Combinatorial Chemistry & High Throughput Screening - Volume 25, Issue 2, 2022

The precise and exquisite architecture of the retina is directly related to vision. Therefore, any mechanisms associated with disruption of retinal structure could affect the quality of vision. A large number of studies indicated that several cellular and molecular processes are involved in retina pathogenesis. Among different risk factors reported as important players in retina diseases, deregulation of epigenetic contributors has critical roles in the pathogenesis of these diseases. MicroRNAs (miRNAs) are a type of small non-coding RNAs that are involved in various signaling pathways involved in retina diseases. These molecules exert their function by targeting a sequence of cellular and molecular signals. Long-non coding RNAs (lncRNAs) and circular RNAs are other non-coding RNAs, which can exert their regulatory roles via miRNA sponging. In this regard, it has been showed that miRNA sponging could modulate a variety of pathways in retinal diseases. Besides miRNAs, exosomes are other players in the pathogenesis of retinal diseases. Exosomes are biological vectors that could carry their cargos to recipient cells. The cargos of exosomes (i.e., proteins, lncRNAs, miRNAs, and fragments of DNA) change behaviors of host cells. Here, we summarized the roles of miRNAs, miRNAs sponging and exosomes in the pathogenesis of retinal diseases.

Background: Atrial fibrillation (AF) is the most common persistent arrhythmia and an important factor leading to cardiovascular morbidity and mortality. Several key genes and diagnostic markers have been discovered with the development of advanced modern molecular biology techniques, but the etiology and pathogenesis of AF remained unknown. Methods: In this study, three-chip-seq data sets and an RNA-seq data set were integrated as a comprehensive network for pathway analysis of the biological functions of related genes in AF, hoping to provide a better understanding of the etiology and pathogenesis of AF. Results: Differential co-expression analysis identified 360 genes with specific expression in AF, and functional enrichment analysis further revealed that these genes were significantly correlated with focal expression (p <0.01), autophagy (p <0.01), and thyroid cancer. In addition, Af-specific proteinprotein interaction (PPI) networks were constructed based on AF-specific expression genes. Network topology analysis identified PLEKHA7, YWHAQ, PPP1CB, WDR1, AKT1, IGF1R, CANX, MAPK1, SRPK2 and SRSF10 genes as hub genes of the networks, and they were considered as potential biomarkers of AF because they were found to participate in the development of AF through Oocyte meiosis and focal expression. Finally, a diagnostic model for AF established with a support vector machine (SVM) demonstrated excellent predictive performance in internal and external data sets (AUC>0.9) and different platform data sets (mean AUC>0.75). Conclusion: Finally, a diagnostic model for AF was established, thus showing its potential in the early identification and prediction of AF.

Background: Hypertension is one of the most important health problems in the world and irbesartan and amlodipine are used in combination in various dosages for the treatment of high blood pressure. Objective: The aim of this study is to develop a fast, easy, sensitive, accurate, and precise squarewave voltammetry method for simultaneous determination of irbesartan and amlodipine besylate from pharmaceutical formulations at a hanging mercury drop electrode. Methods: In the applied method, since both active substances gave a peak at different potentials, no interference occurred between them. In optimization studies, Britton-Robinson buffer of pH 8.0 was chosen, in which the most appropriate peak shape and maximum peak current were observed. At the same time, as a result of instrumental parameter optimization to obtain reproducible results, 6 mV for scan increment, 30 mV for pulse amplitude, and 50 Hz for frequency were found suitable. Results: As a result of the calibration studies of the optimized method, linear working ranges were determined as 1.00-13.08 μg mL-1 for irbesartan and 5.83-16.51 μg mL-1 for amlodipine besylate. Limit of detection and limit of quantitation values were respectively calculated as 0.63 and 1.00 μg mL-1 for irbesartan and 0.50 and 1.98 μg mL-1 for amlodipine besylate. The results of precision values (RSD) ranged from 0.67% to 2.31% for irbesartan and 0.65% to 1.49% for amlodipine besylate. Accuracy values were calculated as -0.15% to 1.63% for irbesartan and -0.07% to 3.78% for amlodipine besylate. The results obtained from the recovery studies ranged from 101.05% to 102.78% and from 98.88% to 102.20% for amlodipine besylate and irbesartan, respectively. Conclusion: After the validation studies of the developed method were carried out, it was successfully applied to pharmaceutical formulations containing these active substances.

Background: The genus Thymus is one of the well-known members of the Lamiaceae, comprising about 215 species. It is a polymorphic genus in this family. Therefore, possible differences in chemical composition among polymorphs may result in differences in their biological activities. Objective: This study was designed to specify chemical composition in order to assess antioxidant activities and to characterize active constituents of essential oil of Thymus pubescens. Methods: Essential oil was collected by hydrodistillation and was analyzed using GC-MS and GCFID. Antioxidant activities were evaluated by ABTS radical cation scavenging and β-carotene bleaching inhibition methods. Detection and identification of antioxidant components were performed by TLC-bioautography assay using ABTS^•+ reagent. Results: GC analyses indicated the presence of 39 components, accounting for 96.64% of total constituents, with thymol (38.67%), γ-terpinene (7.46%), and p-cymene (5.54%) as the main components. The IC50 values for antioxidant activities were equal to 1.15 (1.05 – 1.25) μg/mL and 0.45 (0.33 – 0.62) μg/mL for ABTS^•+ scavenging and β-carotene bleaching inhibition tests, respectively. TLC-bioautography of oil resulted in the identification of thymol as the major antioxidant compound. Conclusion: Essential oil exhibited very potent and significant antioxidant activities correlated well with increasing dose in vitro.

Background: Due to the importance of fused chromene motifs in bioactive compounds, the current research aimed to explore novel methods for the construction of heterocyclic scaffolds. Regarding the attractive features of developing novel methodological approaches in the presence of heterogeneous nanocatalysts, we will try to synthesize 4-aryl-3,4-dihydro-2H,5H-pyrano[3,2- c]chromene-2,5-diones and 8-aryl-7,8-dihydro-6H-[1,3]dioxolo[4,5-g]chromene-6-ones. Objective: The aim of the present research was to prove the catalytic efficiency of the synthesized nickel(II) chromite nanoparticles (NiCr2O4 NPs) as bifunctional Lewis acid-Lewis base catalyst in the synthesis of pyrano[c]chromenediones and [1,3]dioxolo[g]chromeneones. Methods:Pyrano[c]chromenediones and [1,3]dioxolo[g]chromeneones were conveniently prepared from a three-component condensation reaction between aromatic aldehydes, Meldrum's acid, and active methylene compounds including 4-hydroxycoumarin or 3,4-methylenedioxyphenol using NiCr2O4 NPs as an efficient, readily available, and recyclable catalyst, under ethanol-drop grinding at room temperature. The synthesized compounds were characterized by IR, 1H, and 13C NMR spectroscopy and also by elemental analyses. Results: A number of 4-aryl-3,4-dihydro-2H,5H-pyrano[3,2-c]chromene-2,5-diones and 8-aryl- 7,8-dihydro-6H-[1,3]dioxolo[4,5-g]chromene-6-ones were effectively synthesized as target compounds in high yields. conclusion: This study provides a simple, inexpensive, and NiCr2O4 NPs catalyzed route to synthesis pyrano[c]chromenediones and [1,3]dioxolo[g]chromeneones in high yields. The reaction offers several benefits, including simple experimental procedures, higher yields, shorter reaction times, and the use of easily obtained and recyclable catalyst compared with previously reported methods and has a great scope for development.

Background: Dihydroquinazolinone derivatives are an important family of fused heterocyclic compounds which possess a wide range of biological, medicinal and pharmacological properties such as anti-tumor, anti-biotic, diuretic, analgesic, anti-hypertonic, anti-pyretic, antidepressant, anti-histamine and vasodilation activities. Introduction: So far, some acid catalysts, e.g. p-toluenesulfonic acid, silica sulfuric acid, zinc(II) perfluorooctanoate, gallium(III) triflate, ionic liquid, Al(H2PO4)3, I2, montmorillonite K-10, Amberlyst-15, Al/Al2O3 and Fe3O4 nanoparticles, have been reported to accomplish this threecomponent reaction. Some of these methods have drawbacks such as toxic solvents and catalysts, long reaction time, the use of expensive catalysts and adverse yields. Methods: A mixture of benzaldehydes (1mmol), isatoic anhydride (1 mmol), Glycine (1 mmol) and OImDSA (2 mL) were stirred at room temperature for the required reaction times (1-2 h). The progress of the reaction was monitored by TLC (EtOAc: petroleum ether 1:2). After completion of the reaction, as indicated by TLC, the ionic liquid was separated by extraction with 2×15 mL of water. The solid residue was separated by recrystallization from EtOH. The pure products were collected in 86-97% yields. Results: Herein, we report the mild synthesis of some derivatives of 2-aryl-quinazolin-4(1H)-ones from isatoic anhydride and Glycine using OImDSA, which has been found to be an efficient synthesis method, with depleted side effects, reduced reaction steps, increased efficiency and curtailed reaction time, in continuation of our research on the synthesis of heterocyclic and pharmaceutical compounds. Conclusion: In conclusion, we have developed a simple, green and efficient protocol for the synthesis of 2-aryl-quinazolin-4(1H)-ones using OImDSA. Simplicity, easy practice, inexpensive, environmentally friendly and reusable ionic liquid are notable attributes of this new method. To the best of our knowledge, this is the first report on the synthesis of a new library of quinazolin-4(1H)- ones derived from Glycine as a natural substrate based on green chemistry conditions.

Objective: The research work aims to synthesize novel series of hydrazones and antioxidant screening. It also aims to evaluate the binding affinities and in silico methods for identifying possible drug targets of synthesized compounds. Methods: This report briefly explains the synthesis of a novel series of hydrazones. It was synthesized via. hydrazinolysis of esters to obtain hydrazide, treated with aldehyde and acetophenone to get hydrazones. The spectral confirmed hydrazones exhibited excellent to comparable anti-oxidant as compared to the standard drugs Butylated hydroxytoluene (BHT) and Ascorbic acid. Molecular docking on myeloperoxidase (MPO) demonstrated the ability of this scaffold to correctly recognize the target and engage in significant bonded and non-bonded interactions with key residues therein. Results and Discussion: In this study, we report effectively synthesized compounds BK-35, BK- 41, BK-26, BK-28, and BK-39 that showed the best DPPH radical scavenging activity. The docking results clearly showed the binding mode of hydrazones into the active site of Myeloperoxidase (MPO). In in-silico results, none of the synthesized compounds, BK-24 to BK- 41, violated Lipinski’s rule of five (miLog P ≤ 5). Conclusions: In vitro preliminary anti-oxidant screening results in support by in Silico binding affinity data of novel hydrazones of levofloxacin related molecules BK-24 to BK-41 reported here have emerged as excellent anti-oxidant agents. The inference derived from the in vitro anti-oxidant screening data and the quantitative insights derived from the per-residue interaction analysis with MPO enzyme are now being fruitfully utilized for site-specific mutation around the nucleus to identify selective and potent anti-oxidants.

Aim and Objectives:This research work deals with the highly selective oxidation of benzyl alcohol to benzaldehyde by palladium doped graphene oxide catalyst, which was synthesized by a modified Hummer’s method. The effect of reaction parameters like temperature, time and catalyst loading were studied. It was found that fine-tuning of reaction temperature and presence of a small amount of benzyl alcohol in a product prevented the undesirable formation of benzoic acid crystals, which form on auto-oxidation of benzaldehyde. Benzoic acid or substituted benzoic acid formation was hindered by the presence of < 2% benzyl alcohol at a reaction temperature of 50˚C, which was further supported by palladium doped graphene oxide catalyst. Materials and Methods: Modified Hummer’s method was used for the synthesis of graphene oxide and palladium doped graphene oxide was synthesized by in-situ method in which graphene oxide dispersed in 20mL of distilled water was ultrasonicated for 2h. Palladium solution was added and it was further ultrasonicated for 30min for homogeneous deposition of palladium on a graphene oxide support. To this, 2 mL of sodium borohydride solution was added and stirred at room temperature for 4h. The resulting solution was centrifuged, and the residue was dried at 60°C for 12 h. Results: The morphological characteristics and the functional groups of supported catalysts were characterized by X-ray diffraction, Field emission scanning spectroscopy, and Fourier transform infrared spectroscopy. The produced benzaldehyde was characterized by gas chromatography. Conclusion: PdGO catalyst was prepared using sodium borohydride as a reducing agent by modified Hummer’s method and utilized for the oxidation of benzyl alcohol to benzaldehyde. A maximum conversion of 89% and selectivity of 99% were obtained and the catalyst could be reused up to five times without any compromise on conversion and selectivity.

Background: Malaria is caused by different species of Plasmodium; among which P. falciparum is the most severe. Coptis teeta is an ethnomedicinal plant of enormous importance for tribes of northeast India. Objective: In this study, the antimalarial activity of the methanol extracts of Coptis teeta was evaluated in vitro and lead identification was carried out via in silico study. Methods: On the basis of the in vitro results, in silico analysis by application of different modules of Discovery Studio 2018 was performed on multiple targets of P. falciparum taking into consideration some of the compounds reported from C. teeta. Results: The IC50 of the methanol extract of Coptis teeta was reported to be 0.08 μg/ml in 3D7 strain and 0.7 μg/ml in Dd2 strain of P. falciparum. From the docking study, noroxyhydrastatine was observed to have better binding affinity in comparison to chloroquine. The binding of noroxyhydrastinine with dihydroorotate dehydrogenase was further validated by molecular dynamics simulation and was observed to be significantly stable in comparison to the co-crystal inhibitor. During simulations, it was observed that noroxyhydrastinine retained the interactions, giving strong indications of its effectiveness against the P. falciparum proteins and stability in the binding pocket. From the Density-functional theory analysis, the bandgap energy of noroxyhydrastinine was found to be 0.186 Ha, indicating a favorable interaction. Conclusion: The in silico analysis as an addition to the in vitro results provides strong evidence of noroxyhydrastinine as an antimalarial agent.

Background: Solubility/dissolution is said to be the key factor that influences the oral bioavailability of drug and is also the rate limiting step in formulation development. Objective: Hydrochlorothiazide (HCZ) is a BCS Class IV drug with low solubility and low permeability. The present work aimed to increase the solubility of hydrochlorothiazide using blends of natural and synthetic hydrotropes. Methods: Two hydrotropes one from natural (piperazine) and other from the synthetic origin (sodium benzoate) were selected for the formulation of solid dispersion (SD) of HCZ. Preliminary trial batches were prepared by considering the safe dose of both the selected hydrotropes i.e. sodium benzoate (SB) and piperazine (PP). A 3² full factorial design was opted for preparing the optimized solid dispersion of hydrochlorothiazide. Results: The quadratic models were found to be best fitted for the studied responses, which were percent solubility and in-vitro drug release. The results showed increased solubility and in-vitro drug release of HCZ solid dispersions as a function of increasing levels of both hydrotropes. Conclusion: In this work, it was concluded that the use of natural hydrotropes along with synthetic hydrotropes gave an effective and safe approach for the solubility enhancement of the HCZ.

Background: Bacterial infection is a frequent complication in cancer and immunocompromised patients. The emergence of antibiotic resistance is a significant health problem and cancer patients are at risk of repeated infections with drug-resistant bacteria. Objective: This investigation aimed to identify predictors of repeat infections of Escherichia coli and Klebsiella pneumoniae and drug resistance in cancer patients admitted to the intensive care unit (ICU) in Upper Egypt. Methods: Blood, urine, sputum, pus, and mouth and nose swabs were collected from patients at the Pediatric Oncology and Medical Oncology ICUs during the period from February 2017 to May 2018. The samples were assessed by antibiotic susceptibility test and further evaluated by genetic testing for the temoniera (TEM) gene of β-lactamase. Samples positive for K. pneumoniae and E. coli were included and isolates positive for other microorganisms were excluded. Results: The study included 107 patients with malignant neoplasms and 136 samples. Repeated infection with K. pneumoniae and E. coli occurred in 31% and 22.45% of patients, respectively. Patients who stayed for a longer period in the ICU were more likely to have repeated infections (OR 1.25, 95%CI 1.10-1.44, p=0.001) after control of other confounding factors. The type of malignant neoplasm, whether it was a hematologic or solid tumor (OR 7.46, 95% CI 2.56-21.7, p=0.0002) and a longer prior stay in the ICU (OR 1.14, 95% CI 1.02-1.28, p=0.025) remained the independent predictors for the drug resistance in the last infection. The TEM type of β-lactamase was encoded in 48.68% and 66.67% of K. pneumoniae and E. coli, respectively. Conclusion: Reinfection with K. pneumoniae and E. coli in patients with cancer can occur as the number of days in the hospital increases. Total prior days spent in the ICU by cancer patients were independently associated with both repeated infections and drug resistance. Samples from patients with hematologic neoplasms were associated with drug resistance.

Background: Hepatitis C Virus (HCV) is one of the serious health issues affecting onethird of the world’s population. The high variations of the HCV genome are ascribed to quick replication by NS5B polymerase and are thus the most attractive target for developing anti-HCV agents. Objective: The current study aimed to discover novel phytochemicals that harbor the potential of NS5B polymerase inhibition. Methods: In this computational study, a molecular docking approach was used to screen phytochemicals with the best binding and spatial affinity with NS5B at the Palm I region. The topranked compounds were then subjected to an in-silico pharmacokinetic and toxicological study. Results: The virtual screening provided seven ‘hit compounds’ including Betanin, 3,5'- dihydroxythalifaboramine, Diarctigenin, 6'-desmethylthalifaboramine, Cephalotaxine, 5alpha-O- (3'-dimethylamino-3'-phenylpropionyl) taxinine M and IsoTetrandrine with minimum binding score compared to the reference drug, sofosbuvir (−14.7 kcal/mol). The absorption, distribution, metabolism, excretion, and toxicity (ADMET) and thorough toxicological analysis revealed a favorable safety profile of these compounds. Conclusion: The study demonstrates the identified phytochemicals. These may serve as potential antiviral compounds that can provide an alternative approach for amelioration of HCV.