Impact of Eucalyptus maculata Hook resin exudate constituents on reducing COX-2 gene expression: In-vivo anti-inflammatory, molecular docking and dynamics studies.

ETHNOPHARMACOLOGICAL RELEVANCE: Eucalyptus maculata Hook from the Myrtaceae family is a native Australian plant that is frequently cultivated in Egypt. Many Eucalyptus species, including E. maculata, were widely used by the Dharawal, the indigenous Australian people, for their anti-inflammatory properties. AIM OF THE STUDY: The purpose of this study was to determine the anti-inflammatory activity of the ethanol extract of E. maculata resin exudate, its methylene chloride and n-butanol fractions, as well as the isolated compounds. MATERIALS AND METHODS: the ethanol extract was partitioned by methylene chloride, and n-butanol saturated with water. The fractions were chromatographed to isolate pure compounds. In-vivo anti-inflammatory activity of the ethanol extract, the fractions at a dose of 200 mg/kg, and the isolated compounds (20 mg/kg) was estimated using carrageenan-induced rat paws edema method against indomethacin (20 mg/kg). The activity was supported by histopathological and biochemical parameters. RESULTS: Three isolated compounds were identified as aromadendrin (C1), 7-O-methyl aromadendrin (C2), and naringenin (C3). Our findings demonstrated that the tested fractions significantly reduced the paw edema starting from the 3rd to the 5th hour as compared to the positive control, compounds C2 and C3 showed the greatest significant reduction in paw edema. The ethanol extract, fractions, C2, and C3 demonstrated an anti-inflammatory potential through reducing the levels of TNF-α, IL-6, and PGE2, as well as COX-2 protein expression compared to the negative control. These results were supported by molecular docking, which revealed that the isolated compounds had high affinity to target COX-1 and COX-2 active sites with docking scores ranging from -7.3 to -9.6 kcal mol-1 when compared to ibubrofen (-7.8 and -7.4 kcal mol-1, respectively). Molecular dynamics simulations were also performed and confirmed the docking results. CONCLUSION: The results supported the traditional anti-inflammatory potency of E. maculata Hook, and the biochemical mechanisms underlying this activity were highlighted, opening up new paths for the development of potent herbal anti-inflammatory medicine. Finally, our findings revealed that E. maculata resin constituents could be considered as promising anti-inflammatory drug candidates.

Isatin-pyrimidine hybrid derivatives as enoyl acyl carrier protein reductase (InhA) inhibitors against Mycobacterium tuberculosis.

Tuberculosis is a worldwide problem that impose a burden on the economy due to continuous development of resistant strains. The development of new antitubercular drugs is a need and can be achieved through inhibition of druggable targets. Mycobacterium tuberculosis enoyl acyl carrier protein (ACP) reductase (InhA) is an important enzyme for Mycobacterium tuberculosis survival. In this study, we report the synthesis of isatin derivatives that could treat TB through inhibition of this enzyme. Compound 4l showed IC50 value (0.6 ± 0.94 µM) similar to isoniazid but is also effective against MDR and XDR Mycobacterium tuberculosis strains (MIC of 0.48 and 3.9 µg/mL, respectively). Molecular docking studies suggest that this compound binds through the use of relatively unexplored hydrophobic pocket in the active site. Molecular dynamics was used to investigate and support the stability of 4l complex with the target enzyme. This study paves the way for the design and synthesis of novel antitubercular drugs.

Evaluation of antiviral activity of Carica papaya leaves against SARS-CoV-2 assisted by metabolomic profiling.

The COVID-19 pandemic caused a huge health crisis all over the globe. SARS-CoV-2 is the virus responsible for the disease and it is highly contagious leaving millions of confirmed infected cases and a dangerous death toll. Carica papaya is a tropical plant known for its antiviral activity since it possesses different classes of compounds that are believed to combat various viral classes. In this study, the extracts prepared from C. papaya leaves cultivated in Egypt were evaluated for their anti-SARS-CoV-2 activity using crystal violet assay and for their cytotoxicity through MTT assay. The total methanolic extract, n-hexane, ethyl acetate, and n-butanol fractions of papaya leaves were used in the study and the results revealed that the n-hexane fraction has a high anti-SARS-CoV-2 activity with an IC50 value = 1.98 µg mL-1. Moreover, it also showed a high selectivity index value = 104.7. Dereplication of the secondary metabolites in the crude methanolic extract of C. papaya leaves revealed the presence of different classes of compounds including sterols, terpenes, fatty acid, alkaloids and flavonoids that are known to possess antiviral activities against various classes of viruses. The current study was assisted by molecular docking, molecular dynamics simulation and MM-PBSA calculations for the annotated compounds against 6 SARS-CoV-2 target proteins. The results of these in silico-based investigations showed high to moderate binding on the targeted proteins. This postulation may instigate further research studies concerning the compounds responsible for this high anti-SARS-CoV-2 activity of the n-hexane fraction of C. papaya leaves.

Tackling Microbial Resistance with Isatin-Decorated Thiazole Derivatives: Design, Synthesis, and in vitro Evaluation of Antimicrobial and Antibiofilm Activity.

Introduction: Antibiotic resistance is a global threat that has been increasing recently, especially with antibiotic overuse and misuse. The search for new antibiotics is becoming more and more indispensable. Methods: Design and synthesis of isatin derivatives as surrogates of SB-239629, a bacterial tyrosine-tRNA synthetases (TyrRS) inhibitor. The newly synthesized compounds were screened for their antimicrobial and antibiofilm activities. Docking studies were used to investigate potential binding modes of these compounds with TyrRS. Results and Discussion: Newly synthesized isatin-decorated thiazole derivatives (7b, 7d, and 14b) have shown potent antimicrobial activities against E. coli, a representative of gram-negative bacteria. Also, 7f showed the best activity against Methicillin Resistant Staphylococcus aureus (MRSA). In addition, 7h and 11f were found to have antifungal activities against Candida albicans equivalent to that of the reference Nystatin. All the new isatin derivatives with antimicrobial activities were found to exhibit strong biofilm distortion effects at half their minimum inhibitory concentrations (MIC). Moreover, thiazole derivatives 11a-f showed promising biofilm formation inhibition. Finally, molecular docking studies were used to investigate possible binding modes of target compounds with S. aureus and E. coli TyrRS. Conclusion: The novel isatin-decorated thiazole derivatives show strong antimicrobial and antifungal activities with potential action on TyrRS.

Remdesivir analog as SARS-CoV-2 polymerase inhibitor: virtual screening of a database generated by scaffold replacement.

By the end of 2019, a novel strain of the corona viral family named SARS-CoV-2 emerged in Wuhan, China and started to spread worldwide causing one of the most dangerous lethal pandemics. Researchers utilized various reported inhibitors and drug databases for virtual screening analysis against this novel strain. Later on, they succeeded to fish and repurpose remdesivir, an antiviral nucleotide analogue that inhibits RNA polymerase of the Ebola virus, as a promising candidate against SARS-CoV-2. In this study, we used the interactions of the co-crystallized metabolite of remdesivir with SARS-CoV-2 RdRp isozyme (PDB 7BV2) to design an analog with potential extra activity. This design was based on a scaffold replacement of a pyrrolotriazine moiety. This design was guided by a generated structure-based pharmacophore. The database generated from scaffold replacement was subjected to molecular docking and molecular dynamics simulations within the active site of SARS-CoV-2 RdRp (PDB 7BV2) to suggest HA-130383 and HA-130384 as potential lead compounds.

Neuroprotective repositioning and anti-tau effect of carvedilol on rotenone induced neurotoxicity in rats: Insights from an insilico& in vivo anti-Parkinson's disease study.

Current treatments for Parkinson's Disease (PD) only provide symptomatic relief; however, they don't delay the disease progression, hence new treatment options should be considered. Carvedilol is a nonselective ß & α1 blocker with additional effects as an antioxidant, anti-inflammatory and neuro protective properties. In this research, an insilico study was conducted to primarily evaluate carvedilol as an anti-parkinsonian and anti-tau protein target. PASS prediction was performed followed by a docking study of carvedilol. Carvedilol yielded promising results and forward guided this study onto its in vivo evaluation. The in vivo study aimed to assess the neuro-protective effects of carvedilol in rotenone-induced rat model of PD and investigate the potential underlying mechanisms. The effects of carvedilol (2.5, 5, and 10 mg/kg) on the measured parameters of open field, catalepsy, Y-maze tests as well as brain histology, and tyrosine hydroxylase (TH) were evaluated. The effective doses (5 and 10 mg/kg) were further tested for their potential anti-tau protein effects. Carvedilol (5 and 10 mg/kg) prevented rotenone-induced motor deficits, spatial memory dysfunction, and histological damage. Additionally, carvedilol significantly inhibited rotenone-induced decrease in TH expression in the striata of the rats. These effects were associated with reduction of rotenone-induced neuro-inflammation, microglial activation and release of glial fibrillary acidic protein (GFAP), along with reduction in N-methyl-D-aspartate receptors activation, alpha-synculein and phospho-Tau (P-Tau) protein expression. Carvedilol also reduced tau protein hyper-phosphosrylation by Glycogen synthase 3ß (GSK 3ß) inhibition and Phosphoinositide 3-kinase (PI3K) stimulation. Collectively, these results suggest that carvedilol might be a possible candidate for management of PD.

Antiulcer Potential of Psidium guajava Seed Extract Supported by Metabolic Profiling and Molecular Docking.

One of the most severe human health problems is gastric ulceration. The main aim of our study is to explore the gastroprotective effect of the Psidium guajava seeds extract (PGE). Metabolic profiling based on LC-HRMS for the extract led to the dereplication of 23 compounds (1-23). We carried out a gastric ulcer model induced by indomethacin in male albino rats in vivo and the extract of PGE was investigated at a dose of 300 mg/kg in comparison to cimetidine (100 mg/kg). Furthermore, the assessment of gastric mucosal lesions and histopathology investigation of gastric tissue was done. It has been proved that Psidium guajava seeds significantly decreased the ulcer index and protected the mucosa from lesions. The antiulcer effect of Psidium guajava seed extract, which has the power of reducing the ensuing inflammatory reactions, can counteract the inflammation induced by indomethacin by the downregulation of relative genes expression (IL-1ß, IL-6, and TNF-α). Moreover, PGE significantly downregulated the increased COX-2, TGF-ß, and IGF-1 relative genes expression, confirming its beneficial effect in ulcer healing. Moreover, the possible PGE antioxidant potential was determined by in vitro assays using hydrogen peroxide and superoxide radical scavenging and revealed high antioxidant potential. Additionally, on the putatively annotated metabolites, an in silico study was conducted, which emphasized the extract's antiulcer properties might be attributed to several sterols such as stigmasterol and campesterol. The present study provided evidence of Psidium guajava seeds considered as a potential natural gastroprotective agent.

Synthesis and Antiproliferative Activity of a New Series of Mono- and Bis(dimethylpyrazolyl)-s-triazine Derivatives Targeting EGFR/PI3K/AKT/mTOR Signaling Cascades.

Here, we synthesized a newseries of mono- and bis(dimethylpyrazolyl)-s-triazine derivatives. The synthetic methodology involved the reaction of different mono- and dihydrazinyl-s-triazine derivatives with acetylacetone in the presence of triethylamine to produce the corresponding target products in high yield and purity. The antiproliferative activity of the novel mono- and bis(dimethylpyrazolyl)-s-triazine derivatives was studied against three cancer cell lines, namely, MCF-7, HCT-116, and HepG2. N-(4-Bromophenyl)-4-(3,5-dimethyl-1H-pyrazol-1-yl)-6-morpholino-1,3,5-triazin-2-amine 4f, N-(4-chlorophenyl)-4,6-bis(3,5-dimethyl-1H-pyrazol-1-yl)-1,3,5-triazin-2-amine 5c, and 4,6-bis(3,5-dimethyl-1H-pyrazol-1-yl)-N-(4-methoxyphenyl)-1,3,5-triazin-2-amine 5d showed promising activity against these cancer cells: 4f [(IC50 = 4.53 ± 0.30 µM (MCF-7); 0.50 ± 0.080 µM (HCT-116); and 3.01 ± 0.49 µM (HepG2)]; 5d [(IC50 = 3.66 ± 0.96 µM (HCT-116); and 5.42 ± 0.82 µM (HepG2)]; and 5c [(IC50 = 2.29 ± 0.92 µM (MCF-7)]. Molecular docking studies revealed good binding affinity with the receptor targeting EGFR/PI3K/AKT/mTOR signaling cascades. Compound 4f exhibited potent EGFR inhibitory activity with an IC50 value of 61 nM compared to that of Tamoxifen (IC50 value of 69 nM), with EGFR inhibition of 83 and 84%, respectively, at a concentration of 10 µM. Interestingly, 4f showed remarkable PI3K/AKT/mTOR inhibitory activity with 0.18-, 0.27-, and 0.39-fold decrease in their concentration (reduction in controls from 6.64, 45.39, and 86.39 ng/mL to 1.24, 12.35, and 34.36 ng/mL, respectively). Hence, the synthetic 1,3,5-triazine derivative 4f exhibited promising antiproliferative activity in HCT-116 cells through apoptosis induction by targeting the EGFR and its downstream pathway.

Novel 2-(5-Aryl-4,5-Dihydropyrazol-1-yl)thiazol-4-One as EGFR Inhibitors: Synthesis, Biological Assessment and Molecular Docking Insights.

Introduction: Epidermal growth factor receptor (EGFR) regulates several cell functions which include cell growth, survival, multiplication, differentiation, and apoptosis. Currently, EGFR kinase inhibitors are of increasing interest as promising targeted antitumor therapeutic agents. Methods: Different thiazolyl-pyrazoline derivatives (7a-o) were synthesized and were first tested for anti-proliferative effect towards the A549 lung cancer cell line and the T-47D breast cancer cell line in MTT assay. Thereafter, thiazolyl-pyrazolines (7b, 7g, 7l, and 7m) were subsequently evaluated for their PK inhibition for EGFR. Moreover, representative promising derivatives (7g and 7m) in cytotoxic and PK inhibition assays were tested to investigate their impact on the apoptosis and cell cycle phases in T-47D cells in order to explore more insights into the antitumor actions of the target thiazolyl-pyrazolines. Furthermore, docking studies were accomplished to evaluate the patterns of binding of thiazolyl-pyrazolines 7b, 7g, 7l, and 7m in the EGFR active pocket (PDB ID: 1M17). Results: Testing the thiazolyl pyrazoline compounds 7a-o on A549 and T-47D cell lines showed IC50 arrays between 3.92 and 89.03 µM, and between 0.75 and 77.10 µM, respectively. Also, the tested thiazolyl-pyrazolines (7b, 7g, 7l, and 7m) demonstrated significant sub-micromolar EGFR inhibitory actions with IC50 values 83, 262, 171 and 305 nM, respectively, in comparison to erlotinib (IC50 =57 nM). Discussion: Generally, it was observed that the tested thiazolyl pyrazolines showed more potent antiproliferative activity toward breast cancer cells T-47D than toward lung cancer cell lines A549. In particular, thiazolyl pyrazolines 7g and 7m showed the best activity against A549 cells (IC50 = 3.92 and 6.53 µM) and T-47D cells (IC50 = 0.88 and 0.75 µM). Compounds 7g and 7m provoked a sub-G1 phase arrest and cell apoptosis which are in agreement with the expected outcome of EGFR inhibition. Finally, the molecular docking of 7g and 7m in the active site of EGFR revealed a common binding pattern similar to that of erlotinib which involves the accommodation of the 1,3 thiazol-4-one ring and pyrazoline ring of target compounds in the binding region of erlotinib's quinazoline ring and anilino moiety.

Anti-Inflammatory, Antiallergic and COVID-19 Main Protease (Mpro) Inhibitory Activities of Butenolides from a Marine-Derived Fungus Aspergillus costaricaensis.

Amid the current COVID-19 pandemic, the emergence of several variants in a relatively high mutation rate (twice per month) strengthened the importance of finding out a chemical entity that can be potential for developing an effective medicine. In this study, we explored ethyl acetate (EtOAc) extract of a marine-derived fungus Aspergillus cosatricaensis afforded three butenolide derivatives, butyrolactones I, VI and V (1-3), two naphtho-γ-pyrones, TMC-256 A1 (4) and rubrofusarin B (5) and methyl p-hydroxyphenyl acetate (6). Structure identification was unambiguously determined based on exhaustive spectral analyses including 1D/2D NMR and mass spectrometry. The isolated compounds (1-6) were assessed for their in vitro anti-inflammatory, antiallergic, elastase inhibitory activities and in silico SARS-CoV-2 main protease (Mpro). Results exhibited that only butenolides (1 and 2) revealed potent activities similar to or more than reference drugs unlike butyrolactone V (3) suggesting them as plausible chemical entities for developing lead molecules.

Biodiversity of N-acyl homoserine lactonase (aiiA) gene from Bacillus subtilis.

Microorganisms rely on the benefit of using chemical signals called autoinducers (AIs) as a connection matter in term of population, this mechanism is known as quorum sensing (QS). Quorum sensing is responsible for formation of biofilm together with virulence in bacteria. The most known QS molecule is N-acyl homoserine lactones (AHLs). A lot of degrading enzymes including lactonases that open the AHL ring and acylases that breakdown its acyl side chain can degrade or inactivate AHL. Due to similarity in lactone ring structure among AHLs it is susceptible to most of lactonases. Bacillus species are among the most promising bacteria producing AHL-lactonase. The aim of the work is to identify and study the diversity of the AHL-Lactonase gene among different Bacillus subtilis as a promising Quorum Quenching (QQ) strategy to prevent bacterial infections and biofilm formation. The AHL-lactonase (aiiA) gene of 64 B. subtilis isolates was amplified and sequenced followed by multiple sequence alignment of the translated amino acid sequences, homology modeling and docking study. An expected PCR product of about 750 base pair was detected in 22 B. subtilis isolates, and the results revealed that the isolates' sequences showed identity ranged between 97.61% and 99.47% with those in the NCBI GenBank database with 100% query coverage and 0.0 E-value. In addition, the results revealed high level of identity between many aiiA gene sequences of our isolates as they were closely related to the same sequences to many sequences of the NCBI GenBank database. The alignment of the amino acid sequences from the 22 B. subtilis isolates indicated that 84.4% of the amino acid residues were conserved between the aligned sequences. Docking of the co-crystalized ligand to wildtype and H109Y mutated protein showed a significant reduction of docking score for the mutated protein. This result indicate that this mutation might affect recognition or at least kinetics of these enzymes and hence their roles in quorum-quenching.

Multitarget in silico studies of Ocimum menthiifolium, family Lamiaceae against SARS-CoV-2 supported by molecular dynamics simulation.

The novel strain of human coronavirus, emerged in December 2019, which has been designated as SARS-CoV-2, causes a severe acute respiratory syndrome. Since then, it has arisen as a serious threat to the world public health. Since no approved vaccines or drugs has been found to efficiently stop the virulent spread of the virus, progressive inquiries targeting these viruses are urgently needed, especially those from plant sources. Metabolic profiling using LC-HR-ESI-MS of the butanol extract of Ocimum menthiifolium (Lamiaceae) aerial parts yielded 10 compounds including flavonoids, iridoids and phenolics. As it has been previously reported that some flavonoids can be used as anti-SARS drugs by targeting SARS-CoV-1 3CLpro, we chose to examine 14 flavonoids (detected by metabolomics and other compounds isolated via several chromatographic techniques). We investigated their potential binding interactions with the 4 main SARS-CoV-2 targets: Mpro, nsp16/nsp10 complex, ACE2-PD and RBD-S-protein via molecular docking. Docking results indicated that the nsp16/nsp10 complex has the best binding affinities where the strongest binding was detected with apigenin-7-O-rutinoside, prunin and acaciin with -9.4, -9.3 and -9.3 kcal/mol binding energy, respectively, compared to the control (SAM) with -8.2 kcal/mol. Furthermore, the stability of these complexes was studied using molecular dynamics of 150 ns, which were then compared to their complexes in the other three targets. MM-PBSA calculations suggested the high stability of acaciin-nsp16 complex with binding energy of -110 kJ/mol. This study sheds light on the structure-based design of natural flavonoids as anti-SARS-CoV-2 drugs targeting the nsp16/10 complex.Communicated by Ramaswamy H. Sarma.

Metabolomic profiling of three Araucaria species, and their possible potential role against COVID-19.

The COVID-19 pandemic in Egypt is a part of the worldwide global crisis of coronavirus 2 (SARS-CoV-2). The contagious life-threatening condition causes acute respiratory syndrome. The present study aimed to assess the compounds identified by LC-MS of the methanolic leaves extracts from three conifers trees cultivated in Egypt (Araucaria bidwillii, Araucaria. cunninghamii and Araucaria heterophylla) via docking technique as potential inhibitor of COVID-19 virus on multiple targets; viral main protease (Mpro, 6LU7), non-structural protein-16 which is a methyl transferase (nsp16, 6W4H) and RNA dependent RNA polymerase (nsp12, 7BV2). Among the three targets, nsp16 was the best target recognized by the tested compounds as can be deduced from docking studies. Moreover, the methanolic extract of A. cunninghamii showed the highest radical-scavenging activity using (DPPH test) with 53.7 µg/mL comparable to ascorbic acid with IC50 = 46 µg/mL The anti-inflammatory potential carried using enzyme linked immunoassay showed the highest activity for A. cunninghamii and A. bidwillii followed by A. heterophylla with IC50 = 23.20 ± 1.17 µg/mL, 82.83 ± 3.21 µg/mL and 221.13 ± 6.7 µg/mL, respectively (Celecoxib was used as a standard drug with IC50 = 141.92 ± 4.52 µg/mL). Moreover, a molecular docking study was carried for the LC-MS annotated metabolites to validate their anti-inflammatory inhibitory effect using Celecoxib as a reference compound and showed a high docking score (-7.7 kcal/mol) for Octadecyl (E) P-coumarate and (-7.3 kcal/mol) for secoisolariciresinol rhamnoside.Communicated by Ramaswamy H. Sarma.

2-Arylquinolines as novel anticancer agents with dual EGFR/FAK kinase inhibitory activity: synthesis, biological evaluation, and molecular modelling insights.

In this study, different assortments of 2-arylquinolines and 2,6-diarylquinolines have been developed. Recently, we have developed a new series of 6,7-dimethoxy-4-alkoxy-2-arylquinolines as Topoisomerase I (TOP1) inhibitors with potent anticancer activity. Utilising the SAR outputs from this study, we tried to enhance anticancer and TOP1 inhibitory activities. Though target quinolines demonstrated potent antiproliferative effect, specifically against colorectal cancer DLD-1 and HCT-116, they showed weak TOP1 inhibition which may be attributable to their non-coplanarity. Thereafter, screening against kinase panel revealed their dual inhibitory activity against EGFR and FAK. Quinolines 6f, 6h, 6i, and 20f were the most potent EGFR inhibitors (IC50s = 25.39, 20.15, 22.36, and 24.81 nM, respectively). Meanwhile, quinolines 6f, 6h, 6i, 16d, and 20f exerted the best FAK inhibition (IC50s = 22.68, 14.25, 18.36, 17.36, and 15.36 nM, respectively). Finally, molecular modelling was employed to justify the promising EGFR/FAK inhibition. The study outcomes afforded the first reported quinolines with potent EGFR/FAK dual inhibition.

Marine-Based Candidates as Potential RSK1 Inhibitors: A Computational Study.

Manzamines are chemically related compounds extracted from the methanolic extract of Acanthostrongylophora ingens species. Seven compounds were identified by our research group and are being characterized. As their biological target is unknown, this work is based on previous screening work performed by Mayer et al., who revealed that manzamine A could be an inhibitor of RSK1 kinase. Within this work, the RSK1 N-terminal kinase domain is exploited as a target for our work and the seven compounds are docked using Autodock Vina software. The results show that one of the most active compounds, Manzamine A N-oxide (5), with an IC50 = 3.1 µM, displayed the highest docking score. In addition, the compounds with docking scores lower than the co-crystalized ligand AMP-PCP (-7.5 and -8.0 kcal/mol) for ircinial E (1) and nakadomarin A (7) were found to be inferior in activity in the biological assay. The docking results successfully managed to predict the activities of four compounds, and their in silico results were in concordance with their biological data. The ß-carboline ring showed noticeable receptor binding, which could explain its reported biological activities, while the lipophilic side of the compound was found to fit well inside the hydrophobic active site.

Anti-Inflammatory, Antiallergic, and COVID-19 Main Protease (Mpro) Inhibitory Activities of Butenolides from a Marine-Derived Fungus Aspergillus terreus.

In December 2020, the U.K. authorities reported to the World Health Organization (WHO) that a new COVID-19 variant, considered to be a variant under investigation from December 2020 (VUI-202012/01), was identified through viral genomic sequencing. Although several other mutants were previously reported, VUI-202012/01 proved to be about 70% more transmissible. Hence, the usefulness and effectiveness of the newly U.S. Food and Drug Administration (FDA)-approved COVID-19 vaccines against these new variants are doubtfully questioned. As a result of these unexpected mutants from COVID-19 and due to lack of time, much research interest is directed toward assessing secondary metabolites as potential candidates for developing lead pharmaceuticals. In this study, a marine-derived fungus Aspergillus terreus was investigated, affording two butenolide derivatives, butyrolactones I (1) and III (2), a meroterpenoid, terretonin (3), and 4-hydroxy-3-(3-methylbut-2-enyl)benzaldehyde (4). Chemical structures were unambiguously determined based on mass spectrometry and extensive 1D/2D NMR analyses experiments. Compounds (1-4) were assessed for their in vitro anti-inflammatory, antiallergic, and in silico COVID-19 main protease (Mpro) and elastase inhibitory activities. Among the tested compounds, only 1 revealed significant activities comparable to or even more potent than respective standard drugs, which makes butyrolactone I (1) a potential lead entity for developing a new remedy to treat and/or control the currently devastating and deadly effects of COVID-19 pandemic and elastase-related inflammatory complications.

Synthesis, in vitro biological investigation, and molecular dynamics simulations of thiazolopyrimidine based compounds as corticotrophin releasing factor receptor-1 antagonists.

Corticotrophin releasing factor receptor-1 (CRFR1) is a potential target for treatment of depression and anxiety through modifying stress response. A series of new thiazolo[4,5-d]pyrimidine derivatives were designed, prepared and biologically evaluated as potential CRFR1 antagonists. Four compounds produced more than fifty percent inhibition in the [125I]-Tyr0-sauvagine specific binding assay. Assessment of binding affinities revealed that compound (3-(2,4-dimethoxyphenyl)-7-(dipropylamino)-5-methylthiazolo[4,5-d]pyrimidin-2(3H)-one) 8c was the best candidate with highest binding affinity (Ki = 32.1 nM). Further evaluation showed the ability of compound 8c to inhibit CRF induced cAMP accumulation in a dose response manner. Docking and molecular dynamics simulations were used to investigate potential binding modes of synthesized compounds as well as the stability of 8c-CRFR1 complex. These studies suggest similar allosteric binding of 8c compared to that of the co-crystalized ligand CP-376395 in 4K5Y pdb file.

Transforming iodoquinol into broad spectrum anti-tumor leads: Repurposing to modulate redox homeostasis.

We managed to repurpose the old drug iodoquinol to a series of novel anticancer 7-iodo-quinoline-5,8-diones. Twelve compounds were identified as inhibitors of moderate to high potency on an inhouse MCF-7 cell line, of which 2 compounds (5 and 6) were capable of reducing NAD level in MCF-7 cells in concentrations equivalent to half of their IC50s, potentially due to NAD(P)H quinone oxidoreductase (NQO1) inhibition. The same 2 compounds (5 and 6) were capable of reducing p53 expression and increasing reactive oxygen species levels, which further supports the NQO-1 inhibitory activity. Furthermore, 4 compounds (compounds 5-7 and 10) were qualified by the Development Therapeutic Program (DTP) division of the National Cancer Institute (NCI) for full panel five-dose in vitro assay to determine their GI50 on the 60 cell lines. All five compounds showed broad spectrum sub-micromolar to single digit micromolar GI50 against a wide range of cell lines. Cell cycle analysis and dual staining assays with annexin V-FITC/propidium iodide on MCF-7 cells confirmed the capability of the most active compound (compound 5) to induce cell cycle arrest at Pre-G1 and G2/M phases as well as apoptosis. Both cell cycle arrest and apoptosis were affirmed at the molecular level by the ability of compound 5 to enhance the expression levels of caspase-3 and Bax together with suppressing that of CDK1 and Bcl-2. Additionally, an anti-angiogenic effect was evident with compound 5 as supported by the decreased expression of VEGF. Interesting binding modes within NQO-1 active site had been identified and confirmed by both molecular docking and dymanic experiments.

Discovery of potent thieno[2,3-d]pyrimidine VEGFR-2 inhibitors: Design, synthesis and enzyme inhibitory evaluation supported by molecular dynamics simulations.

Vascular endothelial growth factor receptor (VEGFR) is one of the well-known targets that control angiogenesis and cancer progression. In this study, we are reporting the design, synthesis and biological evaluation of a series of 4-substituted thieno[2,3-d]pyrimidine derivatives as VEGFR-2 inhibitors. The design of these compounds was based on interactions extracted from crystal structure of potent pyrrolo[3,2-d]pyrimidine inhibitor VIII with VEGFR-2 (PDB: 3VHE). In addition to these interactions, the new compounds were also designed to interact with residues in the solvent accessible region such as Asn923. Accordingly, the thienopyrimidine target compounds were synthesized and subjected to VEGFR-2 enzyme inhibition assay. Several target compounds (7d-f, 8b-c, 8e-g and 15c) exhibited potent inhibitory activities against VEGFR-2 with IC50 values in low nanomolar range. Compounds 8b and 8e revealed exceptionally potent inhibitory activity with IC50 of 5 and 3.9 nM, respectively. The molecular docking analysis and molecular dynamics simulation were also performed to further investigate these findings.