Pharmacophore-based, rationale design, and efficient synthesis of novel tetrahydrobenzo[b]thiophene candidates as potential dual Topo I/II inhibitors and DNA intercalators.

A series of tetrahydrobenzo[b]thiophene derivatives was designed and synthesized as dual topoisomerase (Topo) I/II inhibitors implicating potential DNA intercalation. Ethyl-2-amino-3-cyano-4,5,6,7-tetrahydrobenzo[b]thiophene-4-carboxylate (1) was prepared by modification of the Gewald reaction procedure using a Fe2O3 nanocatalyst and then it was used as a building block for the synthesis of tetrahydrobenzo[b]thiophene candidates (2-14). Interestingly, compound 14 showed the best cytotoxic potential against hepatocellular, colorectal, and breast cancer cell lines (IC50 = 7.79, 8.10, and 3.53 µM), respectively, surpassing doxorubicin at breast cancer (IC50 = 4.17 µM). Meanwhile, the Topo I and II inhibition assay displayed that compound 3 could exhibit the best inhibitory potential among the investigated candidates (IC50 = 25.26 and 10.01 nM), respectively, in comparison to camptothecin (IC50 = 28.34 nM) and doxorubicin (IC50 = 11.01 nM), as reference standards. In addition, the DNA intercalation assay showed that compound 14 could display the best binding affinity with an IC50 value of 77.82 µM in comparison to doxorubicin (IC50 = 58.03 µM). Furthermore, cell cycle and apoptosis analyses described that compound 3 prompts the G1 phase arrest in michigan cancer foundation-7 cancer cells and increases the apoptosis ratio by 29.31% with respect to untreated cells (2.25%). Additionally, the conducted molecular docking assured the promising binding of the investigated members toward Topo I and II with potential DNA intercalation. Accordingly, the synthesized compounds could be treated as promising anticancer candidates for future optimization.

Biological evaluation, docking studies, and in silico ADME prediction of some pyrimidine and pyridine derivatives as potential EGFRWT and EGFRT790M inhibitors.

Herein, a set of pyridine and pyrimidine derivatives were assessed for their impact on the cell cycle and apoptosis. Human breast cancer (MCF7), hepatocellular carcinoma (HEPG2), larynx cancer (HEP2), lung cancer (H460), colon cancers (HCT116 and Caco2), and hypopharyngeal cancer (FADU), and normal Vero cell lines were used. Compounds 8 and 14 displayed outstanding effects on the investigated cell lines and were further tested for their antioxidant activity in MCF7, H460, FADU, HEP2, HEPG2, HCT116, Caco2, and Vero cells by measuring superoxide dismutase (SOD), malondialdehyde content (MDA), reduced glutathione (GSH), and nitric oxide (NO) content. Besides, Annexin V-FITC apoptosis detection and cell cycle DNA index using the HEPG-2 cell line were established on both compounds as well. Furthermore, compounds 8 and 14 were assessed for their EGFR kinase (Wild and T790M) inhibitory activities, revealing eligible potential. Additionally, molecular docking, ADME, and SAR studies were carried out for the investigated candidates.

Investigating the potential anticancer activities of antibiotics as topoisomerase II inhibitors and DNA intercalators: in vitro, molecular docking, molecular dynamics, and SAR studies.

Topoisomerase II (TOP-2) is a promising molecular target for cancer therapy. Numerous antibiotics could interact with biologically relevant macromolecules and provoke antitumor potential. Herein, molecular docking studies were used to investigate the binding interactions of 138 antibiotics against the human topoisomerase II-DNA complex. Followed by the MD simulations for 200 ns and MM-GBSA calculations. On the other hand, the antitumor activities of the most promising candidates were investigated against three cancer cell lines using doxorubicin (DOX) as a reference drug. Notably, spiramycin (SP) and clarithromycin (CL) showed promising anticancer potentials on the MCF-7 cell line. Moreover, azithromycin (AZ) and CL exhibited good anticancer potentials against the HCT-116 cell line. Finally, the TOP-2 enzyme inhibition assay was carried out to confirm the proposed rationale. Briefly, potent TOP-2 inhibitory potentials were recorded for erythromycin (ER) and roxithromycin (RO). Additionally, a SAR study opened eyes to promising anticancer pharmacophores encountered by these antibiotics.HighlightsMolecular docking studies of 139 antibiotics against the topoisomerase II-DNA complex.SP, RO, AZ, CL, and ER were the most promising and commercially available candidates.Molecular dynamics simulations for 200 ns for the most promising five complexes.MM-GBSA calculations for the frontier five complexes.SP and CL showed promising anticancer potentials on the MCF-7 cell line, besides, AZ and CL exhibited good anticancer potentials against the HCT-116 cell line.Potent TOP-2 inhibitory potentials were recorded for ER and RO.

Structure based design and synthesis of 3-(7-nitro-3-oxo-3,4-dihydroquinoxalin-2-yl)propanehydrazide derivatives as novel bacterial DNA-gyrase inhibitors: In-vitro, In-vivo, In-silico and SAR studies.

Antimicrobial resistance (AMR) is one of the critical challenges that have been encountered over the past years. On the other hand, bacterial DNA gyrase is regarded as one of the most outstanding biological targets that quinolones can extensively inhibit, improving AMR. Hence, a novel series of 3-(7-nitro-3-oxo-3,4-dihydroquinoxalin-2-yl)propanehydrazide derivatives (3-6j) were designed and synthesized employing the quinoxaline-2-one scaffold and relying on the pharmacophoric features experienced by the quinolone antibiotic; ciprofloxacin. The antibacterial activity of the synthesized compounds was assessed via in-vitro approaches using eight different Gram-positive and Gram-negative bacterial species. Most of the synthesized compounds revealed eligible antibacterial activities. In particular, compounds 6d and 6e displayed promising antibacterial activity among the investigated compounds. For example, compounds 6d and 6e displayed MIC values of 9.40 and 9.00 µM, respectively, regarding S. aureus, and 4.70 and 4.50 µM, respectively, regarding S. pneumonia in comparison to ciprofloxacin (12.07 µM). The cytotoxicity of compounds 6d and 6e were performed on normal human WI-38 cell lines with IC50 values of 288.69 and 227.64 µM, respectively assuring their safety and selectivity. Besides, DNA gyrase inhibition assay of compounds 6d and 6e was carried out in comparison to ciprofloxacin, and interestingly, compounds 6d and 6e disclosed promising IC50 values of 0.242 and 0.177 µM, respectively, whereas ciprofloxacin displayed an IC50 value of 0.768 µM, assuring the proposed mechanism of action for the afforded compounds. Consequently, compounds 6d and 6e were further assessed via in-vivo approaches by evaluating blood counts, liver and kidney functions, and histopathological examination. Both compounds were found to be safer on the liver and kidney than the reference ciprofloxacin. Moreover, in-silico molecular docking studies were established and revealed reasonable binding affinities for all afforded compounds, particularly compound 6d which exhibited a binding score of -7.51 kcal/mol, surpassing the reference ciprofloxacin (-7.29 kcal/mol) with better anticipated stability at the DNA gyrase binding pocket. Moreover, ADME studies were conducted, disclosing an eligible bioavailability score of >0.55 for all afforded compounds, and reasonable GIT absorption without passing the blood brain barrier was attained for most investigated compounds, ensuring their efficacy and safety. Lastly, a structure activity relationship study for the synthesized compounds was established and unveiled that not only the main pharmacophores required for DNA gyrase inhibition are enough for exerting promising antimicrobial activities, but also derivatization with diverse aryl/hetero aryl aldehydes is essential for their enhanced antimicrobial potential.

Design and synthesis of novel benzoazoninone derivatives as potential CBSIs and apoptotic inducers: In Vitro, in Vivo, molecular docking, molecular dynamics, and SAR studies.

Apparently, tubulin inhibitors binding to the colchicine-binding site (CBS) currently have outstanding attention for cancer treatment. So, a series of benzo[b]azonin-2-one derivatives having the same pharmacophoric features as colchicine binding site inhibitors (CBSIs) were synthesized targeting the CBS of ß-tubulin. The antiproliferative activities of the newly synthesized compounds were assessed against five different cancer cell lines; HepG-2, MCF-7, MDA-MB-231, HCT-116, and Caco-2. Compounds 7a and 7d displayed promising inhibitory activities against all tested cell lines. They were further estimated towards ß-tubulin at CBS along with colchicine (Col) as a reference drug. It was shown that the assessed candidates (7a and 7d) and Col exhibited CBSI activities of 5492, 3771, and 486c.p.m./mg protein, respectively, at a concentration of 10 µM. Furthermore, compound 7d was picked out to assess its effects on apoptosis and cell-cycle profile using Annexin V-FITC and PI staining assay. In addition, the apoptotic activity of 7d was investigated using gene expression analysis of apoptosis-related genes of P53, Bax, Caspases 3 and 9, and Bcl-2 in both treated and untreated cells. Moreover, compound 7d was further assessed through in vivo studies using solid Ehrlich carcinoma (SEC)-bearing mice. Furthermore, both molecular docking and molecular dynamics simulations (for 150 ns) were performed to investigate their mechanism of action as potential CBSIs and give more insights into the behavior of the examined candidates within the ß-tubulin subunit of the CBS. On the other hand, in silico ADMET studies were carried out to assess the pharmacokinetic features, drug/lead likeness, and toxicity parameters of the newly synthesized derivatives. Finally, to anticipate the possible changes in the antimitotic activities upon future structural modifications of the investigated compounds, a structure-activity relationship study (SAR) was accomplished.

Ligand-based design, synthesis, computational insights, and in vitro studies of novel N-(5-Nitrothiazol-2-yl)-carboxamido derivatives as potent inhibitors of SARS-CoV-2 main protease.

The global outbreak of the COVID-19 pandemic provokes scientists to make a prompt development of new effective therapeutic interventions for the battle against SARS-CoV-2. A new series of N-(5-nitrothiazol-2-yl)-carboxamido derivatives were designed and synthesised based on the structural optimisation principle of the SARS-CoV Mpro co-crystallized WR1 inhibitor. Notably, compound 3b achieved the most promising anti-SARS-CoV-2 activity with an IC50 value of 174.7 µg/mL. On the other hand, compounds 3a, 3b, and 3c showed very promising SARS-CoV-2 Mpro inhibitory effects with IC50 values of 4.67, 5.12, and 11.90 µg/mL, respectively. Compound 3b docking score was very promising (-6.94 kcal/mol) and its binding mode was nearly similar to that of WR1. Besides, the molecular dynamics (MD) simulations of compound 3b showed its great stability inside the binding pocket until around 40 ns. Finally, a very promising SAR was concluded to help to design more powerful SARS-CoV-2 Mpro inhibitors shortly.

Ligand-based design and synthesis of N'-Benzylidene-3,4-dimethoxybenzohydrazide derivatives as potential antimicrobial agents; evaluation by in vitro, in vivo, and in silico approaches with SAR studies.

Herein, a series of N'-benzylidene-3,4-dimethoxybenzohydrazide derivatives were designed and synthesised to target the multidrug efflux pump (MATE). The antibacterial activities were screened against S. aureus, Acinetobacter, S. typhi, E. coli, and P. aeruginosa, whereas their antifungal activities were screened against C. albicans. Compounds 4a, 4h, and 4i showed the most promising antibacterial and antifungal activities. Moreover, compounds 4h and 4i being the broader and superior members regarding their antimicrobial effects were selected to be further evaluated via in vivo testing using biochemical analysis and liver/kidney histological examination. Additionally, molecular docking was carried out to attain further deep insights into the synthesised compounds' binding modes. Also, ADMET studies were performed to investigate the physicochemical/pharmacokinetics features and toxicity parameters of the synthesised derivatives. Finally, a structure-antimicrobial activity relationship study was established to facilitate further structural modifications in the future. HighlightsA series of new N'-benzylidene-3,4-dimethoxybenzohydrazide derivatives were designed and synthesised targeting the multidrug efflux pump (MATE) guided by the pharmacophoric features of the co-crystallized native inhibitor of the target protein.The newly synthesised compounds were assessed through in vitro, in vivo, and in silico approaches.Using the agar well diffusion assay, the antibacterial activities of the synthesised compounds were screened against S. aureus, Acinetobacter, S. typhi, E. coli, and P. aeruginosa, whereas, their antifungal activities were screened against C. albicans.The minimal inhibitory concentration (MIC) and the minimal bactericidal concentration (MBC) of the synthesised compounds were investigated on variable microbial species.Compounds (4h and 4i) -as the broader and superior members regarding their antimicrobial effects- were further evaluated via in vivo testing using bio-chemical analysis and liver/kidney histological examination.A molecular docking study and ADMET in silico studies were performed.A structure-antimicrobial activity relationship study was established to facilitate further structural modifications in the future.

Determination of six drugs used for treatment of common cold by micellar liquid chromatography.

The use of organic solvents as eluants in RP-HPLC has an important role to decrease retention time and improve peak shape; however, it has high environmental impacts. Their production and disposal represent economic and biohazard problems. So, alternatives had to be introduced and studied to minimize such pollution. Combination of sodium dodecyl sulfate (SDS) together with polyoxyethylene-23-lauryl ether (Brij-35) was studied as an alternative to the presence of organic solvents on the separation performance of six active pharmaceutical ingredients. Response surface methodology was applied to test the impact of three independent variables; concentrations of SDS and Brij-35, as well as, pH of the mobile phase; on retention, peak symmetry, and resolution of the analytes using a rotatable central composite design. Significant variables were determined and the suggested models for predicting retention and resolution parameters were significant. Meanwhile, the common cold is the most abundant disease treated with over-the-counter (OTC) medications worldwide. In 2015, the USA recorded $9.56 billion total sales of OTC cold and cough medicaments alone, with average individual patient expenditure of $338. The worldwide sales and generics of common cold and cough products keep growing annually. The six active pharmaceutical molecules under study, namely, paracetamol, guaifenesin, pseudoephedrine, ibuprofen, chlorpheniramine, and dextromethorphan, are widely used in common cold products. The predicted optimum conditions were validated using mobile phase consisting of 93.6 mM SDS, 32.0 mM Brij-35, and 10.0 mM sodium dihydrogen phosphate, adjusted at pH 5.2, column temperature 35° C, and detection at 215-nm wavelength. The method was successfully applied to determine 12 different combination formulae of the analytes in their pharmaceutical products and was assessed for greenness on two novel metrics. A thorough comparison to previously reported methods was included and methods were assessed against greenness metrics Green Analytical Procedure Index and Analytical Greenness Metric to demonstrate superiority.

Harnessing molecular hybridization approach to discover novel quinoline EGFR-TK inhibitors for cancer treatment.

Aim: Using molecular hybridization approach, novel 18 quinoline derivatives (6a-11) were designed and synthesized as EGFR-TK inhibitors. Materials & methods: The antiproliferative activity was assessed against breast (MCF-7), leukemia (HL-60) and lung (A549) cancer cell lines. Moreover, the most active quinoline derivatives (6d and 8b) were further investigated for their potential as EGFR-TK inhibitors. In addition, cell cycle analysis and apoptosis induction activity were conducted. Results: A considerable cytotoxic activity was attained with IC50 values spanning from 0.06 to 1.12 µM. Besides, the quinoline derivatives 6d and 8b displayed potent inhibitory activity against EFGR with IC50 values of 0.18 and 0.08 µM, respectively. Conclusion: Accordingly, the afforded quinoline derivatives can be used as promising lead anticancer candidates for future optimization.

[Box: see text].

Design and Synthesis of 2-(4-Bromophenyl)Quinoline-4-Carbohydrazide Derivatives via Molecular Hybridization as Novel Microbial DNA-Gyrase Inhibitors.

Microbial DNA gyrase is regarded as an outstanding microbial target. Hence, 15 new quinoline derivatives (5-14) were designed and synthesized. The antimicrobial activity of the afforded compounds was pursued via in vitro approaches. The investigated compounds displayed eligible MIC values, particularly against G-positive Staphylococcus aureus species. Consequently, an S. aureus DNA gyrase supercoiling assay was performed, using ciprofloxacin as a reference control. Obviously, compounds 6b and 10 unveiled IC50 values of 33.64 and 8.45 µM, respectively. Alongside, ciprofloxacin exhibited an IC50 value of 3.80 µM. Furthermore, a significant docking binding score was encountered by compound 6b (-7.73 kcal/mol), surpassing ciprofloxacin (-7.29 kcal/mol). Additionally, both compounds 6b and 10 revealed high GIT absorption without passing the blood brain barrier. Finally, the conducted structure-activity relationship study assured the usefulness of the hydrazine moiety as a molecular hybrid for activity either in cyclic or opened form.

Ligand-Based Design on the Dog-Bone-Shaped BIBR1532 Pharmacophoric Features and Synthesis of Novel Analogues as Promising Telomerase Inhibitors with In Vitro and In Vivo Evaluations.

Telomerase is an outstanding biological target for cancer treatment. BIBR1532 is a non-nucleoside selective telomerase inhibitor; however, it experiences ineligible pharmacokinetics. Herein, we aimed to design new BIBR1532-based analogues as promising telomerase inhibitors. Therefore, two novel series of pyridazine-linked to cyclopenta[b]thiophene (8a-f) and tetrahydro-1-benzothiophene (9a-f) were synthesized. A quantitative real-time polymerase chain reaction was utilized to investigate the telomerase inhibitory activity of candidates. Notably, 8e and 9e exhibited the best inhibition profiles. Moreover, 8e showed strong antitumor effects against both MCF-7 and A549 cancer cell lines. The effects of 8e on the cell cycle and apoptosis were measured. Besides, 8e was evaluated for its in vivo antitumor activity using solid Ehrlich carcinoma. The reduction in both the tumor weight and volume was greater than doxorubicin. Also, molecular docking and ADME studies were performed. Finally, a SAR study was conducted to gain further insights into the different telomerase inhibition potentials upon variable structural modifications.

Tamarindus indica Extract as a Promising Antimicrobial and Antivirulence Therapy.

The worldwide crises from multi-drug-resistant (MDR) bacterial infections are pushing us to search for new alternative therapies. The renewed interest in medicinal plants has gained the attention of our research group. Tamarindus indica L. (T. indica) is one of the traditional medicines used for a wide range of diseases. Therefore, we evaluated the antimicrobial activities of ethanolic extract of T. indica. The inhibitions zones, minimum inhibitory concentration (MIC), minimum bactericidal concentration (MBC), and fractional inhibitor concentration indices (FICI) against Gram+ve and -ve pathogens were detected. The bioactive compounds from T. indica extract were identified by mass spectroscopy, thin-layer chromatography, and bio-autographic assay. We performed scanning electron microscopy (SEM) and molecular docking studies to confirm possible mechanisms of actions and antivirulence activities, respectively. We found more promising antimicrobial activities against MDR pathogens with MIC and MBC values for Staphylococcus aureus (S. aureus) and Pseudomonas aeruginosa (P. aeruginosa), i.e., (0.78, 3.12 mg/mL) and (1.56, 3.12 mg/mL), respectively. The antimicrobial activities of this extract were attributed to its capability to impair cell membrane permeability, inducing bacterial cell lysis, which was confirmed by the morphological changes observed under SEM. The synergistic interactions between this extract and commonly used antibiotics were confirmed (FICI values < 0.5). The bioactive compounds of this extract were bis (2-ethylhexyl)phthalate, phenol, 2,4-bis(1,1-dimethylethyl), 1,2-benzenedicarboxylic acid, and bis(8-methylnonyl) ester. Additionally, this extract showed antivirulence activities, especially against the S. aureus protease and P. aeruginosa elastase. In conclusion, we hope that pharmaceutical companies can utilize our findings to produce a new formulation of T. indica ethanolic extract with other antibiotics.

Design and synthesis of novel pyrazolopyrimidine candidates as promising EGFR-T790M inhibitors and apoptosis inducers.

Aim: Our objective was to design and synthesize a new range of pyrazolopyrimidines while maintaining the key pharmacophoric features of EGFR tyrosine kinase inhibitors. Materials & methods: Percentage inhibition in 14 human cancer cell lines and IC50 values were recorded. Compounds 6c, 7e and 7f were examined against both wild and mutant (T790M) EGFR subtypes. Apoptosis markers, cell cycle arrest, apoptosis assay and molecular docking were performed. Results: Compounds 6c, 7e and 7f demonstrated superior inhibitory potentials against wild and mutant (T790M) EGFR subtypes. A molecular docking study showed that compounds 6c and 7e had the best fit. Conclusion: The designed candidates demonstrated superior inhibitory potential as promising EGFR-T790M inhibitors that agrees with the proposed rationale.

Investigating the promising SARS-CoV-2 main protease inhibitory activity of secoiridoids isolated from Jasminum humile; in silico and in Vitro assessments with structure-activity relationship.

The proteolytic enzyme 3 C-like protease (3Clpro or Mpro) is considered the most important target for SARS-CoV-2 which could be attributed to its crucial role in viral maturation and/or replication. Besides, natural phytoconstituents from plant origin are always promising lead compounds in the drug discovery area. Herein, the previously isolated and identified seven compounds from Jasminum humile (J. humile) were examined in vitro and in silico against the SARS-CoV-2 Mpro. First, the Vero E6 cells were utilized to pursue the potential of the investigated compounds (both in fractions and individual isolates) using the MTT assay. The total extract (T1) displayed the most significant activity against SARS-CoV-2 with IC50 = 29.36 µg/mL. Besides, the fractions (Fr1 and Fr3) showed good activity against the SARS-CoV-2 with IC50 values of 70.42, and 73.09 µg/mL, respectively. Then, the SARS-CoV-2 Mpro inhibitory assay was utilized to emphasize the inhibitory potential of the investigated isolates. MJN, JMD, and IJM candidates displayed prominent Mpro inhibitory potentials with IC50 = 30.44, 30.24, and 56.25 µM, respectively. Moreover, molecular docking of the identified seven compounds against the Mpro of SARS-CoV-2 showed that the five secoiridoids achieved superior results. MJN, JSM, IJM, and JMD showed higher affinities towards the Mpro target compared to the co-crystallized antagonist. Furthermore, the most active complexes (MJN, JSM, IJM, and JMD-Mpro) were subjected to MD simulations run for 150 ns and MM-GBSA calculations, compared to the co-crystallized inhibitor (O6K-Mpro). Finally, the SAR study clarified that JMD achieved the best anti-SARS-CoV-2 Mpro activity followed by MJN.Communicated by Ramaswamy H. Sarma.

HIGHLIGHTSSeven isolates from J. humile, besides different extracts, were examined both in vitro and in silico.Anti-SARS-CoV-2 using the MTT assay and anti-SARS-CoV-2 Mpro inhibitory assay were performed.Compounds MJN, JMD, and IJM displayed prominent SARS-CoV-2 Mpro inhibition.Molecular docking, molecular dynamics simulations, and MM-GBSA calculations were carried out.SAR study was conducted on the isolated compounds.

Partnering essential oils with antibiotics: proven therapies against bovine Staphylococcus aureus mastitis.

Introduction: There is an urgent need to develop therapeutic options for biofilm-producing Staphylococcus aureus (S. aureus). Therefore, the renewed interest in essential oils (EOs), especially carvacrol, linalool and eugenol, has attracted the attention of our research group. Methods: Multidrug resistance and multivirulence profiles in addition to biofilm production of S. aureus strains isolated from cows with mastitis were evaluated using both phenotypic and genotypic methods. The antimicrobial and antibiofilm activities of EOs were tested using both in vitro and molecular docking studies. Moreover, the interactions between commonly used antibiotics and the tested EOs were detected using the checkerboard method. Results: We found that all our isolates (n= 37) were biofilm methicillin resistant S. aureus (MRSA) producers and 40.5% were vancomycin resistant S. aureus (VRSA). Unfortunately, 73 and 43.2% of the recovered MRSA isolates showed multidrug resistant (MDR) and multivirulence patterns, respectively. The antimicrobial activities of the tested EOs matched with the phenotypic evaluation of the antibiofilm activities and molecular docking studies. Linalool showed the highest antimicrobial and antibiofilm activities, followed by carvacrol and eugenol EOs. Fortunately, synergistic interactions between the investigated EOs and methicillin or vancomycin were detected with fractional inhibitory concentration index (FICI) values ≤ 0.5. Moreover, the antimicrobial resistance patterns of 13 isolates changed to sensitive phenotypes after treatment with any of the investigated EOs. Treatment failure of bovine mastitis with resistant S. aureus can be avoided by combining the investigated EOs with available antimicrobial drugs. Conclusion: We hope that our findings can be translated into a formulation of new pharmaceutical dosage forms against biofilm-producing S. aureus pathogens.

Bioanalytical LC-MS/MS method for simultaneous estimation of atorvastatin, its major active metabolites and ezetimibe.

Background: Hyperlipidemia is one of the most common chronic diseases encountered globally, and atorvastatin (ATV) is mainly metabolized into two major active metabolites. Methodology: Hence, we aimed to estimate ATV and ezetimibe (EZE) simultaneously in the presence of ATV major and active metabolites using a validated LC-MS/MS method. Conclusion: The proposed method was linear (r2 >0.99), accurate (92.02-109.94%) and precise (CV% ≤14) over the concentration range of 0.50-120 ng/ml, 0.20-48 ng/ml, 0.50-120 ng/ml and 0.20-48 ng/ml for ATV, EZE, 2-hydroxy ATV and 4-hydroxy ATV, respectively. The applied liquid-liquid extraction gave rise to reliable extraction recoveries of 84.91 ± 1.14%, 85.20 ± 1.62%, 85.46 ± 0.41% and 105.46 ± 2.35% for ATV, EZE, 2-hydroxy ATV and 4-hydroxy ATV, respectively.

Analysis of the ternary antiretroviral therapy dolutegravir, lamivudine and abacavir using UV spectrophotometry and chemometric tools.

Herein, a simple spectrophotometric method coupled with chemometric techniques i.e. partial least square (PLS) and genetic algorithm (GA) were utilized for the simultaneous determination of the vital ternary antiretroviral therapy dolutegravir (DTG), lamivudine (LMV), and abacavir (ACV) in their combined dosage form. Calibration (25 samples) and validation (13 samples) sets were prepared for these drugs at different concentrations via implementing partial factorial experimental designs. The zero order UV spectra of calibration and validation sets were measured and then subjected for further chemometric analysis. Partial least squares with/without variable selection procedures i.e. genetic algorithm (GA) were utilized to untangle the UV spectral overlapping of these mixtures. Cross-validation and external validation methods were applied to compare the performance of these chemometric techniques in terms of accuracy and predictive abilities. It was found that six latent variables were optimum for modelling DTG, four latent variables for modelling LMV and three latent variables for modelling ACV. Although, good recoveries with prompt predictive ability were attained by these PLS, GA-PLS showed better analytical performance owing to its capability to remove redundant variables i.e. the number of absorbance variables have been reduced to about 21-29%. The proposed chemometric methods can be reliably applied for simultaneous determination of DTG, LMV, and ACV in their laboratory prepared mixtures and pharmaceutical preparation posing these chemometric methods as worthy and substantial analytical tools in in-process testing and quality control analysis of many antiretroviral pharmaceutical preparations.

In a search for potential drug candidates for combating COVID-19: computational study revealed salvianolic acid B as a potential therapeutic targeting 3CLpro and spike proteins.

The global prevalence of COVID-19 disease and the overwhelming increase in death toll urge scientists to discover new effective drugs. Although the drug discovery process is a challenging and time-consuming, fortunately, the plant kingdom was found to have many active therapeutics possessing broad-spectrum antiviral activity including those candidates active against severe acute respiratory syndrome coronaviruses (SARS-CoV). Herein, nine traditional Chinese medicinal plant constituents from different origins (Glycyrrhizin 1, Lycorine 2, Puerarin 3, Daidzein 4, Daidzin 5, Salvianolic acid B 6, Dihydrotanshinone I 7, Tanshinone I 8, Tanshinone IIa 9) previously reported to exhibit antiviral activity against SARS-CoV were virtually screened in silico (molecular docking) as potential inhibitors of SARS-CoV-2 target proteins. The tested medicinal plant compounds were in silico screened for their activity against two key SARS-CoV-2 target proteins; 3CLpro, and Spike binding-domain proteins. Among the tested medicinal plant compounds, Salvianolic acid B 6 (Sal-B) showed promising binding affinities against the two specified SARS-CoV-2 target proteins compared to the reference standards used. Hence molecular dynamics simulations followed by calculating the free-binding energy were carried out for Sal-B providing information on its affinity, stability, and thermodynamic behavior within the two SARS-CoV-2 target proteins as well as key ligand-protein binding aspects. Besides, the quantum mechanical calculations showed that Sal-B can adopt different conformations due to the existence of various rotatable bonds. Therefore, the enhanced antiviral activity of Sal-B among other studied compounds can be also attributed to the structural flexibility of Sal-B. Our study gives an explanation of the structure activity relationship required for targeting SARS-CoV-2 3CLpro and Spike proteins and also facilitates the future design and synthesis of new potential drugs exhibiting better affinity and specificity. Besides, an ADME study was carried out on screened compounds and reference controls revealing their pharmacokinetics properties.Communicated by Ramaswamy H. Sarma.

In Silico and In Vitro Studies for Benzimidazole Anthelmintics Repurposing as VEGFR-2 Antagonists: Novel Mebendazole-Loaded Mixed Micelles with Enhanced Dissolution and Anticancer Activity.

Cancer is a leading cause of death worldwide and its incidence is unfortunately anticipated to rise in the next years. On the other hand, vascular endothelial growth factor receptor 2 (VEGFR-2) is highly expressed in tumor-associated endothelial cells, where it affects tumor-promoting angiogenesis. Therefore, VEGFR-2 is considered one of the most promising therapeutic targets for cancer treatment. Furthermore, some FDA-approved benzimidazole anthelmintics have already shown potential anticancer activities. Therefore, repurposing them against VEGFR-2 can provide a rapid and effective alternative that can be implicated safely for cancer treatment. Hence, 13 benzimidazole anthelmintic drugs were subjected to molecular docking against the VEGFR-2 receptor. Among the tested compounds, fenbendazole (FBZ, 1), mebendazole (MBZ, 2), and albendazole (ABZ, 3) were proposed as potential VEGFR-2 antagonists. Furthermore, molecular dynamics simulations were carried out at 200 ns, giving more information on their thermodynamic and dynamic properties. Besides, the anticancer activity of the aforementioned drugs was tested in vitro against three different cancer cell lines, including liver cancer (HUH7), lung cancer (A549), and breast cancer (MCF7) cell lines. The results depicted potential cytotoxic activity especially against both HUH7 and A549 cell lines. Furthermore, to improve the aqueous solubility of MBZ, it was formulated in the form of mixed micelles (MMs) which showed an enhanced drug release with better promising cytotoxicity results compared to the crude MBZ. Finally, an in vitro quantification for VEGFR-2 concentration in treated HUH7 cells has been conducted based on the enzyme-linked immunosorbent assay. The results disclosed that FBZ, MBZ, and ABZ significantly (p < 0.001) reduced the concentration of VEGFR-2, while the lowest inhibition was achieved in MBZ-loaded MMs, which was even much better than the reference drug sorafenib. Collectively, the investigated benzimidazole anthelmintics could be encountered as lead compounds for further structural modifications and thus better anticancer activity, and that was accomplished through studying their structure-activity relationships.

In vitro and computational insights revealing the potential inhibitory effect of Tanshinone IIA against influenza A virus.

Seasonal human influenza is a serious respiratory infection caused by influenza viruses that can be found all over the world. Type A influenza is a contagious viral infection that, if left untreated, can lead to life-threatening consequences. Fortunately, the plant kingdom has many potent medicines with broad-spectrum antiviral activity. Herein, six plant constituents, namely Tanshinone IIA 1, Carnosic acid 2, Rosmarinic acid 3, Glycyrrhetinic acid 4, Baicalein 5, and Salvianolic acid B 6, were screened for their antiviral activities against H1N1 virus using in vitro and in silico approaches. Hence, their anti-influenza activities were tested in vitro to determine inhibitory concentration 50 (IC50) values after measuring their CC50 values using MTT assay on MDCK cells. Interestingly, Tanshinone IIA (TAN) 1 was the most promising member with CC50 = 9.678 µg/ml. Moreover, the plaque reduction assay carried on TAN 1 revealed promising viral inhibition percentages of 97.9%, 95.8%, 94.4%, and 91.7% using concentrations 0.05 µg/µl, 0.025 µg/µl, 0.0125 µg/µl, and 0.006 µg/µl, respectively. Furthermore, in silico molecular docking disclosed the superior affinities of Salvianolic acid B (SAL) 6 towards both surface glycoproteins of influenza A virus (namely, hemagglutinin (HA) and neuraminidase (NA)). The docked complexes of both SAL and TAN inside HA and NA receptor pockets were selected for 100 ns MD simulations followed by MM-GBSA binding free energy calculation to confirm the docking results and give more insights regarding the stability of both compounds inside influenza mentioned receptors, respectively. The selection criteria of the previously mentioned complexes were based on the fact that SAL showed the highest docking scores on both viral HA and NA glycoproteins whereas TAN achieved the best inhibitory activity on the other hand. Finally, we urge more advanced preclinical and clinical research, particularly for TAN, which could be used to treat the human influenza A virus effectively.