Improvement in dye sensitized solar cells from past to present

Several emerging renewable technologies are available to satisfy the current energy demand and to minimize the effect of environmental degradation caused by high consumption of fossil fuels. These technologies are not mature enough to solve this problem but require more time for improving the efficiency, and cost reduction to become the economical alternative of fossil fuels. In this paper Dye-sensitized solar cell (DSSC) has been discussed in detail owing to advancement in the technology. Since each component of DSSC is responsible for a specific function, therefore, comprehensive literature studies has been done on individual section to understand the technology in depth. All the advancement in sensitizer, semiconductors, electrolyte, electrodes, additives, sealing and anchoring groups are included in this review with performance parameter of DSSC. Focus of this article is to provide summary of all available literature since beginning to date.     

A spectrophotometric method for quantitative determination of lactulose in pharmaceutical preparations

A simple spectrophotometric assay for the quantification of lactulose in pharmaceutical preparations was developed. The method is based on hydrolysis of lactulose under acidic conditions. The hydrolyzed product reacts with resorcinol, giving absorption peaks at 398 and 480 nm. Both absorption wavelengths can be used for the determination of lactulose. The limit of detection of lactulose at 398 nm and 480 nm was 0.075 μg mL⁻¹ and 0.65 μg mL⁻¹, respectively. The calibration was linear in the range of 5–25 μg mL⁻¹. Analytical conditions were optimized, and the method was validated for analysis of pharmaceutical preparations. The determined amount of lactulose was found to be in good agreement with labeled claims in commercial products. The proposed method is economical, convenient, and suitable for the quantification of lactulose in pharmaceutical preparations. The text was submitted by the authors in English.     

Development and Validation of a Chiral Liquid Chromatographic Assay for Enantiomeric Separation and Quantification of Verapamil in Rat Plasma: Stereoselective Pharmacokinetic Application

A novel, fast and sensitive enantioselective HPLC assay with a new core–shell isopropyl carbamate cyclofructan 6 (superficially porous particle, SPP) chiral column (LarihcShell-P, LSP) was developed and validated for the enantiomeric separation and quantification of verapamil (VER) in rat plasma. The polar organic mobile phase composed of acetonitrile/methanol/trifluoroacetic acid/triethylamine (98:2:0.05: 0.025, v/v/v/v) and a flow rate of 0.5 mL/min was applied. Fluorescence detection set at excitation/emission wavelengths 280/313 nm was used and the whole analysis process was within 3.5 min, which is 10-fold lower than the previous reported HPLC methods in the literature. Propranolol was selected as the internal standard. The S-(−)- and R-(+)-VER enantiomers with the IS were extracted from rat plasma by utilizing Waters Oasis HLB C18 solid phase extraction cartridges without interference from endogenous compounds. The developed assay was validated following the US-FDA guidelines over the concentration range of 1–450 ng/mL (r² ≥ 0.997) for each enantiomer (plasma) and the lower limit of quantification was 1 ng/mL for both isomers. The intra- and inter-day precisions were not more than 11.6% and the recoveries of S-(−)- and R-(+)-VER at all quality control levels ranged from 92.3% to 98.2%. The developed approach was successfully applied to the stereoselective pharmacokinetic study of VER enantiomers after oral administration of 10 mg/kg racemic VER to Wistar rats. It was found that S-(−)-VER established higher C_max and area under the concentration-time curve (AUC) values than the R-(+)-enantiomer. The newly developed approach is the first chiral HPLC for the enantiomeric separation and quantification of verapamil utilizing a core–shell isopropyl carbamate cyclofructan 6 chiral column in rat plasma within 3.5 min after solid phase extraction (SPE).     

Design,synthesis and molecular docking of new [1,2,4] triazolo[4,3-a]quinoxaline derivatives as anticancer agents targeting VEGFR-2 kinase

Molecular Diversity - Vascular endothelial growth factor receptor-2 (VEGFR-2) is critically involved in cancer angiogenesis. Blocking of VEGFR-2 signaling pathway proved effective suppression of...     

Molecular Docking and Dynamics Simulation of Natural Compounds from Betel Leaves (Piper betle L.) for Investigating the Potential Inhibition of Alpha-Amylase and Alpha-Glucosidase of Type 2 Diabetes

Piper betle L. is widely distributed and commonly used medicinally important herb. It can also be used as a medication for type 2 diabetes patients. In this study, compounds of P. betle were screened to investigate the inhibitory action of alpha-amylase and alpha-glucosidase against type 2 diabetes through molecular docking, molecular dynamics simulation, and ADMET (absorption, distribution, metabolism, excretion, and toxicity) analysis. The molecule apigenin-7-O-glucoside showed the highest binding affinity among 123 (one hundred twenty-three) tested compounds. This compound simultaneously bound with the two-target proteins alpha-amylase and alpha-glucosidase, with high molecular mechanics-generalized born surface area (MM/GBSA) values (ΔG Bind = −45.02 kcal mol⁻¹ for alpha-amylase and −38.288 for alpha-glucosidase) compared with control inhibitor acarbose, which had binding affinities of −36.796 kcal mol⁻¹ for alpha-amylase and −29.622 kcal mol⁻¹ for alpha-glucosidase. The apigenin-7-O-glucoside was revealed to be the most stable molecule with the highest binding free energy through molecular dynamics simulation, indicating that it could compete with the inhibitors’ native ligand. Based on ADMET analysis, this phytochemical exhibited a wide range of physicochemical, pharmacokinetic, and drug-like qualities and had no significant side effects, making them prospective drug candidates for type 2 diabetes. Additional in vitro, in vivo, and clinical investigations are needed to determine the precise efficacy of drugs.     

Elucidating the Glucokinase Activating Potentials of Naturally Occurring Prenylated Flavonoids: An Explicit Computational Approach

Glucokinase activators are considered as new therapeutic arsenals that bind to the allosteric activator sites of glucokinase enzymes, thereby maximizing its catalytic rate and increasing its affinity to glucose. This study was designed to identify potent glucokinase activators from prenylated flavonoids isolated from medicinal plants using molecular docking, molecular dynamics simulation, density functional theory, and ADMET analysis. Virtual screening was carried out on glucokinase enzymes using 221 naturally occurring prenylated flavonoids, followed by molecular dynamics simulation (100 ns), density functional theory (B3LYP model), and ADMET (admeSar 2 online server) studies. The result obtained from the virtual screening with the glucokinase revealed arcommunol B (−10.1 kcal/mol), kuwanon S (−9.6 kcal/mol), manuifolin H (−9.5 kcal/mol), and kuwanon F (−9.4 kcal/mol) as the top-ranked molecules. Additionally, the molecular dynamics simulation and MM/GBSA calculations showed that the hit molecules were stable at the active site of the glucokinase enzyme. Furthermore, the DFT and ADMET studies revealed the hit molecules as potential glucokinase activators and drug-like candidates. Our findings suggested further evaluation of the top-ranked prenylated flavonoids for their in vitro and in vivo glucokinase activating potentials.