Molecular docking study and antiviral evaluation of 2-thioxo-benzo[g]quinazolin-4(3H)-one derivatives

Benzo[g]quinazolines as antifungal against candidiasis: Screening, molecular docking, and QSAR investigations

Candida albicans, an opportunistic pathogen, is the most common type of fungus and represents a substantial source of human invasive disease (nosocomial infection). This category of fungi are part of our microbiota, and given the appropriate environmental conditions, it has the potential to cause both superficial and systemic infections. There is a soaring resistance against the available anticandidal agents. The purpose of this research is to investigate the activity of certain previously synthesized benzo[g]quinazolines against C. albicans in vitro by using the cup-plate diffusion method. There was a marked difference in the effectiveness of the target compounds 1-6 against the sample of C. albicans that was tested. Benzo[g]quinazolines 1 (inhibition zone = 20 mm) and 2 (inhibition zone = 22 mm) had good effects in comparison to fluconazole (inhibition zone = 26 mm). A docking study was conducted between benzo[g]quinazolines 1-6 and Candida spp. CYP51 to establish the binding mode compared with fluconazole and VT-1161 (oteseconazole) as reference medicines, and it was determined that binding at the active site of Candida spp. CYP51 occurred in the same manner. Quantitative structure-activity relationship (QSAR) investigation was performed to further characterize the identified anticandidal agents and recognize the major regulatory components governing such activity. In future studies, the benzo[g]quinazoline scaffold could serve as a model for the design and development of novel derivatives with antifungal potential.

Biological Investigation of 2-Thioxo-benzo[g]quinazolines against Adenovirus Type 7 and Bacteriophage Phi X174: An In Vitro Study

Mortality and morbidity caused by viruses are a global health problems. Therefore, there is always a need to create novel therapeutic agents and refine existing ones to maximize their efficacy. Our lab has produced benzoquinazolines derivatives that have proven effective activity as antiviral compounds against herpes simplex (HSV 1 and 2), coxsackievirus B4 (CVB4), and hepatitis viruses (HAV and HCV). This in vitro study was aimed at investigating the effectiveness of benzoquinazoline derivatives 1-16 against adenovirus type 7 and bacteriophage phiX174 using a plaque assay. The cytotoxicity against adenovirus type 7 was also performed in vitro, using a MTT assay. Most of the compounds exhibited antiviral activity against bacteriophage phiX174. However, compounds 1, 3, 9, and 11 showed statistically significant reductions of 60-70% against bacteriophage phiX174. By contrast, compounds 3, 5, 7, 12, 13, and 15 were ineffective against adenovirus type 7, and compounds 6 and 16 had remarkable efficacy (50%). Using the MOE-Site Finder Module, a docking study was carried out in order to create a prediction regarding the orientation of the lead compounds (1, 9, and 11). This was performed in order to investigate the activity of the lead compounds 1, 9, and 11 against the bacteriophage phiX174 by locating the ligand-target protein binding interaction active sites.

Evaluation of Some Benzo[g]Quinazoline Derivatives as Antiviral Agents against Human Rotavirus Wa Strain: Biological Screening and Docking Study

Globally, rotavirus (RV) is the most common cause of acute gastroenteritis in infants and toddlers; however, there are currently no agents available that are tailored to treat rotavirus infection in particular. Improved and widespread immunization programs are being implemented worldwide to reduce rotavirus morbidity and mortality. Despite certain immunizations, there are no licensed antivirals that can attack rotavirus in hosts. Benzoquinazolines, chemical components synthesized in our laboratory, were developed as antiviral agents, and showed good activity against herpes simplex, coxsackievirus B4 and hepatitis A and C. In this research project, an in vitro investigation of the effectiveness of benzoquinazoline derivatives 1–16 against human rotavirus Wa strains was carried out. All compounds exhibited antiviral activity, however compounds 1–3, 9 and 16 showed the greatest activity (reduction percentages ranged from 50 to 66%). In-silico molecular docking of highly active compounds, which were selected after studying the biological activity of all investigated of benzo[g]quinazolines compounds, was implemented into the protein’s putative binding site to establish an optimal orientation for binding. As a result, compounds 1, 3, 9, and 16 are promising anti-rotavirus Wa strains that lead with Outer Capsid protein VP4 inhibition.

A Systematic Review of Second-Line Treatments in Antiviral Resistant Strains of HSV-1, HSV-2, and VZV

Drug-resistant variants of herpes simplex viruses (HSV) have been reported that are not effectively treated with first-line antiviral agents. The objective of this study was to evaluate available literature on the possible efficacy of second-line treatments in HSV and the use of second-line treatments in HSV strains that are resistant to first-line treatments. Following Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines, a final search was conducted in six databases on November 5, 2021 for all relevant literature using terms related to antiviral resistance, herpes, and HSV. Eligible manuscripts were required to report the presence of an existing or proposed second-line treatment for HSV-1, HSV-2, or varicella zoster virus (VZV); have full-text English-language access; and potentially reduce the rate of antiviral resistance. Following screening, 137 articles were included in qualitative synthesis. Of the included studies, articles that examined the relationship between viral resistance to first-line treatments and potential second-line treatments in HSV were included. The Cochrane risk-of-bias tool for randomized trials was used to assess risk of bias. Due to the heterogeneity of study designs, a meta-analysis of the studies was not performed. The dates in which accepted studies were published spanned from 2015-2021. In terms of sample characteristics, the majority (72.26%) of studies used Vero cells. When looking at the viruses on which the interventions were tested, the majority (84.67%) used HSV-1, with (34.31%) of these studies reporting testing on resistant HSV strains. Regarding the effectiveness of the proposed interventions, 91.97% were effective as potential managements for resistant strains of HSV. Of the papers reviewed, nectin in 2.19% of the reviews had efficacy as a second-line treatments in HSV, amenamevir in 2.19%, methanol extract in 2.19%, monoclonal antibodies in 1.46%, arbidol in 1.46%, siRNA swarms in 1.46%, Cucumis melo sulfated pectin in 1.46%, and components from Olea europeae in 1.46%. In addition to this griffithsin in 1.46% was effective, Morus alba L. in 1.46%, using nucleosides in 1.46%, botryosphaeran in 1.46%, monoterpenes in 1.46%, almond skin extracts in 1.46%, bortezomib in 1.46%, flavonoid compounds in 1.46%, andessential oils were effective in 1.46%, but not effective in 0.73%. The available literature reviewed consistently supports the existence and potentiality of second-line treatments for HSV strains that are resistant to first-line treatments. Immunocompromised patients have been noted to be the population most often affected by drug-resistant variants of HSV. Subsequently, we found that HSV infections in this patient population are challenging to manage clinically effectively. The goal of this systematic review is to provide additional information to patients on the potentiality of second-line treatment in HSV strains resistant to first-line treatments, especially those who are immunocompromised. All patients, whether they are immunocompromised or not, deserve to have their infections clinically managed in a manner supported by comprehensive research. This review provides necessary information about treatment options for patients with resistant HSV infections and their providers.

Significant pharmacological activities of benzoquinazolines scaffold

Benzoquinazolines, the essential constituents of numerous well-known heterocyclic systems, have occupied a prominent position and played a significant part in the synthesis of various pharmaceutical compounds. The wide range of pharmacological effects attributed to benzoquinazolines has been the subject of extensive study. These include their roles as anticancer, antimicrobial, anti-monoamine oxidase, anticonvulsant, antiviral, antinociceptive, antioxidant, antineoplastic, antituberculosis, antiplatelet, and antiphlogistic agents. This work provides an attempt at a literature review of the pharmacological activities of benzoquinazoline derivatives, including an up-to-date account of recent research findings, and suggests avenues for future exploration in the pursuit of more potent and specific analogues for a wide range of biological targets using this platform.

Synthesis and In Silico Investigation of Isatin-Based Schiff Bases as Potential Inhibitors for Promising Targets against SARS-CoV-2

Despite the significant development in vaccines and therapeutics cocktails, there is no specific treatment available for coronavirus disease 2019 (COVID-19), caused by the new severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). Targeting the main protease (M^pro) of SARS-CoV-2, which possesses a key role in producing the essential viral structural and functional proteins, can be considered an efficient way to control this potentially lethal infection. Recently, some of Michael acceptor-pharmacophore containing inhibitors have been suggested as successful suppressors of the main protease. Here, we synthesized the Isatin-based Schiff bases possessing the structural pattern of a Michael acceptor-like portion employing synthesis procedures. In silico investigation of these compounds was not limited to the main protease. We have also evaluated their possible inhibitory activity against the other identified druggable targets using homology modeling, molecular docking, and molecular dynamics simulations. Our investigations revealed that the dimethyl biguanide carrying Schiff bases of Isatin-derivatives have the best binding mode and interaction energy. The dimethyl biguanide moiety-containing compounds have formed promising interactions with the key amino acid residues Cys145 and HIS41 of M^pro with a binding free energy of -7.6 kcal/mol which was lower than the positive control compound Carmofur (-6.3 kcal/mol). It also leads to the higher affinity and the much inhibitory potential against the SARS-CoV-2 RdRp and Spike glycoproteins, human TMPRSS2, and ACE2 receptors.

Synthesis, crystal structure, DFT and molecular docking studies of N-acetyl-2,4-[diaryl-3-azabicyclo[3.3.1]nonan-9-yl]-9-spiro-4'-acetyl-2'-(acetylamino)-4',9-dihydro-[1',3',4']-thiadiazoles: A potential SARS-nCoV-2 Mpro (COVID-19) inhibitor

In this paper, we describe the synthesis and crystal structure analysis of N-acetyl-2,4-[diphenyl-3-azabicyclo[3.3.1]nonan-9-yl]-9-spiro-4′-acetyl-2′-(acetylamino)-4′,9-dihydro-[1′,3′,4′]-thiadiazole (3a) and N-acetyl- 2,4-[bis(p-methoxyphenyl)-3-azabicyclo[3.3.1]nonan-9-yl]-9-spiro-4′-acetyl-2′-(acetylamino)-4′,9-dihydro-[1′,3′,4′]-thiadiazole (3b). The title compounds 3a and 3b are characterized by 1D NMR and single crystal x-ray diffraction analysis. Non-covalent interactions in a molecule were identified by Hirshfeld surface (d_norm contacts and 2D fingerprint plot) analysis. In addition, the existence of chalcogen bond (S•••O bond) in the molecular structures (3a and 3b) are described by NCI-RDG and QTAIM analysis. NBO analysis is employed to describe the orbital interactions and electron transfer between sulfur and oxygen atoms. Molecular docking is carried out for compounds 3a and 3b with COVID-19 viral protein SARS-nCoV-2 M^pro (PDB ID: 6LU7).

Antiproliferative Activity of a New Quinazolin-4(3H)-One Derivative via Targeting Aurora Kinase A in Non-Small Cell Lung Cancer

Non-small cell lung cancer (NSCLC) is the most common lung cancer subtype. Although chemotherapy and targeted therapy are used for the treatment of patients with NSCLC, the survival rate remains very low. Recent findings suggested that aurora kinase A (AKA), a cell cycle regulator, is a potential target for NSCLC therapy. Previously, we reported that a chemical entity of quinazolin-4(3H)-one represents a new template for AKA inhibitors, with antiproliferative activity against cancer cells. A quinazolin-4(3H)-one derivative was further designed and synthesized in order to improve the pharmacokinetic properties and antiproliferation activity against NSCLC cell lines. The derivative, BIQO-19 (Ethyl 6-(4-oxo-3-(pyrimidin-2-ylmethyl)-3,4-dihydroquinazolin-6-yl)imidazo [1,2-a]pyridine-2-carboxylate), exhibited improved solubility and antiproliferative activity in NSCLC cells, including epidermal growth factor receptor–tyrosine kinase inhibitor (EGFR-TKI)-resistant NSCLC cells. BIQO-19 effectively inhibited the growth of the EGFR-TKI-resistant H1975 NSCLC cells, with the suppression of activated AKA (p-AKA) expression in these cells. The inhibition of AKA by BIQO-19 significantly induced G₂/M phase arrest and subsequently evoked apoptosis in H1975 cells. In addition, the combination of gefitinib and BIQO-19 exhibited synergistic antiproliferative activity in NSCLC cells. These findings suggest the potential of BIQO-19 as a novel therapeutic agent for restoring the sensitivity of gefitinib in EGFR-TKI-resistant NSCLC cells.

An overview of triazoloquinazolines: Pharmacological significance and recent developments

Nitrogen heterocyclic rings have participated to constitute most of the drugs and several pharmacologically related compounds. The existence of such hetero atoms/groups in heterocyclic systems privileged specificities in their biological objectives. Particularly, quinazoline and triazole are biologically imperative platforms known to be linked with various pharmacological activities. Some of the prominent pharmacological responses ascribed to these systems are analgesic, antiinflammatory, anticonvulsant, hypnotic, antihistaminic, antihypertensive, anticancer, antimicrobial, antitubercular, antiviral and antimalarial activities. This diversity in the pharmacological outputs for both triazole and quinazoline systems has encouraged the medicinal chemistry researchers to create several chemical routes aiming at the incorporation of two rings in one molecule named triazoloquinazoline system. This system has shown multiple potential activities against numerous targets. Correlation the specific structural features of triazoloquinazoline system with its pharmacological purposes has successively been achieved by performing several pharmacological examinations and structure-activity relationship studies. The development of triazoloquinazoline derivatives and the understanding of their pharmacological targets offer opportunities for novel therapeutics. This review mainly emphases on the medicinal chemistry aspects of triazoloquinazolines including synthesis, reactivity, biological activity and structure activity relationship studies (SARs). Moreover, this review collates literature reported by researchers on triazoquinazolines and provides detailed attention on their analogs pharmacological activities in the perspective of drug development and discovery.

Synthesis, Molecular Docking, biological potentials, and Structure-Activity Relationship of new quinazoline & quinazoline-4-one derivatives

CONTEXT

Quinazolines are a common class of nitrogen-containing heterocyclic scaffolds exhibiting a broad spectrum of pharmacological activities.

OBJECTIVE

In the present study, quinazoline and quinazolin-4-one derivatives were prepared, characterized to evaluate their biological which may pave the way for possible therapeutic applications.

MATERIALS & METHODS

A new derivative of quinazoline and quinazolin-4-one derivatives was prepared and tested for antiulcerogenic, anti-inflammatory and hepatoprotective activity.

RESULTS

The synthesized compounds were characterized by elemental analysis and spectral data. Also, the median lethal doses (LD_50s) of compounds 1-3 in rats were 1125, 835 and 1785 mg/kg b.w., respectively. IC₅₀ values of compounds (1-3) as measured by ABTS⁺ radical method was 0.8, 0.92 and 0.08 mg/mL, respectively. Antiulcerogenic activities at dose 1/20 LD₅₀ in albino rats were 47.94, 24.60 and 56.45%, respectively. Anti-inflammatory effect at dose 1/20 LD₅₀ of compounds (1-3) induced edema model after 120 min. The prepared compounds possess hepato gastric mucosa protective activity against ibuprofen-induced ulceration and LPS-induced liver toxicity, respectively in rats via normalization of oxidative stress biomarkers and inflammatory mediators were inhibited in peritoneal macrophage cells at concentration of 100 µg/L. Molecular docking suggested that the most active compounds 1 and 2 can be positioned within the active sites of COX-2 at Arg121 & Tyr356 similar to ibuprofen (Arg-120, Glu-524, and Tyr-355). The compound 3-COX-2 complex generated by docking revealed intricate interactions with a COX-2 channel.

CONCLUSION

These findings suggest that compounds 1-3 exhibited good antioxidant, antiulcer, anti-inflammatory activity and safe on liver enzymes in rats.

Antiproliferative and Antiangiogenic Properties of New VEGFR-2-targeting 2-thioxobenzo[g]quinazoline Derivatives (In Vitro)

A series of 3-ethyl(methyl)-2-thioxo-2,3-dihydrobenzo[g]quinazolines (1-17) were synthesized, characterized, and evaluated in vitro for their antiangiogenesis VEGFR-2-targeting, antiproliferative, and antiapoptotic activities against breast MCF-7 and liver HepG2 cells. Flow cytometry was used to determine cancer-cell cycle distributions, and apoptosis was detected using annexin-V-FITC (V) and propidium iodide (PI) dyes. Fluorescence microscopy, in combination with Hoechst staining was used to detect DNA fragmentation. Most of the tested benzo[g]quinazolines demonstrated promising activity (IC50 = 8.8 ± 0.5-10.9 ± 0.9 μM) and (IC50 = 26.0 ± 2.5-40.4 ± 4.1 μM) against MCF-7 and HepG2, respectively. Doxorubicin was used as a reference drug. Compounds 13-15 showed the highest activity against both cancer cell lines. Differential effects were detected by cell-cycle analysis, indicating similarities in the actions of 13 and 14 against both MCF7 and HepG2, involving the targeting of G1 and S phases, respectively. Compound 15 showed similar indices against both cells, indicating that its cytotoxicity toward the examined cancer cells could be unselective. Interestingly, 14 and 15 showed the highest apoptosis (30.76% and 25.30%, respectively) against MCF-7. The DNA fragmentation results agreed well with the apoptosis detected by flow cytometry. In terms of antiangiogenesis activity, as derived from VEGFR-2 inhibition, 13 and 15 were comparable to sorafenib and effected 1.5- and 1.4-fold inhibition relative to the standard sorafenib. A docking study was conducted to investigate the interaction between the synthesized benzo[g]quinazolines and the ATP-binding site within the catalytic domain of VEGFR-2.

Synthesis and biofilm inhibition studies of 2-(2-amino-6-arylpyrimidin-4-yl)quinazolin-4(3H)-ones

Synthesis of novel 4(3H)-quinazolinonyl aminopyrimidine derivatives has been achieved via quinazolinonyl enones which in turn were obtained from 2-acyl-4(3H)-quinazolinone. They have been assayed for biofilm inhibition against Gram-positive (methicillin-resistant Staphylococcus aureus (MRSA)) and Gram-negative bacteria (Acinetobacter baumannii). The analogues with 2,4,6-trimethoxy phenyl, 4-methylthio phenyl, and 3-bromo phenyl substituents (5h, 5j & 5k) have been shown to inhibit biofilm formation efficiently in MRSA with IC50 values of 20.7-22.4 μM). The analogues 5h and 5j have demonstrated low toxicity in human cells in vitro and can be investigated further as leads.

Investigation of some benzoquinazoline and quinazoline derivatives as novel inhibitors of HCV-NS3/4A protease: biological, molecular docking and QSAR studies

Morbidity and mortality due to hepatitis C virus (HCV) is a globe health concern. Hence, there is a persistent demand to design and optimize current HCV therapy and develop novel agents. HCV NS3/A4 protease plays an essential role in HCV life cycle and replication. Thus, HCV NS3/A4 protease inhibitors are one of the best therapeutic targets for the identification of novel candidate drugs. Recent studies have shown some benzoquinazolines as potent antiviral agents and promising HAV-3C protease inhibitors. In the present study, a series of benzo[g]quinazolines (1–13) and their quinazoline analogues (14–17) were evaluated for their HCV-NS3/4A inhibitory activities using in vitro assay. Our results revealed that the target compounds inhibited the activity of the NS3/4A enzyme, (IC₅₀ = 6.41 ± 0.12 to 78.80 ± 1.70 μM) in comparison to telaprevir (IC₅₀ = 1.72 ± 0.03 μM) as a reference drug. Compounds 1, 2, 3, 9, 10 and 13 showed the highest activity (IC₅₀ = 11.02 ± 0.25, 6.41 ± 0.12, 9.35 ± 0.19, 9.08 ± 0.20, 16.03 ± 0.34 and 7.21 ± 0.15 μM, respectively). Molecular docking was performed to study the binding modes of the docked-chosen benzo[g]quinazolines, hydrogen bonding, and amino acid residues at the catalytic triad of the NS3/4A enzyme of HCV. The QSAR was determined to explore the relationships between the molecular structures of the targets and their biological activities by developing prediction models among the known HCV NS3/A4 inhibitors and then to predict the inhibitory activity of the target molecules synthesized.

HCV NS3/A4 protease inhibitors are one of the best therapeutic targets for the identification of novel candidate drugs. A series of benzo[g]quinazolines and their quinazoline analogues were evaluated for their HCV-NS3/4A inhibitory activities.

Synthesis, characterization and computational study on potential inhibitory action of novel azo imidazole derivatives against COVID-19 main protease (Mpro: 6LU7)

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Six azo imidazole derivatives have been synthesized and characterized by spectroscopic and analytical tools.

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Inhibitory potential against main protease (6LU7) have been investigated using computational techniques.

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Binding energy of the ligands has found in the range −6.7 Kcal/mole to −8.1 Kcal/mole.

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The order of the ligands towards the protein 6LU7 are L5> L4≈L6>L1>L2>L3.

A series of six novel imidazole anchored azo-imidazole derivatives (L1-L6) have been prepared by the simple condensation reaction of azo-coupled ortho-vaniline precursor with amino functionalised imidazole derivative and the synthesized derivatives (L1-L6) have been characterized by different analytical and spectroscopic techniques. Molecular docking studies were carried out to ascertain the inhibitory action of studied ligands (L1-L6) against the Main Protease (6LU7) of novel coronavirus (COVID-19). The result of the docking of L1-L6 showed a significant inhibitory action against the Main protease (M^pro) of SARS-CoV-2 and the binding energy (ΔG) values of the ligands (L1-L6) against the protein 6LU7 have found to be -7.7 Kcal/mole (L1), -7.4 Kcal/mole (L2), -6.7 Kcal/mole (L3), -7.9 Kcal/mole (L4), -8.1 Kcal/mole (L5) and -7.9 Kcal/mole (L6). Pharmacokinetic properties (ADME) of the ligands (L1-L6) have also been studied.

Anti-HAV evaluation and molecular docking of newly synthesized 3-benzyl(phenethyl)benzo[g]quinazolines

Synthesized 3-benzyl(phenethyl)benzo[g]quinazolines (1-17) were evaluated in vitro to determine their effects against the anti-hepatitis A virus (HAV) using a cytopathic effect inhibition assay. Of the synthesized compounds, 16 and 17 showed considerably high anti-HAV activity, as indicated by their EC₅₀ values of 27.59 and 18 μM, respectively, when compared to that of amantadine (37.3 μM), the standard therapeutic agent. In addition, they exhibited low cytotoxicity as indicated by their CC₅₀ values, 290.63 and 569.45 μM, respectively. Compounds 1, 2, and 5 exhibited remarkable activity compared to the active compounds (16, 17) and amantadine. The selectivity index (SI) values were calculated and applied as a parameter for classifying the activity of the targets. In addition, molecular docking was performed to rationalize the SAR of the target compounds and analyze the binding modes between the docked-selected compounds and amino acid residues in the active site of the HAV-3C proteinase enzyme.

Antioxidant activities and molecular docking of 2-thioxobenzo[g]quinazoline derivatives

BACKGROUND

Oxidative stress and related diseases resulting from the overproduction of free radicals can be counteracted by designing and developing novel antioxidative agents that can protect the human body against the damage caused by free radicals.

METHODS

The present study evaluated the antioxidant activities of 15 derivatives of 2-thioxobenzo[g]quinazoline using three different assays: 1,1-diphenyl-2-picryl hydrazyl (DPPH) radical scavenging, reducing power capability, and ferric reduction antioxidant power.

RESULTS

Some benzoquinazolines had good activity and had the capacity to deplete DPPH and free radicals compared to a positive control butylated hydroxyl toluene (BHT). A docking study identified the possible interactions between binding models and the antioxidant activities of the target compounds.

CONCLUSIONS

The active compounds can be used as templates for further development of more potent antioxidative agents.

Synthesis, biological activity and molecular docking of new tricyclic series as α-glucosidase inhibitors

Diabetes is an emerging metabolic disorder. α-Glucosidase inhibitors, such as acarbose, delay the hydrolysis of carbohydrates by interfering with the digestive enzymes. This action decreases the glucose absorption and the postprandial glucose level. We have synthesized 25 tricyclic 2-phenoxypyrido[3,2-e][1,2,4]triazolo[1,5-a]pyrimidin-5(4H)-ones hybrids and evaluated their α-glucosidase inhibitory activity. Compounds 6h and 6d have shown stronger activity than that of acarbose. Compound 6h exhibited the highest inhibition with an IC₅₀ of 104.07 µM. Molecular modelling studies revealed that compound 6h inhibits α-glucosidase due to the formation of a stable ligand-α-glucosidase complex and extra hydrogen bond interactions, and directed in the binding site by Trp329.

Radioiodination and biodistribution of newly synthesized 3-benzyl-2-([3-methoxybenzyl]thio)benzo[g]quinazolin-4-(3H)-one in tumor bearing mice

3-Benzyl-2-((3-methoxybenzyl)thio)benzo[g]quinazolin-4(3H)-one was previously synthesized and proved by physicochemical analyses (HRMS, 1H and 13C NMR). The target compound was examined for its radioactivity and the results showed that benzo[g]quinazoline was successfully labeled with radioactive iodine using NBS via an electrophilic substitution reaction. The reaction parameters that affected the labeling yield such as concentration, pH and time were studied to optimize the labeling conditions. The radiochemical yield was 91.2 ± 1.22% and the in vitro studies showed that the target compound was stable for up to 24 h. The thyroid was among the other organs in which the uptake of 125I-benzoquinazoline has increased significantly over the time up to 4.1%. The tumor uptake was 6.95%. Radiochemical and metabolic stability of the benzoquinazoline in vivo/in vitro and biodistribution studies provide some insights about the requirements for developing more potent radiopharmaceutical for targeting the tumor cells.

Berberine-piperazine conjugates as potent influenza neuraminidase blocker

In these studies, we analyzed substituted piperazine based berberine analogs conjugated through a pentyloxy side chain for their in vitro and in silico biological effects. All the final analogs were screened for their in vitro antiviral action against a collection of different influenza virus strains using the CPE assay and SRB assay. Moreover, their cytotoxicity towards non-cancer cell lines was examined employing Madin-Darby canine kidney (MDCK) cell lines. The anti-influenza activities of berberine-piperazine derivatives (BPD) were evaluated in the range from 35.16 μg/mL to 90.25 μg/mL of the IC₅₀s along with cytotoxicity level which was observed in the range 44.8 μg/mL to 3890.6 μg/mL of CC₅₀s towards MDCK cells. In an effort to know the mechanism of action of BPD1-BPD23, results of Neuraminidase inhibition assay and Molecular docking studies carried out against neuraminidase as the target enzyme revealed that titled compounds are potential neuraminidase inhibitors that merge to the active site of neuraminidase, with moderate to high binding energy.

3-Benzyl(phenethyl)-2-thioxobenzo[g]quinazolines as a new class of potent α-glucosidase inhibitors: synthesis and molecular docking study

Aim: Using a simple modification on a previously reported synthetic route, 3-benzyl(phenethyl)-2-thioxobenzo[g]quinazolin-4(3H)-ones (1 and 2) were synthesized with high yields. Further transformation of 1 and 2 produced derivatives 3-26, which were structurally characterized based on NMR and MS data, and their in vitro α-glucosidase inhibitory activity was evaluated using Baker's yeast α-glucosidase enzyme. Results: Compounds 2, 4, 8, 12 and 20 exhibited the highest activity (IC50 = 69.20, 59.60, 49.40, 50.20 and 83.20 μM, respectively) compared with the standard acarbose (IC50 = 143.54 μM). Conclusion: A new class of potent α-glucosidase inhibitors was identified, and the molecular docking predicted plausible binding interaction of the targets in the binding pocket of α-glucosidase and rationalized the structure–activity relationship (SARs) of the target compounds.

Quantum Chemical Calculations and Statistical Analysis: Structural Cytotoxicity Relationships of some Synthesized 2-thiophen-naphtho(benzo)oxazinone Derivatives

Twenty-two 2-thiophen-naphtho(benzo)oxazinone derivatives are prepared using 3-amino-2-naphthoic and 5-nitroanthranilic acids as building blocks. The target compounds (1-22) were evaluated quantitatively for their cytotoxic effects in vitro against three cancer cell lines, including the lung A549, the hepatocyte HepG2, and the breast MCF-7 carcinoma cells. Compounds 1, 12, 14, and 21 were found to exhibit remarkable cytotoxicity against the tested cancer cell lines. Compound 21 has shown the highest activity against A549 and MCF-7 (IC₅₀: 9.8 & 3.6 µg mL^-1) whereas 1 (IC₅₀: 5.9 µg mL^-1) and 5 (3.6 µg mL^-1) were the most active against HepG2. To elucidate the structure-cytotoxicity relationships of the synthesized compounds, a number of their chemical descriptors are determined including electronic, steric and hydrophobicity descriptors. The electronic properties were calculated through density functional theory (DFT) calculations at the B3LYP/6-31 + G(d,p). The impact of the chosen descriptors is evaluated statistically through simple and multiple linear regression analyses (SLR and MLR). SLR analyses reveal that the impact of each descriptor on the cell lines are relatively weak except for MCF-7, where hardness and softness show moderate correlations with correlation coefficients higher than 60%. The correlations were improved by considering MLR analyses (R² ≥ 90%), which showed that the cytotoxicity of synthesized compounds is correlated with their combined descriptors hardness, softness, electrophiliciy and hydrophobicity (LogP).

Discovery of berberine based derivatives as anti-influenza agent through blocking of neuraminidase

In this study, we investigated the antiviral activity of newly synthesized berberine derivatives (BD) against influenza virus infection using several strains in in vitro and in silico. The CPE reduction, pre-incubation, NA activity inhibition and molecular docking assays were used for antiviral evaluation. The anti-influenza activities of BDs were stronger than plant-derived pure commercial berberine, and some of the BDs were more potent than control drug Oseltamivir. The cytotoxicity level was observed in the range 63.16-1639μg/mL for synthesized BDs. Additionally, BDs were detected as able to block influenza viral particles. We targeted neuraminidase one of the influenza surface protein for further probing. Moreover, BDs registered competitive NA inhibition activity comparing with Oseltamivir. The active site of viral NA subunit was fully blocked by BD as the same location as Oseltamivir. The binding energies between influenza NA subunit and BD-5 were higher than Oseltamivir. More H-bonds and NA residues were occupied by BD for stronger binding ability than Oseltamivir. These results indicated that BD inhibits various strains of influenza virus by blocking of viral NA subunit.