted ◽  
Uv Visible

Fe-doped TiO2nanotubes (Fe-TNTs) have been prepared by ultrasonic-assisted hydrothermal method. The structure and composition of the as-prepared TiO2nanotubes were characterized by transmission electron microscopy, X-ray diffraction, and UV-Visible absorption spectroscopy. Their photocatalytic activities were evaluated by the degradation of MO under visible light. The UV-visible absorption spectra of the Fe-TNT showed a red shift and an enhancement of the absorption in the visible region compared to the pure TNT. The Fe-TNTs were provided with good photocatalytic activities and photostability and under visible light irradiation, and the optimum molar ratio of Ti : Fe was found to be 100 : 1 in our experiments.

scholarly journals Dynamic Hydrogen Production from Methanol/Water Photo-Splitting Using Core@Shell-Structured CuS@TiO2Catalyst Wrapped by High Concentrated TiO2Particles

2013 ◽  
Vol 2013 ◽  
pp. 1-10 ◽  
Author(s):  
Younghwan Im ◽  
Sora Kang ◽  
Kang Min Kim ◽  
Taeil Ju ◽  
Gi Bo Han ◽  
...  
Keyword(s):  
Hydrogen Production ◽  
Reduction Potential ◽  
Hydrogen Gas ◽  
Electronic Transitions ◽  
Core Shell ◽  
High Concentration ◽  
Visible Absorption ◽  
Long Wavelength ◽  
The Core ◽  
Uv Visible

This study focused on the dynamic hydrogen production ability of a core@shell-structured CuS@TiO2photocatalyst coated with a high concentration of TiO2particles. The rectangular-shaped CuS particles, 100 nm in length and 60 nm in width, were surrounded by a high concentration of anatase TiO2particles (>4~5 mol). The synthesized core@shell-structured CuS@TiO2particles absorbed a long wavelength (a short band gap) above 700 nm compared to that pure TiO2, which at approximately 300 nm, leading to easier electronic transitions, even at low energy. Hydrogen evolution from methanol/water photo-splitting over the core@shell-structured CuS@TiO2photocatalyst increased approximately 10-fold compared to that over pure CuS. In particular, 1.9 mmol of hydrogen gas was produced after 10 hours when 0.5 g of 1CuS@4TiO2was used at pH = 7. This level of production was increased to more than 4-fold at higher pH. Cyclic voltammetry and UV-visible absorption spectroscopy confirmed that the CuS in CuS@TiO2strongly withdraws the excited electrons from the valence band in TiO2because of the higher reduction potential than TiO2, resulting in a slower recombination rate between the electrons and holes and higher photoactivity.

scholarly journals Interaction of Manganese(II) with Proton Pump Inhibitor at Different pH: A Cyclic Voltammetric Study

2016 ◽  
Vol 64 (2) ◽  
pp. 115-120
Author(s):  
R Biswas ◽  
S Islam ◽  
MS Rahman ◽  
MA Haque ◽  
M Abu Hasan ◽  
...  
Keyword(s):  
Proton Pump ◽  
Suitable Condition ◽  
Acetate Buffer ◽  
Acetate Buffer Solution ◽  
Molar Ratio ◽  
Cyclic Voltammograms ◽  
Buffer Solution ◽  
Cyclic Voltammetric ◽  
Cyclic Voltammetric Study ◽  
Insight Into

The electrochemistry of Mn2+ at different pH (3.5-4.5) in acetate buffer solution has been investigated, using cyclic voltammetric method at glassy carbon electrode (GCE). Cyclic voltammograms (CVs) of Mn2+ show two cathodic and an anodic peaks over the entire investigated pH. The CVs of Mn2+ has also been performed in presence of proton pump inhibitors (PPIs) such as omeprazole, pantoprazole, esomeprazole and rabeprazole to elucidate the interaction of Mn2+ with the PPIs in acetate buffer solution. At the studied pH, a reasonably strong interaction was observed between Mn2+ and PPIs at different molar ratio of Mn2+ ion and PPIs. However, maximum interaction has been found at 1:2 molar ratio of Mn2+ and PPIs. This indicates the most suitable condition for the interaction between Mn2+ and PPIs. These results could allow insight into the interactions of metal ions with the PPIs. Dhaka Univ. J. Sci. 64(2): 115-120, 2016 (July)

scholarly journals Voltammetric study of the interactions of alkaline earth metal ions and melamine at different ph

2016 ◽  
Vol 27 (1) ◽  
pp. 39-50
Author(s):  
Farhana Haque ◽  
Afroza Khatun ◽  
PK Bakshi ◽  
AA Shaikh
Keyword(s):  
Metal Ions ◽  
Alkaline Earth ◽  
Earth Metal ◽  
Suitable Condition ◽  
Acetate Buffer ◽  
Acetate Buffer Solution ◽  
Molar Ratio ◽  
Alkaline Earth Metal ◽  
Buffer Solution ◽  
Alkaline Earth Metal Ions

The electrochemical redox behavior of alkaline earth metal ions at different pH in acetate buffer solution has been investigated using cyclic voltammetric method at gold disk electrode (GDE). In the entire studied pH (3.68-6.23), metal ions show two cathodic and an anodic peak. The method has also been employed to observe the interaction of metal ions with melamine in acetate buffer solution. At all pH, a reasonably strong interaction occurs between metal ions and melamine at different metal ions/melamine molar ratio. However, maximum interaction takes place at 1:4 molar ratios of metal ions and melamine at pH 6.23. This is possibly the most suitable condition for alkaline earth metal-melamine interaction.Bangladesh J. Sci. Res. 27(1): 39-50, June-2014

scholarly journals Voltammetric study of the interaction of Cu(II) with proton pump inhibitor at different pH

2015 ◽  
Vol 50 (3) ◽  
pp. 219-226
Author(s):  
R Biswas ◽  
MC Das ◽  
S Islam ◽  
MA Haque ◽  
AA Shaikh
Keyword(s):  
Proton Pump ◽  
Metal Ion ◽  
Acetate Buffer Solution ◽  
Molar Ratio ◽  
Cyclic Voltammograms ◽  
Buffer Solution ◽  
Cyclic Voltammetric ◽  
Voltammetric Study ◽  
Electrochemical Redox ◽  
Insight Into

The electrochemical redox behavior of transition metal ion, Cu(II) at different pH in acetate buffer solution has been investigated using cyclic voltammetric method at glassy carbon electrode (GCE). Cyclic voltammograms of Cu(II) show two cathodic and an anodic peaks those remain identical at various pH. The cyclic voltammetric response of the metal ion has been observed in presence of proton pump inhibitors (PPIs) such as omeprazole, pantoprazole, esomeprazole and rabeprazole at various proportions of metal ion and PPIs. The nature of cyclic voltammograms of Cu(II) has been changed dramatically in presence of the PPIs due to the strong interaction between metal ion and PPIs. Almost similar interaction was noticed for all the PPIs. However, the maximum interaction was found at 1:2 molar ratio of Cu(II) and PPIs. The result could provide deep insight into the interaction between various metal ions and the PPIs that have been taken quite regularly in human bodyBangladesh J. Sci. Ind. Res. 50(3), 219-226, 2015

scholarly journals Effect of Molar Ratio on Structural and Size of ZnO/C Nanocomposite Synthesized Using a Colloidal Method at Low Temperature

2019 ◽  
Vol 19 (2) ◽  
pp. 422
Author(s):  
Siham Lhimr ◽  
Saidati Bouhlassa ◽  
Saidati Bouhlassa ◽  
Saidati Bouhlassa ◽  
Bouchaib Ammary ◽  
...  
Keyword(s):  
Room Temperature ◽  
Optical Band Gap ◽  
Hexagonal Wurtzite Structure ◽  
Molar Ratio ◽  
X Ray Diffraction ◽  
Visible Absorption ◽  
X Ray ◽  
Colloidal Method ◽  
Uv Visible ◽  
Diffraction Patterns

In this paper we study the effects of different molar ratio R of Zn2+ to OH– (R= nOH–/nZn(II) of the precursor was investigated by varying the amount of NaOH. Samples have been synthesized by the colloidal method at room temperature using (ZnCl2), citric acid (C6H8O9·H2O) and sodium hydroxide (NaOH). The formation of ZnO/C composite was characterized by The X-ray diffraction patterns indicated a high crystallinity and nanocrystalline size of ZnO with hexagonal wurtzite structure. The morphologies of the particles have been studied with a scanning electronic microscopy (SEM). The existence of carbon into the composite was detected by FTIR and EDS. The optical band gap of various ZnO/C composite was calculated from UV-Visible absorption measurement varied in the range 3.301 to 3.282 eV according to R values.

scholarly journals Chemical Synthesis, Spectral Characterization and Antitumor Activity of Co(II), Zn(II) and Ni(II) Complexes Derived from Thiazole-based Schiff Base Ligand

2021 ◽  
Vol 10 (3) ◽  
pp. 2546-2556
Keyword(s):  
Schiff Base ◽  
Metal Complexes ◽  
Schiff Base Ligand ◽  
Molecular Structures ◽  
Schiff Base Complexes ◽  
Molar Ratio ◽  
Visible Absorption ◽  
Ic50 Values ◽  
Ft Ir ◽  
Uv Visible

The present study deals with the synthesis of a new Schiff base ligand, 4-(((4-chlorobenzo[d]thiazol-2-yl)imino)methyl)-2-methoxyphenol (HL) derived from the condensation of 2-Amino-4-chlorobenzothiazole and 4-Hydroxy-3-methoxybenzaldehyde, and its Co(II), Zn(II) and Ni(II) complexes in 2:1 molar ratio (2HL:M). The Schiff base ligand and its metal complexes were characterized using FT-IR, UV-Visible absorption, mass spectra, and TGA techniques. The spectral analysis results confirmed the molecular structures of the Schiff base ligand and its metal complexes. Further, the metallic Schiff base complexes showed significant growth inhibition in the adenocarcinoma human alveolar basal epithelial cells, A549, with the Co(II), Zn(II), and Ni(II) complexes having IC50 values of 40.78, 42.04, and 44.69 M, respectively.

scholarly journals Cyclic Voltammetric Study of the Interaction of Biologically Important Metal Ion with Proton Pump Inhibitors

2016 ◽  
Vol 64 (1) ◽  
pp. 25-30
Author(s):  
Milton C Das ◽  
Rajib Biswas ◽  
Humaiara Akter ◽  
MA Haque ◽  
PK Bakshi ◽  
...  
Keyword(s):  
Proton Pump Inhibitors ◽  
Proton Pump ◽  
Metal Ion ◽  
Acetate Buffer Solution ◽  
Molar Ratio ◽  
Cathodic Peak ◽  
Buffer Solution ◽  
Cyclic Voltammetric ◽  
Cyclic Voltammetric Study ◽  
Voltammetric Study

Electrochemical studies on the interaction of Fe(III) with proton pump inhibitors (PPIs) (omeprazole, pantoprazole, esomeprazole and rabeprazole) in acetate buffer solution were carried out at gassy carbon electrode (GCE) at various pH (3.5, 4.0 and 4.5). In presence of omeprazole (Ome), the anodic and cathodic peak current for Fe(III) decreased in comparison to solely Fe(III). However, in some cases both the peaks were almost disappeared. Moreover, anodic and cathodic peaks shifted significantly towards negative potential. This is an indication that a strong interaction occurred between Fe(III) and Ome. The maximum interaction is found at 1:2 molar ratio of Fe(III) and Ome at above mentioned pH. The electrochemical interaction of Fe(III) and other PPIs was found as identical with the behavior of Ome. The electrochemical study of the interactions between metal ions and PPIs would provide important information for the technological application of PPIs in human body.Dhaka Univ. J. Sci. 64(1): 25-30, 2016 (January)

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