The structure-based design of some CDK2 inhibitors with a 3-(benzylidene)indolin-2-one scaffold as potential anticancer agents was realized. Target compounds were obtained as E/Z mixtures and were resolved to corresponding E- and Z-diastereomers. In silico studies using MOE 2019.01 software revealed better docking on the targeted enzyme for the Z-diastereomer compared to the E-one. A time-dependent kinetic isomerization study was carried out for the inversion of E/Z diastereomers in DMSO-d6 at room temperature, and were found to obey the first order kinetic reactions. Furthermore, a determination of the kinetic inter-conversion rate order by graphical analysis method and calculation of the rate constant and half-life of this kinetic process were carried out. For the prediction of the stability of the diastereomer(s), a good multiple regression equation was generated between the reaction rates of isomerization and some QM parameters with significant p value.

The structure-based design of some CDK2 inhibitors with a 3-(benzylidene)indolin-2-one scaffold as potential anticancer agents was realized. Target compounds were obtained as E/Z mixtures and were resolved to corresponding E- and Z-diastereomers. In silico studies using MOE 2019.01 software revealed better docking on the targeted enzyme for the Z-diastereomer compared to the E-one. A time-dependent kinetic isomerization study was carried out for the inversion of E/Z diastereomers in DMSO-d6 at room temperature, and were found to obey the first order kinetic reactions. Furthermore, a determination of the kinetic inter-conversion rate order by graphical analysis method and calculation of the rate constant and half-life of this kinetic process were carried out. For the prediction of the stability of the diastereomer(s), a good multiple regression equation was generated between the reaction rates of isomerization and some QM parameters with significant p value.

Herein, a rational combination of dispersive solid-phase sorbent and 2-(2, 4-Dihydroxyphenyl)-3, 5, 7-trihydroxychromen-4-one (morin) was proposed for sensitive and selective determination of Al3+ ion. Nickel ferrite nanospheres (NiFe2O4 NS) functionalized with morin was used to preconcentrate and estimate Al3+ via the formation of fluorescent complex at pH 7.0. The functionalization was assisted by anionic surfactant sodium dodecyl sulphate (SDS) and ultrasonication. The results revealed that the fluorescence intensity of Al-morin/SDS@ NiFe2O4 NS is higher than Al-morin. Functionalization of NiFe2O4 NS with morin was confirmed by scanning electron microscopy (SEM), transmission electron microscopy (TEM), energy-dispersive X-ray spectroscopy (EDX), Fourier transform infrared spectroscopy (FTIR), powder X-ray diffractometer (PXRD), and fluorescence spectroscopy. Under the optimum conditions, the fluorescence intensity increased with increasing of Al3+ concentrations in the range of 0.28–500.0 ng mL−1 with LOD (S/N = 3) of 0.09 ng mL−1. The method was applied for the determination of Al3+ in natural waters and human serum samples with recoveries % of 97–104% and RSDs % of 2–4%.

Herein, a rational combination of dispersive solid-phase sorbent and 2-(2, 4-Dihydroxyphenyl)-3, 5, 7-trihydroxychromen-4-one (morin) was proposed for sensitive and selective determination of Al3+ ion. Nickel ferrite nanospheres (NiFe2O4 NS) functionalized with morin was used to preconcentrate and estimate Al3+ via the formation of fluorescent complex at pH 7.0. The functionalization was assisted by anionic surfactant sodium dodecyl sulphate (SDS) and ultrasonication. The results revealed that the fluorescence intensity of Al-morin/SDS@ NiFe2O4 NS is higher than Al-morin. Functionalization of NiFe2O4 NS with morin was confirmed by scanning electron microscopy (SEM), transmission electron microscopy (TEM), energy-dispersive X-ray spectroscopy (EDX), Fourier transform infrared spectroscopy (FTIR), powder X-ray diffractometer (PXRD), and fluorescence spectroscopy. Under the optimum conditions, the fluorescence intensity increased with increasing of Al3+ concentrations in the range of 0.28–500.0 ng mL−1 with LOD (S/N = 3) of 0.09 ng mL−1. The method was applied for the determination of Al3+ in natural waters and human serum samples with recoveries % of 97–104% and RSDs % of 2–4%.

Herein, yellow emissive nitrogen doped graphene quantum dots (N@GQDs) were prepared by a novel advanced thermal driven oxidation. The N@GQDs was functionalized with β-cyclodextrin (β-CD) to improve its catalytic performance towards dopamine (DA) detection. The β-CD/N@GQDs exhibited strong fluorescence at λem. = 550 nm after excitation at 460 nm with a quantum yield of 38.6%. The β-CD/N@GQDs showed good peroxidase like activity via catalyzing the oxidation of tetramethylbenzidine (TMB) in presence of H2O2 to form blue colored product at λmax = 652 nm. In the colorimetric assay of DA, the detection based on the oxidation of TMB by H2O2 in presence of β-CD/N@GQDs as a catalyst. Then, the color of the blue oxidized TMB (oxTMB) product was reduced by addition of DA. While the fluorometric detection of DA based on the “inner filter effect” of the overlapped emission spectrum of β-CD/N@GQDs with the absorption spectrum of oxTMB, where, addition of DA reduces oxTMB to TMB and restores the fluorescence intensity of β-CD/N@GQDs. Under the optimized conditions, the colorimetric method achieved linearity range of 0.12–7.5 µM and LOD (S/N = 3) of 0.04 µM, while the fluorometric method achieved linearity range of 0.028–1.5 µM and LOD (S/N = 3) of 0.009 µM. The peroxidase like activity of β-CD/N@GQDs was used to detect DA in human plasma and serum samples with good % recoveries. The colorimetric and fluorometric methods exhibited good sensitivity and selectivity toward DA detection.

Herein, poly (dopamine- Cr3+) nanocubes functionalized reduced graphene oxide ((poly (DAQ-Cr3+) @ rGO)) nanohybrid was proposed for electrochemical determination of flibanserin (FLBN). The poly (DAQ-Cr3+) and poly (DAQ-Cr3+)@ rGO nanohybrids were characterized via different morphological and spectroscopic techniques such as scanning electron microscope (SEM), transmission electron microscope (TEM), energy dispersive X-ray spectroscopy (EDX), Fourier transform infrared (FTIR) spectroscopy, electrochemical impedance spectroscopy (EIS) and cyclic voltammetry (CV). The modified electrode exhibited high electro- catalytic activity towards the electrochemical oxidation of FLBN in phosphate buffer solution (PBS, pH 6.0). Using DPV technique, the anodic oxidation peak current (Ipa) was increased with the increase of FLBN concentration in the range of 0.05–25.0 × 10−7 M with LOD of 0.016 × 10−7 M. Moreover, the poly (DAQ-Cr3+) @ rGO/GCE was successfully applied for analysis of FLBN in human plasma and urine samples.

Herein, poly (dopamine- Cr3+) nanocubes functionalized reduced graphene oxide ((poly (DAQ-Cr3+) @ rGO)) nanohybrid was proposed for electrochemical determination of flibanserin (FLBN). The poly (DAQ-Cr3+) and poly (DAQ-Cr3+)@ rGO nanohybrids were characterized via different morphological and spectroscopic techniques such as scanning electron microscope (SEM), transmission electron microscope (TEM), energy dispersive X-ray spectroscopy (EDX), Fourier transform infrared (FTIR) spectroscopy, electrochemical impedance spectroscopy (EIS) and cyclic voltammetry (CV). The modified electrode exhibited high electro- catalytic activity towards the electrochemical oxidation of FLBN in phosphate buffer solution (PBS, pH 6.0). Using DPV technique, the anodic oxidation peak current (Ipa) was increased with the increase of FLBN concentration in the range of 0.05–25.0 × 10−7 M with LOD of 0.016 × 10−7 M. Moreover, the poly (DAQ-Cr3+) @ rGO/GCE was successfully applied for analysis of FLBN in human plasma and urine samples.

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