Succinimide Derivatives as Acetylcholinesterase Inhibitors-In Silico and In Vitro Studies.

We studied the effect of succinimide derivatives on acetylcholinesterase activity due to the interest in compounds that influence this enzyme's activity, which could help treat memory issues more effectively. The following parameters were established for this purpose based on kinetic investigations of the enzyme in the presence of succinimide derivatives: the half-maximal inhibitory concentration, the maximum rate, the inhibition constant, and the Michaelis-Menten constant. Furthermore, computational analyses were performed to determine the energy required for succinimide derivatives to dock with the enzyme's active site. The outcomes acquired in this manner demonstrated that all compounds inhibited acetylcholinesterase in a competitive manner. The values of the docking energy parameters corroborated the kinetic parameter values, which indicated discernible, albeit slight, variations in the inhibitory intensity among the various derivatives.

Methodological Principles of Nasal Food Challenge.

Thanks to their valuable assessment possibilities (subjective complaints and changes in nasal patency during the examination), nasal provocation tests may serve as an alternative tool for oral food challenges in the future. However, this test requires successive attempts to regulate its methodology in order to develop a standardized lyophilisate form and determine the threshold dose for a positive result. The study objective was to present the methodological foundation for nasal food allergen provocation tests induced by freeze-dried powdered chicken egg whites. A control group of 25 individuals with no history of allergy to chicken eggs or any other allergy was included in the study. Optical rhinometry and visual analog scales were used to assess the response of nasal mucosa to local allergen challenges. Minor variations in nasal flows, as measured by optical rhinometry, were observed in the provocation tests. The mean optical density measurements (as measured regardless of the allergen dose used) varied from positive to negative values and vice versa, e.g., amounting to 0.018 OD (standard deviation 0.095) at 15 min and -0.011 OD (standard deviation 0.090) at 30 min. No significant differences were observed concerning the perceived nasal discomfort using the visual analog scale. Due to the absence of nasal mucosal reactivity, nasal challenge is an excellent methodological tool for implementing food allergen tests.

Nonaqueous Capillary Electrophoretic Separation of Analogs of (24R)-1,24-Dihydroxyvitamin D3 Derivative as Predicted by Quantum Chemical Calculations.

Nonaqueous capillary electrophoretic (NACE) separation was obtained of analogs of (24R)-1,24-dihydroxyvitamin D3 derivative (calcipotriol) as predicted by quantum chemical calculations supported by the density functional theory (DFT). Among the key electronic properties investigated, absolute values of the dipole polarizability and energy gap between HOMO and LUMO molecular orbitals of the analog molecules differ significantly for particular analogs, and there is a direct relationship with their electrophoretic migration time. These differences and relationships suggest that the structurally related analogs should be separable in the electrostatic field. Indeed, the robust, sensitive, and rapid NACE method was first developed for the identification and determination of the anticancer analog of calcipotriol (coded PRI-2205) and its process-related impurities (coded PRI-2201, PRI-2203, and PRI-2204) in organic and aqueous biological solutions. The direct relation between the calculated electronic properties of the analogs and the experimental electrophoretic migration time could be a promising prospect for theoretically predicting the electrophoretic separations.

Catalase Inhibition by Aminoalkanol Derivatives with Potential Anti-Cancer Activity-In Vitro and In Silico Studies Using Capillary Electrophoresis Method.

In this work, the investigation of type and inhibitory strength of catalase by two pairs of aminoalkanol derivatives (1,7 diEthyl- and 1,7-diMethyl-8,9-diphenyl-4-azatricyclo (5.2.1.02.6) dec-8-ene- 3,5,10-trione) has been presented. The obtained results allowed for the determination of all kinetic parameters (Km, Vmax, slope angles of Lineweaver-Burk plots, Ki and IC50) on the basis of which it was shown that all four aminoalkanol derivatives are competitive inhibitors of catalase. However, the strength of action of each of them depends on the type of substituents present in the main structure of the molecule. Subtle differences in the potency of individual derivatives were possible to detect thanks to the developed, sensitive method of capillary electrophoresis, which allowed simultaneous monitoring of the mutual changes in the concentrations of substrates and products of the reaction catalyzed by the enzyme. Detailed values of kinetic parameters showed that all derivatives are weak inhibitors of catalase, which in this case is a big advantage because each inhibition of catalase activity is associated with a greater amount of accumulated, harmful reactive oxygen species. The results of docking studies also show the convergence of the binding energies values of individual inhibitors with all kinetic parameters of the investigated catalase inhibition and thus additionally confirm the weak inhibitory strength of all four aminoalkanol derivatives.

Kinetic Studies of Newly Patented Aminoalkanol Derivatives with Potential Anticancer Activity as Competitive Inhibitors of Prostate Acid Phosphatase.

BACKGROUND: Acid phosphatase and its regulation are important objects of biological and clinical research and play an important role in the development and treatment of prostate and bone diseases. The newly patented aminoalkanol (4-[2-hydroxy-3-(propan-2-ylamino)propyl]-1,7-dimethyl-8,9-diphenyl-4-azatricyclo[5.2.1.02,6]dec-8-ene-3,5,10-trione hydrochloride) (I) and (4-[3-(dimethylamino)-2-hydroxypropyl]-1,7-dimethyl-8,9-diphenyl-4-azatricyclo[5.2.1.02,6]dec-8-ene-3,5,10-trione hydrochloride) (II) derivatives have potential anticancer activity, and their influence on enzymatic activity can significantly impact the therapeutic effects of acid phosphatase against many diseases. Therefore, in this study, we investigated the action of compounds (I) and (II) on acid phosphatase. METHODS: Capillary electrophoresis was used to evaluate the inhibition of acid phosphatase. Lineweaver-Burk plots were constructed to compare the Km of this enzyme in the presence of inhibitors (I) or (II) with the Km in solutions without these inhibitors. RESULTS: Compound (I) showed a stronger competitive inhibition against acid phosphatase, whereas derivative (II) showed a weaker competitive type of inhibition. The detailed kinetic studies of these compounds showed that their type and strength of inhibition as well as affinity depend on the kind of substituent occurring in the main chemical molecule. CONCLUSIONS: This study is of great importance because the disclosed inhibition of acid phosphatase by compounds (I) and (II) raises the question of whether these compounds could have any effect on the treatment possibilities of prostate diseases.

Dual 2-Hydroxypropyl-ß-Cyclodextrin and 5,10,15,20-Tetrakis (4-Hydroxyphenyl) Porphyrin System as a Novel Chiral-Achiral Selector Complex for Enantioseparation of Aminoalkanol Derivatives with Anticancer Activity in Capillary Electrophoresis.

In this study, a complex consisting of 2-hydroxypropyl-ß-cyclodextrin and 5,10,15,20-tetrakis (4-hydroxyphenyl) porphyrin, (named dual chiral-achiral selector complex) was used for the determination of two novel potential anticancer agents of (I) and (II) aminoalkanol derivatives. This work aimed at developing an effective method that can be utilized for the determination of I (S), I (R), and II (S) and II (R) enantiomers of (I) and (II) compounds through the use of a dual chiral-achiral selector complex consisting of hydroxypropyl-ß-cyclodextrin and 5,10,15,20-tetrakis (4-hydroxyphenyl) porphyrin system by applying capillary electrophoresis. This combination proved to be beneficial in achieving high separation selectivity due to the combined effects of different modes of chiral discrimination. The enantiomers of (I) and (II) compounds were separated within a very short time of 3.6-7.2 min, in pH 2.5 phosphate buffer containing 2-hydroxypropyl-ß-cyclodextrin and 5,10,15,20-tetrakis (4-hydroxyphenyl) porphyrin system at a concentration of 5 and 10 mM, respectively, at 25 °C and +10 kV. The detection wavelength of the detector was set at 200 nm. The LOD for I (S), I (R), II (S), and II (R) was 65.2, 65.6, 65.1, and 65.7 ng/mL, respectively. LOQ for I (S), I (R), II (S), and II (R) was 216.5, 217.8, 217.1, and 218.1 ng/mL, respectively. Recovery was 94.9-99.9%. The repeatability and reproducibility of the method based on the values of the migration time, and the area under the peak was 0.3-2.9% RSD. The stability of the method was determined at 0.1-4.9% RSD. The developed method was used in the pilot studies for determining the enantiomers I (S), I (R), II (S), and II (R) in the blood serum.

In Vitro and In Silico Kinetic Studies of Patented 1,7-diEthyl and 1,7-diMethyl Aminoalkanol Derivatives as New Inhibitors of Acetylcholinesterase.

Two aminoalkanol derivatives of 1,7-diEthyl-8,9-diphenyl-4azatricyclo (5.2.1.02.6) dec-8-ene-3,5,10-trione and two derivatives of 1,7-diMethyl-8,9-diphenyl-4-azatricyclo (5.2.1.02.6) dec-8-ene-3,5,10-trione were evaluated in vitro for their inhibition efficacy of acetylcholinesterase. The Km, Vmax, slope angles of Lineweaver-Burk plots, Ki and IC50 values showed that all four aminoalkanol derivatives are competitive inhibitors of acetylcholinesterase whose inhibitory potency depends, to a varying extent, on the nature of the four different substituents present in the main compound structure. Studies have shown that the most potent acetylcholinesterase inhibitors are derivatives containing isopropylamine and/or methyl substituents in their structure. In contrast, dimethylamine and/or ethyl substituents seem to have a weaker, albeit visible, effect on the inhibitory potency of acetylcholinesterase. Additionally, docking studies suggest that studied compounds binds with the peripheral anionic site and not enter into the catalytic pocket due to the presence of the sterically extended substituent.

Capillary electrophoresis for the investigation of two novel aminoalkanol derivatives of 1,7-diethyl-8,9-diphenyl-4-azatricyclo[5.2.1.02,6] dec-8-ene-3,5,10-trione as potential anticancer drugs in water solution and serum.

A simple, rapid, capillary zone electrophoresis method was developed and validated for the analysis of two novel aminoalkanol derivatives (I) and (II) of 1,7-diethyl-8,9-diphenyl-4-azatricyclo[5.2.1.02,6 ]dec-8-ene-3,5,10-trione, which were found in earlier studies as potential anticancer drugs. Samples were analyzed to demonstrate the specificity and stability indicating ability of the developed method. The samples were extracted using n-hexane-ethyl acetate mixture in the ratio of 90:10. Electrophoretic separation was performed on a eCAP fused silica capillary (37 cm length, 50 µm inside diameter) with a 50 mM tetraborate buffer as a background electrolyte adjusted to pH = 2.5. The separation time of (I) and (II) was achieved within 7 min. In addition, analysis of the two compounds in the serum was conducted. Limits of detection of (I) and (II) by UV absorbance at 200 nm were achieved in the range of 87.4-92.1 ng/mL. The sufficient recovery was observed in the range of 90.3-99.8%. The quantification limits for the compounds (I) and (II) were in the range of 279.71-291.03 ng/mL, respectively. The method has been successfully applied to the analysis of compounds (I) and (II) in serum samples.

Characterization and inhibition studies of tissue nonspecific alkaline phosphatase by aminoalkanol derivatives of 1,7-dimethyl-8,9-diphenyl-4-azatricyclo[5.2.1.02,6]dec-8-ene-3,5,10-trione, new competitive and non-competitive inhibitors, by capillary electrophoresis.

The article describes the inhibitory effect of two new aminoalkanol derivatives on the enzymatic kinetic of tissue non-specific alkaline phosphatase with use of capillary zone electrophoresis to evaluate the inhibitory effect. This technique allows to investigate of the enzymatic kinetic by the measure of the amounts of the substrate and product in the presence of compound (I) or (II) in the reaction mixture. The separation process was conducted using an eCAP fused-silica capillary. The detector was set at 200nm. The best parameters for the analysis were: 25mM sodium dihydrogen phosphate adjusted to pH=2.5, temperature 25°C, and voltage -15kV. Lineweaver-Burk plots were constructed and determined by comparison of the Km, of alkaline phosphatase in the presence of inhibitor (I) or (II) with the Km in a solution without inhibitor. The influence of replacement the propylamine group by the dimethylamine group on tissue non-specific alkaline phosphatase inhibition activity of new derivatives (I) and (II) was investigated. The tested compounds (I) and (II) were found to be tissue non-specific alkaline phosphatase inhibitors. Detailed kinetic studies indicated a competitive mode of inhibition against tissue non-specific alkaline phosphatase for compound (I) and non-competitive mode of inhibition for compound (II).

Determination of the stereoisomers in aqueous medium and serum and validation studies of racemic aminoalkanol derivatives of 1,7-dimethyl-8,9-diphenyl-4-azatricyclo[5.2.1.0(2,6) ]dec-8-ene-3,5,10-trione, potential new anticancer drugs, by capillary electrophoresis.

A new method for the determination of the stereoisomers, in aqueous medium and serum, of the racemic aminoalkanol derivatives I and II of 1,7-dimethyl-8,9-diphenyl-4-azatricyclo[5.2.1.0(2,6) ]dec-8-ene-3,5,10-trione, which were found in earlier studies to be potential anticancer drugs, was developed and validated. The optimized conditions included 25 mM phosphate buffer adjusted to pH 2.5, containing γ-cyclodextrin at a concentration of 5% m/v, as background electrolyte, an applied voltage of +10 kV, and a temperature of 25°C. Separations were carried out using a fused-silica capillary. The developed method of determining the enantiomers of compounds I(S), I(R) and II(S), II(R) was characterized by the following parameters: a detection time within 10.8 min, a detection limit in the range of 141.2-141.7 ng/mL using the UV absorption detection at 200 nm. Good linearity (R(2) = 0.9989-0.9998) was achieved within the range of concentrations studied. A very good extraction yield of 95.4-99.7% was achieved, and recoveries were carried out from both aqueous solutions and matrix serum. The repeatability of the method for peak areas with an accuracy of the determined concentrations of the analytes in the range of 1.43-1.89%, and limits of quantitation in the range of 432.4-436.3 ng/mL were achieved.

Capillary electrophoresis separation of aminoalkanol derivatives of 1,7-dimethyl-8,9-diphenyl-4-azatricyclo[5.2.1.0(2,6)]dec-8-ene-3,5,10-trione as potential anticancer drugs.

The purpose of this study, the direct separation of aminoalkanol derivatives I and II of 1,7-dimethyl-8,9-diphenyl-4-azatricyclo[5.2.1.0(2,6) ]dec-8-ene-3,5,10-trione, which was found in earlier studies as potential anticancer drugs, were performed. Capillary electrophoresis offers the possibility of fast, cheap, and reproducible separations for compounds I and II. In this paper, the simultaneous separation of I and II by capillary zone electrophoresis has been achieved within 8 min by use of 50 mM phosphate buffer of pH 2.5. Analysis of the two compounds in the serum plasma standards was conducted. Limits of detection of I and II by UV absorbance at 200 nm were achieved in the range of 156.3-156.6 ng/mL. The method was validated for linearity, accuracy, precision, limits of detection, and quantification. The calibration equation revealed a good linear relationship (r(2) = 0.998-0.999). Sufficient recovery was observed in the range of 96.3-99.5%. The method showed good reproducibility with intra- and interday precision of 0.97 and 1.76%, respectively. The quantification limits for the compounds were in the range of 477.0-479.8 ng/mL. The proposed method was applied to the analysis of real serum samples.

[Enantiomers: a new problem in pharmacotherapy of depression?]. / Enancjomery: nowy problem w farmakoterapii depresji?

Enantiomers as a optically active forms of drugs now have a big impact on most areas of pharmacotherapy. They arouse a large interest in the field of psychiatry and especially in the treatment of depression. This is due to the fact that enantiomers (chiral forms) of many drugs may have a different pharmacokinetic, pharmacological or pharmacogenetic profiles. Therefore, in many cases the use of a single enantiomer of the drug may have huge advantages over previously used forms and lead to strong improvement of the current treatments. An example is the stereoselective property of such a psychotropic drug fluoxetine as belonging to a group of selective serotonin reuptake inhibitors (SSRI).

A simpler and faster capillary electrophoresis method for determination of mianserin enantiomers in human serum.

A stereospecific sample stacking capillary zone electrophoresis method is described for determination of S(+) and R(-) enantiomers of mianserin (1,2,3,4,10,14b-hexahydro-2-methyldibenzo[c,f]pyrazino[1,2-a]azepine) in human serum. The enantiomers of mianserin were extracted from human serum in one step extraction procedure using the mixture n-heptane:ethyl acetate (80:20, v/v). After separation of layers and freezing at -28 degrees C the organic layer was decanted and evaporated under a stream of nitrogen. The sample was dissolved in the mixture: water:methanol:acetonitrile (2:1:1, v/v/v). Separation was conducted in an aqueous solution of phosphoric acid (0.075M) adjusted to pH = 3.0 with concentrated triethylamine, and 2 mmole/L of 2-hydroxypropyl-beta-cyclodextrin. The analytes were measured by ultraviolet detection at 214 nm after separation on a Fused-Silica eCAP capillary. Clozapine was used as an internal standard. Recovery of the enantiomers from serum ranged from 82.94 to 90.37%. Total time of analysis was 49 minutes, whereas the other methods needed up to 100 minutes.