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Green and sensitive spectrofluorometric methods have been developed and validated for the determination of timolol maleate (TML)/hydrochlorothiazide (HCT) and amiloride hydrochloride (AMH)/hydrochlorothiazide in tablets. The proposed spectrofluorometric procedures were found to be linear in the range of 4–12, 5–35 and 0.025–0.2 mg L−1 for HCT, TML and AMH, resp. The excitation and emission wavelengths for HCT, TML and AMH at room temperature were 270 and 375, 295 and 435, 330 and 415 nm, resp. The methods were validated with respect to ICH guidelines. The AMH showed higher sensitivity with lower values of LOD and LOQ values compared to HCT and TML. The proposed methods were applied to two pharmaceutical formulations; the method for HCT and AMH has proven as reliable assaying method, whereas the method for TML, when combined with HCT, is applicable to screening semi-quantitative analyses.

Two active coronaviral proteins (3CLpro and Nsp15) have been studied using both the GCMS and docking methods. These coronaviral proteins have been examined with the methanol extract generated from leaves of the Arum palaestinum. According to the GC-MS findings, 19 major natural compounds are present in the plant's methanolic extract. The lowest Binding Energy (LBE) and the inhibition constant (Ki) have been used to identify and classify the potential of these lead drugs with their pharmacological properties. The affinity of these compounds with coronaviral proteins has been evaluated to reveal the usage of these compounds at the active sites of the receptors, 3CLpro (PDB ID: 6LU7) and Nsp15 (PDB ID: 6VWW). The results of β-Sitosterol, Androstan-3-one, Phenobarbital, Maltose, and α-Tocopherol show more affinity to Nsp15 and 3CLpro than to the supporting control drugs. Furthermore, an evaluation of the interactions of these components with the amino acids of 3CLpro and Nsp15 revealed that β-Sitosterol has the best LBE score and Ki value as compared with those of the approved medication and all other compounds under investigation. Consequently, these potential compounds may be modern inhibitors of coronavirus. Further in vitro and in vivo studies are needed for such computational findings. [ABSTRACT FROM AUTHOR]

The design and operation of an atmospheric pressure static reactor coupled to an ion trap mass spectrometer is described. The reactor is designed for studying gas-phase reactions that are important in atmospheric chemistry. The system provides a simple and robust method for identifying the products of gas-phase reactions. Results for the reaction of [O.sub.3] with 2,3-dimethyl-2-butene (tetramethylethylene, TME) are demonstrated as a proof of the principle for the performance of the static reactor. All of the previously reported major primary products of the reaction were observed, and the yields of two compounds (acetone and hydroxyacetone) were quantified, in excellent agreement with previous work. Several minor species were also observed, demonstrating the potential for this method to investigate the product channels for less well-studied atmospherically relevant reactions. Key words: atmospheric pressure reactor, ozone, tetramethylethylene (TME), ion trap mass spectrometer, gas-phase reaction. On decrit la fabrication et l'operation d'un reacteur statique a pression atmospherique coupleeea un spectrometre de masse avec trappe ionique. Le reacteur a ete construit de facon a pouvoir etudier les reactions en phase gazeuse importantes en chimie de l'atmosphere. Le systeme fournit une methode simple et robuste pour identifier les produits des reactions en phase gazeuse. On a utilise les resultats de la reaction de l'ozone, [O.sub.3,] avec le 2,3-dimethylbut-2-ene (tetramethylethylene, TME) comme preuve du principe de la performance du reacteur statique. Tous les produits primaires majeurs de la reaction rapportes anterieurement ont ete observes et les rendements de deux composes (acetone et hydroxyacetone) ont ete quantifies, en excellent accord avec les reesultats obtenus anterieurement. On a aussi observe plusieurs especes mineures, ce qui demontre le potentiel de cette methode pour etudier les voies reactionnelles de reactions interessantes d'un point de vue atmospherique, mais moins bien etudiees. Mots-cles: reacteur a pression atmospherique, ozone, tetramethylethylene (TME), spectrometre de masse a piege ionique, reaction en phase gazeuse. [Traduit par la Redaction], Introduction There are numerous approaches available to investigate the kinetics and mechanisms of gas-phase reactions; these include FTIR spectroscopy, (1-3) fast flow tube mass spectrometers (FF-MS), (4,5) turbulent flow tube [...]

Two active coronaviral proteins (3CLpro and Nsp15) have been studied using both the GCMS and docking methods. These coronaviral proteins have been examined with the methanol extract generated from leaves of the Arum palaestinum. According to the GC-MS findings, 19 major natural compounds are present in the plant's methanolic extract. The lowest Binding Energy (LBE) and the inhibition constant (Ki) have been used to identify and classify the potential of these lead drugs with their pharmacological properties. The affinity of these compounds with coronaviral proteins has been evaluated to reveal the usage of these compounds at the active sites of the receptors, 3CLpro (PDB ID: 6LU7) and Nsp15 (PDB ID: 6VWW). The results of β-Sitosterol, Androstan-3-one, Phenobarbital, Maltose, and α-Tocopherol show more affinity to Nsp15 and 3CLpro than to the supporting control drugs. Furthermore, an evaluation of the interactions of these components with the amino acids of 3CLpro and Nsp15 revealed that β-Sitosterol has the best LBE score and Ki value as compared with those of the approved medication and all other compounds under investigation. Consequently, these potential compounds may be modern inhibitors of coronavirus. Further in vitro and in vivo studies are needed for such computational findings. [ABSTRACT FROM AUTHOR]

Spectrofluorometric and spectrophotometric bivariate methods were developed for quantitative of Propranolol and Hydrochlorothiazide in drug tablets in an aqueous medium. The methods were tested according to ICH guidelines for linearity, recovery, and specificity and were found accurate, precise, sensitive, and free from interferences. The linearity was established over the ranges 0.025-0.30 and 0.010-0.20 mg/L in the first method, and 1.0-20.0 and 5.0-25.0 mg/L in the second method, for PRO and HCT, respectively. The excitation and emission wavelengths were 260, 345, and 270, 415 nm, for PRO and HCT in the first method, respectively. The recoveries were higher than 95% for both methods. Additionally, the results were statistically compared to that of standard chromatographic methods and showed that no significant difference among the methods regarding both accuracy and precision. Thus, the methods were successfully applied to the quantitation of PRO and HCT in combined formulations. The proposed methods are reliable, simple, sensitive, and adaptable and could effectively be an alternative method to HPLC. [ABSTRACT FROM AUTHOR]