The deprotonation and regioselective reaction of 2H-pyrazolo[3,4-c]quinolines with a variety of electrophiles is described. Electrophiles include benzaldehyde, DMF, carbon dioxide, and iodine. This method provides a direct route to a class of pharmacologically interesting compounds. 相似文献
Ultra-performance liquid chromatography coupled to tandem mass spectrometry (UPLC–MS–MS) has been used for screening and quantification
of 32 pesticides and metabolites in two fruit matrices. The compounds investigated belonged to different chemical families
of insecticides, acaricides, fungicides, and herbicides; several metabolites were also included. Quantification was conducted
using matrix-matched standards calibration; response was a linear function of concentration in the range tested (10–500 ng
mL−1). The method was validated with blank samples of lemon and raisin spiked at 0.01 and 0.1 mg kg−1, and recoveries were satisfactory, between 70 and 110%, for most of the pesticides tested and relative standard deviations
were below 15% (n = 5 at each spiking level). Excellent sensitivity resulted in limits of detection for all compounds well below 0.01 mg kg−1, with the limit of quantification being validated at 0.01 mg kg−1. The UPLC system generates narrow peaks (approx. 5 s), thus increasing peak height and improving sensitivity. This improved
separation efficiency facilitates adequate resolution not only of the analytes but also of matrix interferences compared with
conventional HPLC. The method developed could also resolve some geometric isomers. The main advantage of this approach is
the high sample throughput achieved because of the short analysis time, which enables satisfactory separation of all the compounds
in less than 5 min per sample. 相似文献
TFA has been widely used as a cleaving reagent in solid-phase organic synthesis. However, it is difficult to remove from the final product, and it is toxic to various cells. To search for an alternative, we studied the kinetics of HCl cleavage reactions of 18 resin-bound compounds on various linkers. HCl is very easy to remove completely from samples, and the residual HCl does not have a toxic effect in cell assays. Most compounds studied in this work can be easily cleaved using a low concentration of HCl (0.9-2.3%) and the minimal amount of time (60-90 min). Even in the most difficult case, a moderate 8% HCl and an extended time (10-15 h) are enough to cleave the product. Therefore, our kinetic studies establish HCl as a biocompatible, removable, and effective substitute for TFA when final compounds are used for biological screening and drug discovery. 相似文献
Blocking the main replicating enzyme, 3 Chymotrypsin-like protease (3CLpro) is the most promising drug development strategy against the SARS-CoV-2 virus, responsible for the current COVID-19 pandemic. In the present work, 9101 drugs obtained from the drug bank database were screened against SARS-CoV-2 3CLpro prosing deep learning, molecular docking, and molecular dynamics simulation techniques. In the initial stage, 500 drug-screened by deep learning regression model and subjected to molecular docking that resulted in 10 screened compounds with strong binding affinity. Further, five compounds were checked for their binding potential by analyzing molecular dynamics simulation for 100 ns at 300 K. In the final stage, two compounds {4-[(2s,4e)-2-(1,3-Benzothiazol-2-Yl)-2-(1h-1,2,3-Benzotriazol-1-Yl)-5-Phenylpent-4-Enyl]Phenyl}(Difluoro)Methylphosphonic Acid and 1-(3-(2,4-dimethylthiazol-5-yl)-4-oxo-2,4-dihydroindeno[1,2-c]pyrazol-5-yl)-3-(4-methylpiperazin-1-yl)urea were screened as potential hits by analyzing several parameters like RMSD, Rg, RMSF, MMPBSA, and SASA. Thus, our study suggests two potential drugs that can be tested in the experimental conditions to evaluate the efficacy against SARS-CoV-2. Further, such drugs could be modified to develop more potent drugs against COVID-19.
The ability to tune the physical properties of bistable organic functional materials by means of chemistry can facilitate their development for molecular electronic switching components. The butylamine-containing biphenalenyl boron neutral radical, [Bu]2B, crystalline compound has recently attracted significant attention by displaying a hysteretic phase transition accompanied by simultaneous bistability in magnetic, electrical, and optical properties close to room temperature. In this report, substitutional doping was applied to [Bu]2B by crystallizing solid solutions of bistable [Bu]2B and its non-radical-containing counterpart [Bu]2Be. With increasing doping degree, the hysteretic phase transition is gradually suppressed in terms of reducing the height, but conserves the width of the hysteresis loop as observed through magnetic susceptibility and electrical conductivity measurements. At the critical doping level of about 6 %, the abrupt transformation of the crystal structure to that of the pure [Bu]2Be crystal packing was observed, accompanied by a complete collapse of the hysteresis loop. Further study of the structure–properties relationships of bistable neutral radical conductors based on the [Bu]2B host can be conducted utilizing a variety of biphenalenyl-based molecular conductors. 相似文献
Journal of Radioanalytical and Nuclear Chemistry - This study describes a rapid and novelty method for radiostrontium determination in aerosol filters and vegetation based on the use of plastic... 相似文献