roshanak hariri

In this study entacapone, levodopa, and carbidopa, were determined with high precision in the presence of each other. UV-VIS spectroscopy was used as an easy and low-cost technique for the analysis and the derivative spectrophotometric method was applied for elimination of absorption interferences. For this purpose, the derivative spectra of each compound were studied separately, and zero crossing points were determined for each of them. The zero-crossing points in which the absorption was observed only for one compound were found and evaluated for quantitative analysis. Calibration curves were drawn from the second and third derivative signals for each compound and the linear range was determined. The method was linear in the range of 1-5 µg/mL for levodopa, 0.25-1.7 µg/mL for carbidopa, and 2-14 µg/mL for entacapone. The accuracy and precision of the proposed method were evaluated by within-day and between-day tests (CV < 1.56% and error < 1.7%) and finally, these drugs were determined in pharmaceutical dosage forms by the developed method.

The present study produces a new, accurate, and simple spectrofluorimetric technique for the determination of pregabalin after derivatization with 9-fluorenylmethyl chloroformate in mild basic medium. Pregabalin, containing a primary amine group, reacts with 9-fluorenylmethyl chloroformate, a fluorophore reagent, in borate buffer and produces a fluorescent derivative. The maximum fluorescence intensity of the derivative and reagent was obtained at 315 nm after excitation at 280 nm. The fluorescence intensity of the reagent increases after derivatization with pregabalin, and the difference in the fluorescence intensity is proportional to the concentration of pregabalin. Experimental parameters which affect the derivatization reaction were studied. The best derivatization reaction between pregabalin and 9-fluorenylmethyl chloroformate was obtained after 30 sec. when 40 µg mL-1 of the reagent was used in a borate buffer of pH 9.0. Under optimized conditions, the linearity range (6-150 µg mL-1) of the method with a correlation coefficient of r2 0.9998, accuracy (Error<1.7%), and precision (CV<2.0%) was acceptable. The validated method was utilized for quantifying pregabalin in dosage form without interferences and showed good agreement with a reference method. 

The spread of cancer, coupled with the challenges posed by complex treatments, stands as one of the foremost medical issues in today's world. Researchers consistently strive to identify novel compounds with enhanced efficacy and reduced side effects. Aromatase, a pivotal enzyme in estrogen receptor-positive breast cancer, plays a significant role. Estrogens, crucial for human physiology, particularly in women, contribute to sexual development and reproduction. The adverse effects associated with specific aromatase inhibitors underscore the imperative to discover new inhibitors characterized by higher selectivity, lower toxicity, and improved potency.

This research is a basic study in which the semi-prepared aromatase kit was used to investigate synthetic compounds, specifically triazolyl chromanone oxime ethers. The most promising compounds were selected and subjected to molecular docking studies based on the inhibition results obtained.

Out of the 40 compounds examined, seven samples exhibiting the most pronounced inhibitory effects were chosen for further scrutiny and IC50 determination. Notably, derivatives 6b and 20b demonstrated the most robust inhibitory effects, with IC50 values of 0.37 and 0.69 μM, respectively. Examining the interactions between these compounds and the aromatase enzyme revealed a significant relationship with the enzyme's active site.

In conclusion, the evaluation of various derivatives containing the triazolyl chromanone oxime ether structure suggests their considerable potential as aromatase enzyme inhibitors. Further exploration involving the design of structures within this category holds the promise of yielding more effective derivatives for inhibiting this enzyme.

Alzheimer’s disease (AD), the main form of dementia, is a multifactorial neurodegenerative disease, and several hypotheses have been proposed for its pathogenesis. Among them, cholinergic hypofunction is the main reason and plays a significant role in cognitive impairment. According to this theory, ChE inhibitors improve the performance of the cholinergic system and increase memory function. Thus, this study investigated a novel series of 2-amino-pyrano[3,2-c]quinoline-3-carbonitrile derivatives bearing benzyloxy phenyl moiety as ChE enzyme inhibitors.

The synthesized compounds 6a-o are divided into three series based on benzyloxy phenyl moiety. The structure of all compounds was identified by the NMR (1H and 13C) and IR spectra. Then, their inhibitory activities against ChE enzymes were evaluated by Ellman’s spectrophotometrical method. The kinetic and molecular docking studies were performed for compound 6l as the most potent butyrylcholinesterase (BChE) inhibitor.

The 2-amino-4-(4-((4-fluorobenzyl)oxy)-3-methoxyphenyl)-5-oxo-5,6-dihydro-4H-pyrano[3,2-c] quinoline-3-carbonitrile (6l) demonstrated the best anti-BChE activity with a half maximal inhibitory concentration value of 1.00 ± 0.07. The kinetic and molecular docking studies confirmed that 6l is a mixed inhibitor and binds to both the anionic catalytic site and peripheral anionic site (PAS) of BChE. In silico study approved that the methoxy group on the middle phenyl ring has a significant role in interacting with the PAS of the enzyme.

These findings indicated that 2-amino-pyrano[3,2-c]quinoline-3-carbonitrile derivatives bearing benzyloxy phenyl moiety have therapeutic potential as BChE inhibitors in the last stages of AD.

Mometasone furoate is a synthetic glucocorticoid with anti-inflammatory and anti-allergic effects, used for the treatment of allergic rhinitis, asthma, and dermatoses. In this study, a spectrophotometric method, as a selective and sensitive method, was developed for the determination of mometasone furoate after derivatization. For this purpose, mometasone was first reacted with sodium cyanide to prepare the drug derivatives. After that, the effects of different variables such as reaction solvent, concentration of the reagents, pH, and reaction time were studied. The final results showed that the determination method was linear in the range of 2-18 μg/ml. It seems that after 24 hours, the reaction was complete. The reaction product was characterized by NMR and FT-IR spectroscopy, and the accuracy and precision of the developed method were also studied. At last, the method was checked on Mometasone Ointment (0.1%), and the results were compared with the results of the HPLC method as a standard method.