A Review of FDA-Approved Anti-HIV-1 Drugs, Anti-Gag Compounds, and Potential Strategies for HIV-1 Eradication

Acquired immunodeficiency syndrome (AIDS) is an enormous global health threat stemming from human immunodeficiency virus (HIV-1) infection. Up to now, the tremendous advances in combination antiretroviral therapy (cART) have shifted HIV-1 infection from a fatal illness into a manageable chronic disorder. However, the presence of latent reservoirs, the multifaceted nature of HIV-1, drug resistance, severe off-target effects, poor adherence, and high cost restrict the efficacy of current cART targeting the distinct stages of the virus life cycle. Therefore, there is an unmet need for the discovery of new therapeutics that not only bypass the limitations of the current therapy but also protect the body's health at the same time. The main goal for complete HIV-1 eradication is purging latently infected cells from patients' bodies. A potential strategy called "lock-in and apoptosis" targets the budding phase of the life cycle of the virus and leads to susceptibility to apoptosis of HIV-1 infected cells for the elimination of HIV-1 reservoirs and, ultimately, for complete eradication. The current work intends to present the main advantages and disadvantages of United States Food and Drug Administration (FDA)-approved anti-HIV-1 drugs as well as plausible strategies for the design and development of more anti-HIV-1 compounds with better potency, favorable pharmacokinetic profiles, and improved safety issues.

Scaffold Hopping and Structural Modification of NSC 663284: Discovery of Potent (Non)Halogenated Aminobenzoquinones

The development of new anticancer drugs is still ongoing as a solution to the unsatisfactory results obtained by chemotherapy patients. Our previous studies on natural product-based anticancer agents led us to synthesize a new series of Plastoquinone (PQ) analogs and study their anticancer effects. Four members of PQ analogs (PQ1-4) were designed based on the scaffold hopping strategy; the design was later completed with structural modification. The obtained PQ analogs were synthesized and biologically evaluated against different cancer genotypes according to NCI-60 screening in vitro. According to the NCI results, bromo and iodo-substituted PQ analogs (PQ2 and PQ3) showed remarkable anticancer activities with a wide-spectrum profile. Among the two selected analogs (PQ2 and PQ3), PQ2 showed promising anticancer activity, in particular against leukemia cell lines, at both single- and five-dose NCI screenings. This compound was also detected by MTT assay to reveal significant selectivity between Jurkat cells and PBMC (healthy) compared to imatinib. Further in silico studies indicated that PQ2 was able to occupy the ATP-binding cleft of Abl TK, one of the main targets of leukemia, through key interactions similar to dasatinib and imatinib. PQ2 is also bound to the minor groove of the double helix of DNA. Based on computational pharmacokinetic studies, PQ2 possessed a remarkable drug-like profile, making it a potential anti-leukemia drug candidate for future studies.

Structural Characterization of TRAF6 N-Terminal for Therapeutic Uses and Computational Studies on New Derivatives

Tumor necrosis factor receptor-associated factors (TRAFs) are a protein family with a wide variety of roles and binding partners. Among them, TRAF6, a ubiquitin ligase, possesses unique receptor binding specificity and shows diverse functions in immune system regulation, cellular signaling, central nervous system, and tumor formation. TRAF6 consists of an N-terminal Really Interesting New Gene (RING) domain, multiple zinc fingers, and a C-terminal TRAF domain. TRAF6 is an important therapeutic target for various disorders and structural studies of this protein are crucial for the development of next-generation therapeutics. Here, we presented a TRAF6 N-terminal structure determined at the Turkish light source "Turkish DeLight" to be 3.2 Å resolution at cryogenic temperature (PDB ID: 8HZ2). This structure offers insight into the domain organization and zinc-binding, which are critical for protein function. Since the RING domain and the zinc fingers are key targets for TRAF6 therapeutics, structural insights are crucial for future research. Separately, we rationally designed numerous new compounds and performed molecular docking studies using this template (PDB ID:8HZ2). According to the results, 10 new compounds formed key interactions with essential residues and zinc ion in the N-terminal region of TRAF6. Molecular dynamic (MD) simulations were performed for 300 ns to evaluate the stability of three docked complexes (compounds 256, 322, and 489). Compounds 256 and 489 was found to possess favorable bindings with TRAF6. These new compounds also showed moderate to good pharmacokinetic profiles, making them potential future drug candidates as TRAF6 inhibitors.

Does detection of a large for gestational age (LGA) fetus in fetal anomaly scan (FAS) require an early oral glucose screening test (OGTT) and can LGA fetus be detected at birth?

OBJECTIVE

Gestational diabetes mellitus (GDM) complications increase with late diagnosis and late treatment, so early diagnosis and treatment is one of the most important factors in preventing complications. We tried to find an answer to the question of whether the detection of large for gestational age (LGA) fetus in fetal anomaly scan (FAS) requires earlier oral glucose screening test (OGTT) and predicts LGA fetus at birth.

PATIENTS AND METHODS

Pregnant women who underwent fetal anomaly scan and gestational diabetes screening at the Department of Obstetrics and Gynecology, University of Health Sciences, Tepecik Training and Research Hospital between 2018 and 2020 were included in this large retrospective cohort study. FAS was routinely performed between 18-22 weeks in our hospital. 75 grams of OGTT was used for gestational diabetes screening and it was performed between 24-28 weeks.

RESULTS

This large retrospective cohort study was performed on 3,180 fetuses, 2,904 appropriate for gestational age (AGA) and 276 LGA, in the second trimester. The prevalence of GDM was significantly higher in the LGA group (OR 2.44, 95% CI 1.66-3.58; p < 0.001). Insulin requirement for blood glucose regulation was significantly higher in the LGA group (OR 3.6, 95% CI 1.68-7.7; p = 0.001). Fasting and 1st hour OGTT values were similar between the groups, but 2nd hour OGTT values were significantly higher in the second trimester LGA group (p = 0.041). The prevalence of LGA newborns at birth was higher in second trimester LGA fetuses than in fetuses with AGA (21.1% vs. 7.1%, p < 0.001).

CONCLUSIONS

The fact that the estimated fetal weight (EFW) measured in the second trimester FAS is LGA may be related to GDM in the future and LGA fetus at birth. A more detailed GDM risk questioning should be performed to these mothers and OGTT should be considered when additional risk factors are detected. In addition to all these, glucose regulation may not be possible with diet alone in mothers who have LGA in the second trimester ultrasound and who may have GDM in the future. These mothers should be monitored more closely and more carefully.

Discovery of Small Molecule COX-1 and Akt Inhibitors as Anti-NSCLC Agents Endowed with Anti-Inflammatory Action

Targeted therapies have come into prominence in the ongoing battle against non-small cell lung cancer (NSCLC) because of the shortcomings of traditional chemotherapy. In this context, indole-based small molecules, which were synthesized efficiently, were subjected to an in vitro colorimetric assay to evaluate their cyclooxygenase (COX) inhibitory profiles. Compounds 3b and 4a were found to be the most selective COX-1 inhibitors in this series with IC₅₀ values of 8.90 µM and 10.00 µM, respectively. In vitro and in vivo assays were performed to evaluate their anti-NSCLC and anti-inflammatory action, respectively. 2-(1H-Indol-3-yl)-N'-(4-morpholinobenzylidene)acetohydrazide (3b) showed selective cytotoxic activity against A549 human lung adenocarcinoma cells through apoptosis induction and Akt inhibition. The in vivo experimental data revealed that compound 3b decreased the serum myeloperoxidase and nitric oxide levels, pointing out its anti-inflammatory action. Moreover, compound 3b diminished the serum aminotransferase (particularly aspartate aminotransferase) levels. Based on the in vitro and in vivo experimental data, compound 3b stands out as a lead anti-NSCLC agent endowed with in vivo anti-inflammatory action, acting as a dual COX-1 and Akt inhibitor.

An investigation of bacteriocin nisin anti-cancer effects and FZD7 protein interactions in liver cancer cells

The bacteriocin, nisin, produced by Lactococcus and Streptococcus species during fermentation, is widely used for bio preservatives in a wide variety of foods. Liver cancer has a high mortality rate and is the fourth leading cause of cancer-related deaths worldwide. Recently, researchers have shown the anti-cancer effects of nisin through in vitro and in vivo studies. This study aimed to investigate the effect of nisin on liver cancer cell lines, which represented two subgroups of the disease model. Nisin exhibited significant growth inhibition and apoptosis in both cell lines, HuH-7, and SNU182. Drug resistance is the main problem in liver cancer and the epithelial-to-mesenchymal transition has a role in the development of drug resistance in hepatocellular carcinoma. The expression of EMT transcription factors ZEB1, SNAI1, and TWIST1 were analyzed depending on nisin treatment, TWIST1 expression was down-regulated after nisin treatment compared to the untreated SNU182 and HuH-7 cell lines. Besides, due to the reported correlation between the overexpression of Frizzled (FZD) proteins, specifically FZD7, in primary hepatocellular carcinomas (HCCs), molecular docking was assessed for Nisin A in the binding site of FZD7. Results confirmed that Nisin A was able to form important hydrogen bonding with key residues. This research not only determined the role of nisin in different liver cancer cell models but it also provided the first result of FZD7 and nisin interaction.

Design, semi-synthesis and examination of new gypsogenin derivatives against leukemia via Abl tyrosine kinase inhibition and apoptosis induction

Chronic myelogenous leukemia (CML) is characterized by Philadelphia translocation arising from Bcr-Abl fusion gene, which encodes abnormal oncoprotein showing tyrosine kinase (TK) function. Certain mutations in kinase domain, off-target effects and resistance problems of current TK inhibitors require the discovery of novel Abl TK inhibitors. For this purpose, herein, we synthesized new gypsogenin derivatives (6a-l) and evaluated their anticancer effects towards CML cells along with healthy cell line and different leukemic cells. Among these compounds, compound 6l was found as the most active anti-leukemic agent against K562 CML cells compared to imatinib exerting less cytotoxicity towards PBMCs (healthy). This compound also revealed significant anti-leukemic effects against Jurkat cell line. Besides, compound 6l enhanced apoptosis in CML cells with 52.4 % when compared with imatinib (61.8 %) and inhibited Abl TK significantly with an IC₅₀ value of 13.04 ± 2.48 μM in a large panel of kinases accentuating Abl TK-mediated apoptosis of compound 6l in CML cells. Molecular docking outcomes showed that compound 6l formed mainly crucial interactions in the ATP-binding cleft of Abl TK similar to that of imatinib. Ultimately, in silico pharmacokinetic evaluation of compound 6l indicated that this compound was endowed with anti-leukemic drug candidate features.

A new series of thiosemicarbazone-based anti-inflammatory agents exerting their action through cyclooxygenase inhibition

In an endeavor to identify potent anti-inflammatory agents, new thiosemicarbazones (TSCs) incorporated into a diaryl ether framework (2a-2l) were prepared and screened for their in vitro inhibitory effects on cyclooxygenases (COXs). 4-[4-(Piperidin-1-ylsulfonyl)phenyl]-1-[4-(4-cyanophenoxy)benzylidene]thiosemicarbazide (2c) was the most potent and selective COX-1 inhibitor in this series, with an IC₅₀ value of 1.89 ± 0.04 µM. On the other hand, 4-[4-(piperidin-1-ylsulfonyl)phenyl]-1-[4-(4-nitrophenoxy)benzylidene]thiosemicarbazide (2b) was identified as a nonselective COX inhibitor (COX-1 IC₅₀  = 13.44 ± 0.65 µM, COX-2 IC₅₀  = 12.60 ± 0.78 µM). Based on molecular docking studies, the diaryl ether and the TSC groups serve as crucial moieties for interactions with pivotal amino acid residues in the active sites of COXs. According to MTT test, compounds 2b and 2c showed low cytotoxic activity toward NIH/3T3 cells. Their in vivo anti-inflammatory and antioxidant potencies were also assessed using the lipopolysaccharide-induced sepsis model. Compounds 2b and 2c diminished high-sensitivity C-reactive protein, myeloperoxidase, nitric oxide, and malondialdehyde levels. Both compounds also caused a significant decrease in aspartate aminotransferase levels as well as alanine aminotransferase levels. In silico pharmacokinetic studies suggest that compounds 2b and 2c possess favorable drug-likeness and oral bioavailability. It can be concluded that these compounds may act as orally bioavailable anti-inflammatory and antioxidant agents.

Comprehensive Research on Past and Future Therapeutic Strategies Devoted to Treatment of Amyotrophic Lateral Sclerosis

Amyotrophic lateral sclerosis (ALS) is a rapidly debilitating fatal neurodegenerative disorder, causing muscle atrophy and weakness, which leads to paralysis and eventual death. ALS has a multifaceted nature affected by many pathological mechanisms, including oxidative stress (also via protein aggregation), mitochondrial dysfunction, glutamate-induced excitotoxicity, apoptosis, neuroinflammation, axonal degeneration, skeletal muscle deterioration and viruses. This complexity is a major obstacle in defeating ALS. At present, riluzole and edaravone are the only drugs that have passed clinical trials for the treatment of ALS, notwithstanding that they showed modest benefits in a limited population of ALS. A dextromethorphan hydrobromide and quinidine sulfate combination was also approved to treat pseudobulbar affect (PBA) in the course of ALS. Globally, there is a struggle to prevent or alleviate the symptoms of this neurodegenerative disease, including implementation of antisense oligonucleotides (ASOs), induced pluripotent stem cells (iPSCs), CRISPR-9/Cas technique, non-invasive brain stimulation (NIBS) or ALS-on-a-chip technology. Additionally, researchers have synthesized and screened new compounds to be effective in ALS beyond the drug repurposing strategy. Despite all these efforts, ALS treatment is largely limited to palliative care, and there is a strong need for new therapeutics to be developed. This review focuses on and discusses which therapeutic strategies have been followed so far and what can be done in the future for the treatment of ALS.

A New Series of Indeno[1,2-c]pyrazoles as EGFR TK Inhibitors for NSCLC Therapy

Non-small cell lung cancer (NSCLC) is the leading cause of cancer-related death throughout the world. Due to the shortcomings of traditional chemotherapy, targeted therapies have come into prominence for the management of NSCLC. In particular, epidermal growth factor receptor (EGFR) tyrosine kinase inhibitor (TKI) therapy has emerged as a first-line therapy for NSCLC patients with EGFR-activating mutations. In this context, new indenopyrazoles, which were prepared by an efficient microwave-assisted method, were subjected to in silico and in vitro assays to evaluate their potency as EGFR TK-targeted anti-NSCLC agents. Compound 4 was the most promising antitumor agent towards A549 human lung adenocarcinoma cells, with an IC₅₀ value of 6.13 µM compared to erlotinib (IC₅₀ = 19.67 µM). Based on its low cytotoxicity to peripheral blood mononuclear cells (PBMCs), it can be concluded that compound 4 exerts selective antitumor action. This compound also inhibited EGFR TK with an IC₅₀ value of 17.58 µM compared to erlotinib (IC₅₀ = 0.04 µM) and induced apoptosis (56.30%). Taking into account in silico and in vitro data, compound 4 stands out as a potential EGFR TKI for the treatment of NSCLC.

Novel metabolic enzyme inhibitors designed through the molecular hybridization of thiazole and pyrazoline scaffolds

New hybrid thiazolyl-pyrazoline derivatives (4a-k) were obtained through a facile and versatile synthetic procedure, and their inhibitory effects on the human carbonic anhydrase (hCA) isoforms I and II as well as on acetylcholinesterase (AChE) were determined. All new thiazolyl-pyrazolines showed activity at nanomolar levels as hCA I, hCA II, and AChE inhibitors, with K_I values in the range of 13.35-63.79, 7.01-115.80, and 17.89-48.05 nM, respectively. 1-[4-(4-Cyanophenyl)thiazol-2-yl]-3-(4-piperidinophenyl)-5-(4-fluorophenyl)-2-pyrazoline (4f) and 1-(4-phenylthiazol-2-yl)-3-(4-piperidinophenyl)-5-(4-fluorophenyl)-2-pyrazoline (4a) against hCAs and 1-[4-(4-chlorophenyl)thiazol-2-yl]-3-(4-piperidinophenyl)-5-(4-fluorophenyl)-2-pyrazoline (4d) and 1-[4-(4-nitrophenyl)thiazol-2-yl]-3-(4-piperidinophenyl)-5-(4-fluorophenyl)-2-pyrazoline (4b) against AChE were identified as highly potent inhibitors, superior to the standard drugs, acetazolamide and tacrine, respectively. Compounds 4a-k were also evaluated for their cytotoxic effects on the L929 mouse fibroblast (normal) cell line. Moreover, a comprehensive ligand-receptor interaction prediction was performed using the ADME-Tox, Glide XP, and MM-GBSA modules of the Schrödinger Small-Molecule Drug Discovery Suite to elucidate the potential binding modes of the new hybrid inhibitors against these metabolic enzymes.

Design, synthesis and investigation of the mechanism of action underlying anti-leukemic effects of the quinolinequinones as LY83583 analogs

Literature conclusively shows that one of the quinolinequinone analogs (6-anilino-5,8-quinolinequinone), referred to as LY83583 hereafter, an inhibitor of guanylyl cyclase, was used as the inhibitor of the cell proliferation in cancer cells. In the present work, a series of analogs of the LY83583 containing alkoxy group(s) in aminophenyl ring (AQQ1-15) were designed and synthesized via a two-step route and evaluated for their in vitro cytotoxic activity against four different cancer cell lines (K562, Jurkat, MT-2, and HeLa) and human peripheral blood mononuclear cells (PBMCs) by MTT assay. The analog (AQQ13) was identified to possess the most potent cytotoxic activity against K562 human chronic myelogenous (CML) cell line (IC₅₀ = 0.59 ± 0.07 μM) with significant selectivity (SI = 4.51) compared to imatinib (IC₅₀ = 5.46 ± 0.85 μM; SI = 4.60). Based on its superior cytotoxic activity, the analog AQQ13 was selected for further mechanistic studies including determination of its apoptotic effects on K562 cell line via annexin V/ethidium homodimer III staining potency, ABL1 kinase inhibitory activity, and DNA cleaving capacity. Results ascertained that the analog AQQ13 induced apoptosis in K562 cell line with notable DNA-cleaving activity. However, AQQ13 demonstrated weak ABL1 inhibition indicating the correlation between anti-K562 and anti-ABL1 activities. In continuance, respectively conducted in silico molecular docking and Absorption, Distribution, Metabolism, and Excretion (ADME) studies drew attention to enhanced binding interactions of AQQ13 towards DNA and its high compatibility with the potential limits of specified pharmacokinetic parameters making it as a potential anti-leukemic drug candidate. Our findings may provide a new insight for further development of novel quinolinequinone-based anticancer analogs against CML.

Identification of a new class of potent aldose reductase inhibitors: Design, microwave-assisted synthesis, in vitro and in silico evaluation of 2-pyrazolines

Aldose reductase (AR) acts as a multi-disease target for the design and development of therapeutic agents for the management of diabetic complications as well as non-diabetic diseases. In the search for potent AR inhibitors, the microwave-assisted synthesis of twenty new compounds with a 1,3-diaryl-5-(4-fluorophenyl)-2-pyrazoline moiety as a common fragment in their structure (1-20) was carried out efficiently. Compounds 1-20 were subjected to in vitro studies, which were conducted to assess their AR inhibitory effects and cytotoxicity towards L929 mouse fibroblast (normal) cells. Among these compounds, 1-(3-bromophenyl)-3-(4-piperidinophenyl)-5-(4-fluorophenyl)-2-pyrazoline (20) was identified as the most promising AR inhibitor with an IC₅₀ value of 0.160 ± 0.005 μM exerting competitive inhibition with a K_i value of 0.019 ± 0.001 μM as compared to epalrestat (IC₅₀ = 0.279 ± 0.001 μM; K_i = 0.801 ± 0.023 μM) and quercetin (IC₅₀ = 4.120 ± 0.123 μM; K_i = 6.082 ± 0.272 μM). Compound 20 displayed cytotoxicity towards L929 cells with an IC₅₀ value of 18.75 ± 1.06 μM highlighting its safety as an AR inhibitor. Molecular docking studies suggested that π-π stacking interactions occurred between the m-bromophenyl moiety of compound 20 and Trp21. Based on in silico pharmacokinetic studies, compound 20 was found to possess favorable oral bioavailability and drug-like properties. It can be concluded that compound 20 is a potential orally bioavailable AR inhibitor for the management of diabetic complications as well as non-diabetic diseases.

Structure based design, synthesis, and evaluation of anti-CML activity of the quinolinequinones as LY83583 analogs

Quinone-based small molecules are the promising structures for antiproliferative drug design and can induce apoptosis in cancer cells. Among them, one of the quinolinequinones, named as 6-anilino-5,8-quinolinequinone, LY83583 has the ability to inhibit the growth of cancer cells as an inhibitor of cyclase. The biological potential of all synthesized compounds as the analogs of the identified lead molecule LY83583 that possessed the antiproliferative efficiency was determined. The two series of the LY83583 analogs containing electron-withdrawing or electron-donating group(s) were synthesized and subsequently in vitro evaluated for their cytotoxic activity against K562, Jurkat, MT-2, and HeLa cell lines using MTT assay. All the LY83583 analogs showed antiproliferative activity with good IC₅₀ values (less than positive control imatinib). Four analogs from each series were also selected for the determination of selectivity against human peripheral blood mononuclear cells (PBMCs). The analog AQQ15 showed high potency towards all cancer cell lines with almost similar selectivity of imatinib. In order to get a better insight into cytotoxic effects of the analog AQQ15 in K562 cells, further apoptotic effects due to annexin V/ethidium homodimer III staining, ABL1 kinase inhibition, and DNA cleaving ability were examined. The analog AQQ15 induced apoptotic cell death in K562 cells with 34.6% compared to imatinib (6.5%). This analog showed no considerable ABL1 kinase inhibitory activity but significant DNA cleavage activity indicating DNA fragmentation-induced apoptosis. Besides, molecular docking studies revealed that the analog AQQ15 established proper interactions with the deoxyribose sugar attached with the nucleobases adenine and guanidine respectively, in the minor groove of the double helix of DNA. In silico predicted pharmacokinetic parameters of this analog were found to comply with the standard range making it an efficient anticancer drug candidate for further research.

A New Series of Antileukemic Agents: Design, Synthesis, In Vitro and In Silico Evaluation of Thiazole-Based ABL1 Kinase Inhibitors

BACKGROUND

After the approval of imatinib, more than 25 antitumor agents targeting kinases have been approved, and several promising candidates are at various stages of clinical evaluation.

OBJECTIVES

Due to the importance of the thiazole scaffold in targeted anticancer drug discovery, the goal of this work is to identify new thiazolyl hydrazones as potent ABL1 kinase inhibitors for the management of Chronic Myeloid Leukemia (CML).

METHODS

New thiazolyl hydrazones (2a-p) were synthesized and investigated for their cytotoxic effects on the K562 CML cell line. Compounds 2h, 2j and 2l showed potent anticancer activity against K562 cell line. The cytotoxic effects of these compounds on other leukemia (HL-60, MT-2 and Jurkat) and HeLa human cervical carcinoma cell lines were also investigated. Furthermore, their cytotoxic effects on Mitogen-Activated Peripheral Blood Mononuclear Cells (MA-PBMCs) were evaluated to determine their selectivity. Due to its selective and potent anticancer activity, compound 2j was benchmarked for its apoptosis-inducing potential on K562 cell line and inhibitory effects on eight different Tyrosine Kinases (TKs), including ABL1 kinase. In order to investigate the binding mode of compound 2j into the ATP binding site of ABL1 kinase (PDB: 1IEP), a molecular docking study was conducted using MOE 2018.01 program. The QikProp module of Schrödinger's Molecular modelling package was used to predict the pharmacokinetic properties of compounds 2a-p.

RESULTS

4-(4-(Methylsulfonyl)phenyl)-2-[2-((1,3-benzodioxol-4-yl)methylene)hydrazinyl]thiazole (2j) showed antiproliferative activity against K562 cell line with an IC₅₀ value of 8.87±1.93 μM similar to imatinib (IC50= 6.84±1.11μM). Compound 2j was found to be more effective than imatinib on HL-60, Jurkat and MT-2 cells. Compound 2j also showed cytotoxic activity against HeLa cell line similar to imatinib. The higher selectivity index value of compound 2j than imatinib indicated that its antiproliferative activity was selective. Compound 2j also induced apoptosis in K562 cell line more than imatinib. Among eight TKs, compound 2j showed the strongest inhibitory activity against ABL1 kinase enzyme (IC₅₀= 5.37±1.17μM). According to molecular docking studies, compound 2j exhibited high affinity to the ATP binding site of ABL1 kinase, forming significant intermolecular interactions. On the basis of in silico studies, this compound did not violate Lipinski's rule of five and Jorgensen's rule of three.

CONCLUSION

Compound 2j stands out as a potential orally bioavailable ABL1 kinase inhibitor for the treatment of CML.

A new series of 2,4-thiazolidinediones endowed with potent aldose reductase inhibitory activity

In an effort to identify potent aldose reductase (AR) inhibitors, 5-(arylidene)thiazolidine-2,4-diones (1–8), which were prepared by the solvent-free reaction of 2,4-thiazolidinedione with aromatic aldehydes in the presence of urea, were examined for their in vitro AR inhibitory activities and cytotoxicity. 5-(2-Hydroxy-3-methylbenzylidene)thiazolidine-2,4-dione (3) was the most potent AR inhibitor in this series, exerting uncompetitive inhibition with a K i value of 0.445 ± 0.013 µM. The IC50 value of compound 3 for L929 mouse fibroblast cells was determined as 8.9 ± 0.66 µM, pointing out its safety as an AR inhibitor. Molecular docking studies suggested that compound 3 exhibited good affinity to the binding site of AR (PDB ID: 4JIR). Based upon in silico absorption, distribution, metabolism, and excretion data, the compound is predicted to have favorable pharmacokinetic features. Taking into account the in silico and in vitro data, compound 3 stands out as a potential orally bioavailable AR inhibitor for the management of diabetic complications as well as nondiabetic diseases.

Synthesis of New Bis-pyrazolines Endowed with Potent Antifungal Activity against Candida albicans and Aspergillus niger

Background:

Due to the increasing number of cases of invasive fungal infections (IFIs), there is an urgent need to identify potent antifungal agents capable of combating IFIs. Pyrazolines are one such class of therapeutically active agents that could be considered to fulfill this need.

Objective:

In this context, this paper aims to identify two new series of bis-pyrazolines endowed with potent antifungal activity against Candida albicans and Aspergillus niger.

Methods:

Two new series of bis-pyrazolines (4a-i, 5a-e) were synthesized through an efficient and versatile synthetic procedure. The compounds were screened for their antifungal effects on C. albicans and A. niger using a broth microdilution method. Their cytotoxic effects on NIH/3T3 mouse embryonic fibroblast cells were determined using MTT assay. Molecular docking studies were performed in the active site of lanosterol 14α-demethylase (CYP51) to shed light on their antifungal effects using Schrödinger’s Maestro molecular modeling package.

Results:

5,5'-(1,4-Phenylene)bis[1-(2-(5-phenyl-1,3,4-oxadiazol-2-yl)thio)acetyl)-3-(2-thienyl)-4,5- dihydro-1H-pyrazole] (4a) and 5,5'-(1,4-phenylene)bis[1-(2-(4-(2-hydroxyethyl)-1-piperazinylthiocarbamoyl) thio)acetyl)-3-(2-thienyl)-4,5-dihydro-1H-pyrazole] (5a) were found as the most promising antifungal agents in this series. Compounds 4a and 5a showed pronounced antifungal activity against C. albicans (MIC= 0.016 mg/mL) and A. niger (MIC= 0.008 mg/mL). Based on MTT assay, their antifungal effects were selective (IC50 > 0.500 mg/mL for NIH/3T3 cell line). Molecular docking studies suggested that compounds 5a-e might show their anticandidal effects via CYP51 inhibition in regard to their stronger interactions in the active site of CYP51.

Conclusion:

Compounds 4a and 5a stand out as potential antifungal agents for the management of IFIs caused by C. albicans and A. niger.

Pyrazole Incorporated New Thiosemicarbazones: Design, Synthesis and Investigation of DPP-4 Inhibitory Effects

Dipeptidyl peptidase-4 (DPP-4) inhibition has been recognized as a promising approach to develop safe and potent antidiabetic agents for the management of type 2 diabetes. In this context, new thiosemicarbazones (2a-o) were prepared efficiently by the reaction of aromatic aldehydes with 4-[4-(1H-pyrazol-1-yl)phenyl]thiosemicarbazide (1), which was obtained via the reaction of 4-(1H-pyrazol-1-yl)phenyl isothiocyanate with hydrazine hydrate. Compounds 2a-o were evaluated for their DPP-4 inhibitory effects based on a convenient fluorescence-based assay. 4-[4-(1H-pyrazol-1-yl)phenyl]-1-(4-bromobenzylidene)thiosemicarbazide (2f) was identified as the most effective DPP-4 inhibitor in this series with an IC₅₀ value of 1.266 ± 0.264 nM when compared with sitagliptin (IC₅₀ = 4.380 ± 0.319 nM). MTT test was carried out to assess the cytotoxic effects of compounds 2a-o on NIH/3T3 mouse embryonic fibroblast (normal) cell line. According to cytotoxicity assay, compound 2f showed cytotoxicity towards NIH/3T3 cell line with an IC₅₀ value higher than 500 µM pointing out its favourable safety profile. Molecular docking studies indicated that compound 2f presented π-π interactions with Arg358 and Tyr666 via pyrazole scaffold and 4-bromophenyl substituent, respectively. Overall, in vitro and in silico studies put emphasis on that compound 2f attracts a great notice as a drug-like DPP-4 inhibitor for further antidiabetic research.

Design, Synthesis, In vitro and In silico Evaluation of New Hydrazonebased Antitumor Agents as Potent Akt Inhibitors

Background:

Akt is overexpressed or activated in a variety of human cancers, including gliomas, lung, breast, ovarian, gastric and pancreatic carcinomas. Akt inhibition leads to the induction of apoptosis and inhibition of tumor growth and therefore extensive efforts have been devoted to the discovery of potent antitumor drugs targeting Akt.

Objectives:

The objective of this work was to identify potent anticancer agents targeting Akt.

Methods:

New hydrazone derivatives were synthesized and investigated for their cytotoxic effects on 5RP7 H-ras oncogene transformed rat embryonic fibroblast and L929 mouse embryonic fibroblast cell lines. Besides, the apoptotic effects of the most active compounds on 5RP7 cell line were evaluated using flow cytometry. Their Akt inhibitory effects were also investigated using a colorimetric assay. In silico docking and Absorption, Distribution, Metabolism and Excretion (ADME) studies were also performed using Schrödinger’s Maestro molecular modeling package.

Results and Discussion:

Compounds 3a, 3d, 3g and 3j were found to be effective on 5RP7 cells (with IC50 values of <0.97, <0.97, 1.13±0.06 and <0.97 μg/mL, respectively) when compared with cisplatin (IC50= 1.87±0.15 μg/mL). It was determined that these four compounds significantly induced apoptosis in 5RP7 cell line. Among them, N'-benzylidene-2-[(4-(4-methoxyphenyl)pyrimidin- 2-yl)thio]acetohydrazide (3g) significantly inhibited Akt (IC50= 0.5±0.08 μg/mL) when compared with GSK690693 (IC50= 0.6±0.05 μg/mL). Docking studies suggested that compound 3g showed good affinity to the active site of Akt (PDB code: 2JDO). According to in silico ADME studies, the compound also complies with Lipinski's rule of five and Jorgensen's rule of three.

Conclusion:

Compound 3g stands out as a potential orally bioavailable cytotoxic agent and apoptosis inducer targeting Akt.

A New Series of Triazolothiadiazines as Potential Anticancer Agents for Targeted Therapy of Non-small Cell Lung and Colorectal Cancers: Design, Synthesis, In Silico and In Vitro Studies Providing Mechanistic Insight into Their Anticancer Potencies

BACKGROUND

Targeted therapies acting on specific molecular targets in cancer cells with better curative efficacy and lower toxicity have come into prominence for the management of non-small cell lung cancer (NSCLC) and colorectal cancer (CRC). COX-2 stands out as a plausible target for anticancer agents due to its pivotal role in tumor initiation, progression and invasion.

OBJECTIVES

Due to the importance of triazolothiadiazine scaffold in targeted anticancer drug discovery, the aim of this work is the design of new triazolothiadiazines as potential anticancer agents for the targeted therapy of NSCLC and CRC.

METHODS

New triazolo[3,4-b]-1,3,4-thiadiazines (2a-g) were synthesized via the ring closure reactions of 2-bromo-1- arylethanones with 4-amino-5-((5-methoxy-2-methyl-1H-indol-3-yl)methyl)-2,4-dihydro-3H-1,2,4-triazole-3-thione (1), which was obtained via the solvent-free reaction of 5-methoxy-2-methyl-3-indoleacetic acid with thiocarbohydrazide. MTT assay was performed to determine their cytotoxic effects on A549 human lung adenocarcinoma, Caco-2 human colorectal adenocarcinoma and CCD-19Lu human lung fibroblast cells. The most potent compounds were evaluated for their effects on apoptosis, caspase-3, mitochondrial membrane potential, cell cycle, ultrastructural morphological changes and COX-2 in A549 and Caco-2 cells. In silico docking and Absorption, Distribution, Metabolism and Excretion (ADME) studies were also performed using Schrödinger's Maestro molecular modeling package.

RESULTS

6-(4-Chlorophenyl)-3-[(5-methoxy-2-methyl-1H-indol-3-yl)methyl]-7H-[1,2,4]triazolo[3,4-b][1,3,4]thiadiazine (2e) was the most potent and selective anticancer agent in this series against A549 and Caco-2 cell lines. Compound 2e induced early apoptosis, caused mitochondrial membrane depolarization and arrested cell cycle at G0/G1 phase in A549 cells. On the other hand, compound 2e triggered intrinsic apoptotic pathway involving caspase-3 activation in Caco-2 cells. Compound 2e caused apoptotic morphological changes in both cancer cell lines. The cytotoxic and apoptotic effects of this compound on CRC were found to be related to its selective COX-2 inhibitory activity. According to molecular docking studies, compound 2e showed good affinity to the active site of COX-2 (PDB code: 4COX). Based on in silico ADME studies, the compound is predicted to possess a favorable ADME profile.

CONCLUSION

According to in vitro and in silico studies, compound 2e was identified as a potential orally bioavailable anticancer agent for COX-2-targeted therapy of CRC.

A new series of benzoxazole-based SIRT1 modulators for targeted therapy of non-small-cell lung cancer

In an attempt to identify potential anticancer agents for non-small-cell lung cancer (NSCLC) targeting sirtuin 1 (SIRT1), the synthesis of a new series of benzoxazoles (3a - i) was carried out through a facile and versatile synthetic route. The compounds were evaluated for their cytotoxic effects on A549 human lung adenocarcinoma and NIH/3T3 mouse embryonic fibroblast cells using the MTT assay. 2-[(5-Nitro-1H-benzimidazol-2-yl)thio]-N-(2-methylbenzoxazol-5-yl)acetamide (3e) and 2-[(5-chloro-1H-benzimidazol-2-yl)thio]-N-(2-methylbenzoxazol-5-yl)acetamide (3g) were the most potent and selective anticancer agents in this series against the A549 cell line, with IC₅₀ values of 46.66 ± 11.54 and 55.00 ± 5.00 µM, respectively. The flow cytometry-based apoptosis detection assay was performed to determine their effects on apoptosis in A549 cells. Both compounds induced apoptosis in a dose-dependent manner. The effects of compounds 3e and 3g on SIRT1 activity were determined. On the basis of in vitro studies, it was observed that compound 3g caused a significant decrease in SIRT1 levels in a dose-dependent manner, whereas compound 3e increased the SIRT1 levels. According to molecular docking studies, the substantial alteration in the type of action could be attributed to the difference between the interactions of compounds 3e and 3g with the same residues in the active site of SIRT1 (PDB code: 4IG9). On the basis of in silico ADME (absorption, distribution, metabolism, and excretion) studies, these compounds are predicted to possess favorable ADME profiles. According to the in vitro and in silico studies, compounds 3e and 3g, small-molecule SIRT1 modulators, were identified as potential orally bioavailable anticancer agents for the targeted therapy of NSCLC.

Design, synthesis, in vitro and in silico investigation of aldose reductase inhibitory effects of new thiazole-based compounds

Aldose reductase (AR) catalyzes the NADPH-dependent reduction of glucose to sorbitol in the polyol pathway, which plays an important role in the development of diabetic complications including cataract, retinopathy, nephropathy, and neuropathy. AR has been considered as an important target to heal these long-term diabetic complications and for this reason the development of new AR inhibitors is an important approach in modern medicinal chemistry. In the current study, new 4-aryl-2-[2-((3,4-dihydro-2H-1,5-benzodioxepine-7-yl)methylene)hydrazinyl]thiazole derivatives (1-12) were synthesized and screened for their inhibitory effects on AR which was purified by diverse chromatographic methods with a yield of 1.40% and a specific activity of 2.00 EU/mg. All compounds were determined as promising AR inhibitors with the K_i values in the range of 0.018 ± 0.005 μM-3.746 ± 1.321 μM compared to the quercetin (K_i = 7.025 ± 1.780 μM). In particular, 4-(4-cyanophenyl)-2-[2-((3,4-dihydro-2H-1,5-benzodioxepin-7-yl)methylene)hydrazinyl]thiazole (3) was detected as the most potential AR inhibitor in this series with the K_i value of 0.018 ± 0.005 µM and the compound showed competitive AR inhibition. The cytotoxic effects of compounds 1-12 were investigated on L929 mouse fibroblast (healthy) cells using MTT assay and all these compounds were defined as non-cytotoxic agents against L929 cells. Molecular docking studies, which were employed to determine the affinity of compounds 1-12 into the active site of AR, highlighted that the thiazole scaffold of all these compounds presented π-π stacking interactions with Trp20 and Phe122. According to both in vitro and in silico assays, these potential AR inhibitors may have great importance in the prevention of diabetic microvascular conditions.

A Series of Furan-based Hydrazones: Design, Synthesis, and Evaluation of Antimicrobial Activity, Cytotoxicity and Genotoxicity

Background:

Hydrazones, frequently occurring motifs in many bioactive molecules, have attracted a great deal of interest as potent antimicrobial agents.

Objective:

The aim of this work was to design and synthesize new hydrazone-based antimicrobial agents.

Methods:

4-[2-((5-Arylfuran-2-yl)methylene)hydrazinyl]benzonitrile derivatives (1-10) were obtained via the reaction of 4-cyanophenylhydrazine hydrochloride with 5-arylfurfurals. Compounds 1-10 were evaluated for their antimicrobial effects using a broth microdilution method. Their cytotoxic effects on NIH/3T3 mouse embryonic fibroblast cell line were determined using XTT assay. The most effective antimicrobial agents were investigated for their genotoxic effects using Ames MPF assay. In silico docking and Absorption, Distribution, Metabolism and Excretion (ADME) studies were also performed using Schrödinger’s Maestro molecular modeling package.

Results:

The antifungal effects of the compounds were more significant than their antibacterial effects. Compound 5 bearing 3-nitrophenyl moiety was the most potent antifungal agent against Candida albicans, Trichoderma harzianum and Fusarium species, whereas compound 10 bearing 4- chloro-2-nitrophenyl moiety was the most effective antifungal agent on Aspergillus ochraceus. According to XTT and Ames MPF assays, these compounds were neither cytotoxic nor genotoxic at the concentrations tested. Docking studies suggested that these compounds showed good affinity to the active site of lanosterol 14α-demethylase (CYP51) (PDB code: 5V5Z) and interacted with the key residues such as Hem601 and Cys470. Based on in silico ADME studies, the compounds are expected to have high oral bioavailability.

Conclusion:

According to the in vitro and in silico studies, compounds 5 and 10 stand out as potential orally bioavailable antifungal agents for further studies.

Synthesis and Evaluation of a Series of 1,3,4-Thiadiazole Derivatives as Potential Anticancer Agents

BACKGROUND AND METHODS

In an attempt to develop potent antitumor agents, the synthesis of a series of N-(6-substituted benzothiazol-2-yl)-2-[(5-(arylamino)-1,3,4-thiadiazol-2-yl)thio]acetamides (1-14) was described and their cytotoxic effects on A549 human lung adenocarcinoma, MCF-7 human breast adenocarcinoma, HepG2 human hepatocellular carcinoma and NIH/3T3 mouse embryonic fibroblast cell lines were investigated using MTT assay.

RESULTS

Phenyl-substituted compounds (8-14) were found to be more effective than naphthyl-substituted compounds (1-7) on cancer cells. Compounds 8, 9, 10, 12, 13 and 14 were identified as the most potent anticancer agents on MCF-7 and HepG2 cell lines and therefore their effects on DNA synthesis and apoptosis/necrosis in MCF-7 cell line were evaluated. Among these compounds, N-(6-methoxybenzothiazol-2-yl)-2-[(5- (phenylamino)-1,3,4-thiadiazol-2-yl)thio]acetamide (13) was the most selective anticancer agent against MCF-7 and HepG2 cell lines with a SI value of 100. On the other hand, compounds 8, 9, 10, 12, 13 and 14 inhibited DNA synthesis in MCF-7 cell line in a dose-dependent manner. Flow cytometric analyses clearly indicated that the compounds showed significant anticancer activity against MCF-7 cell line via the induction of apoptosis dose dependently.

CONCLUSION

According to in vitro assays, compounds 8, 9, 10, 12, 13 and 14 stand out as promising candidates for further studies.

Biological evaluation of a series of benzothiazole derivatives as mosquitocidal agents

Aedes aegypti is associated with the transmission of numerous human and animal diseases, such as yellow fever, dengue fever, chikungunya, and more recently Zika virus. Emerging insecticide resistance has created a need to develop new mosquitocidal agents for effective control operations. A series of benzothiazole-piperidine derivatives (1-24) were investigated for their larvicidal and adulticidal effects on Ae. aegypti It was observed that compounds 2, 4, 6, 7, 8, 11 and 13 showed notable larvicidal activity. Furthermore, compounds 6 and 10 showed promising adulticidal activity. Based on the mosquitocidal properties of these compounds, docking studies were also carried out in the active site of the AeSCP2 enzyme to explore any insights into further in vitro enzyme studies. Docking results indicated that all these active compounds showed reasonable interactions with critical residues in the active site of this enzyme. This outcome suggested that these compounds might show their larvicidal and adulticidal effects via the inhibition of AeSCP2. According to in vitro and in silico studies, compounds 2, 4, 6, 7, 8, 10, 11 and 13 stand out as candidates for further studies.

Comprehensive Study on Thiadiazole-Based Anticancer Agents Inducing Cell Cycle Arrest and Apoptosis/Necrosis Through Suppression of Akt Activity in Lung Adenocarcinoma and Glioma Cells

Objectives

Akt is considered as an attractive target for anticancer drug discovery and development and therefore extensive efforts have been devoted to the discovery of new potent anticancer agents targeting Akt.

Materials and Methods

Due to the importance of thiadiazoles for anticancer drug discovery, herein eight 1,3,4-thiadiazole derivatives were investigated for their cytotoxic effects on C6 rat glioma and A549 human lung adenocarcinoma cell lines using the MTT assay. The effects of the most promising anticancer agents on apoptosis, caspase-3 activation, mitochondrial membrane potential, and cell cycle arrest were determined on a BD FACSAria (I) flow cytometer. Akt activity was measured in the C6 and A549 cell lines using an ELISA colorimetric method. Schrödinger's Maestro molecular modeling package was used to explore the possible binding modes of compounds 3 and 8 in the active site of Akt enzyme (PDB code: 3OW4).

Results

N-(4-Chlorophenyl)-2-[(5-((4-nitrophenyl)amino)-1,3,4-thiadiazol-2-yl)thio]acetamide (3) and N-(6-nitrobenzothiazol-2-yl)-2-[(5-((4- nitrophenyl)amino)-1,3,4-thiadiazol-2-yl)thio]acetamide (8) induced apoptosis and cell cycle arrest in the C6 cell line through inhibition of Akt activity (92.36% and 86.52%, respectively). The docking results of compounds 3 and 8 indicated that π-π interactions, H bonds, and salt-bridge formation were responsible for the observed Akt inhibitory activity.

Conclusion

According to in vitro and docking studies, compounds 3 and 8 stand out as promising antiglioma agents.

Synthesis and Evaluation of a New Series of Arylidene Indanones as Potential Anticancer Agents

Background:

Arylidene indanones have attracted a great deal of interest due to their outstanding therapeutic applications. In particular, considerable research has pointed out the importance of arylidene indanones in the field of cancer research.

Objective:

The aim of the current work was to design and synthesize arylidene indanone-based anticancer agents.

Method:

New arylidene indanones were obtained via the Claisen-Schmidt condensation of 5-chloro-6-methoxy- 2,3-dihydro-1H-inden-1-one with p-substituted benzaldehyde derivatives. MTT assay was performed to evaluate their cytotoxic effects on MCF-7 human breast adenocarcinoma, HeLa human cervix carcinoma and NIH/3T3 mouse embryonic fibroblast cell lines. The most effective derivatives were evaluated for their DNA synthesis inhibitory and apoptotic effects. The most apoptotic compounds were also investigated for their effects on caspase-3 activation in HeLa cells. The binding interactions of the most effective caspase-3 activator at the active site of caspase-3 were confirmed through molecular docking studies using Schrodinger’s Maestro molecular modeling package.

Results and Conclusion:

Compounds 2, 3, 4, 5, 6 and 7 exhibited selective anticancer activity against HeLa cells, whilst compounds 7 and 10 showed selective anticancer activity against MCF-7 cells. Compound 10 caused significant DNA synthesis inhibition on MCF-7 cells, whereas compound 3 caused significant DNA synthesis inhibition on HeLa cells. Compounds 2 and 3 were determined as the most apoptotic agents against HeLa cells, whereas compounds 7 and 10 showed apoptotic activity against MCF-7 cells. Besides, compound 2 was identified as the most effective compound on caspase-3 activation in HeLa cells. Docking studies showed that compound 2 interacted with the residues His121 and Tyr204 forming π-π stacking interactions.

New Benzodioxole-based Pyrazoline Derivatives: Synthesis and Anticandidal, In silico ADME, Molecular Docking Studies

Background:

Azoles are commonly used in the treatment and prevention of fungal infections. They suppress fungal growth by acting on the heme group of lanosterol 14α-demethylase enzyme (CYP51), thus blocking the biosynthesis of ergosterol. </P><P> Objectives: Due to the importance of pyrazolines in the field of antifungal drug design, we aimed to design and synthesize new pyrazoline-based anticandidal agents.

Methods:

New pyrazoline derivatives were synthesized via the reaction of 1-(chloroacetyl)-3-(2- thienyl)-5-(1,3-benzodioxol-5-yl)-2-pyrazoline with aryl thiols. These compounds were evaluated for their in vitro antifungal effects on Candida species. Docking studies were performed to predict the affinity of the most effective anticandidal agents to substrate binding site of CYP51. Furthermore, MTT assay was performed to determine the cytotoxic effects of the compounds on NIH/3T3 mouse embryonic fibroblast cell line. A computational study for the prediction of ADME properties of all compounds was also carried out.

Results:

Compounds 5, 8, 10 and 12 were found as the most potent anticandidal agents against Candida albicans and Candida glabrata in this series with the same MIC values of ketoconazole and they also exhibited low toxicity against NIH/3T3 cells. Docking results indicated that all these compounds showed good binding affinity into the active site of CYP51. In particular, chloro substituted compounds 8 and 12 bind to CYP51 through direct coordination with the heme group. According to in silico studies, compound 8 only violated one parameter of Lipinski’s rule of five, making it a potential orally bioavailable agent.

Conclusion:

Compound 8 was defined as a promising candidate for further in vitro and in vivo studies.

Design, Synthesis, and Neuroprotective Effects of a Series of Pyrazolines against 6-Hydroxydopamine-Induced Oxidative Stress

Parkinson's disease (PD) is a chronic, progressive, and age-related neurodegenerative disorder characterized by the loss of midbrain dopaminergic neurons caused by the accumulation of free radicals and oxidative stress. Based on the neuroprotective properties of 2-pyrazoline derivatives, in the current work, 1-(phenyl/4-substituted phenyl)-3-(2-furanyl/thienyl)-5-aryl-2-pyrazolines (3a⁻i, 4a⁻i) were synthesized via the cyclization of the chalcones (1, 2) with suitable phenylhydrazine hydrochloride derivatives. All these compounds were investigated for their neuroprotective effects using an in vitro 6-hydroxydopamine (6-OHDA)-induced neurotoxicity model of PD in the rat pheochromocytoma (PC-12) Adh cell line. In addition, some different pharmacokinetic parameters of all compounds were in silico predicted by the QikProp module of Schrödinger's Maestro molecular modeling package. 4-Methylsulfonylphenyl substituted compounds 3h (20%) and 4h (23%) were determined as the most promising neuroprotective agents related to their inductive roles in cell viability when compared with the 6-OHDA-positive control group (43% and 42%, respectively). Moreover, in silico pharmacokinetic results indicated that all compounds were within the acceptable range intended for human use. According to both in vitro and in silico studies, compounds 3h and 4h draw attention as potential orally bioavailable therapeutic drug candidates against neurodegeneration in PD.

Design, synthesis, in vitro and in silico evaluation of a new series of oxadiazole-based anticancer agents as potential Akt and FAK inhibitors

In the current work, new 1,3,4-oxadiazole derivatives were synthesized and investigated for their cytotoxic effects on A549 human lung adenocarcinoma, C6 rat glioma and NIH/3T3 mouse embryonic fibroblast cell lines. Compounds 2, 6 and 9 were found to be the most potent anticancer agents against A549 and C6 cell lines and therefore their effects on apoptosis, caspase-3 activation, Akt, FAK, mitochondrial membrane potential and ultrastructural morphological changes were evaluated. N-(5-Nitrothiazol-2-yl)-2-[[5-[((5,6,7,8-tetrahydronaphthalen-2-yl)oxy)methyl]-1,3,4-oxadiazol-2-yl]thio]acetamide (9) increased early and late apoptotic cell population in A549 and C6 cells more than cisplatin and caused more mitochondrial membrane depolarization in both cell lines than cisplatin. On the other hand, N-(6-methoxybenzothiazol-2-yl)-2-[[5-[((5,6,7,8-tetrahydronaphthalen-2-yl)oxy)methyl]-1,3,4-oxadiazol-2-yl]thio]acetamide (6) caused higher caspase-3 activation than cisplatin in both cell lines. Compound 6 showed significant Akt inhibitory activity in both cell lines. Moreover, compound 6 significantly inhibited FAK (Phospho-Tyr397) activity in C6 cell line. Molecular docking simulations demonstrated that compound 6 fitted into the active sites of Akt and FAK with high affinity and substrate-specific interactions. Furthermore, compounds 2, 6 and 9 caused apoptotic morphological changes in both cell lines obtained from micrographs by transmission electron microscopy. A computational study for the prediction of ADME properties of all compounds was also performed. These compounds did not violate Lipinski's rule, making them potential orally bioavailable anticancer agents.

Design, Synthesis, and Evaluation of a New Series of Thiazole-Based Anticancer Agents as Potent Akt Inhibitors

In an attempt to develop potent anticancer agents targeting Akt, new thiazole derivatives (1⁻10) were synthesized and investigated for their cytotoxic effects on A549 human lung adenocarcinoma, C6 rat glioma, and NIH/3T3 (healthy) mouse embryonic fibroblast cell lines. The most potent compounds were also investigated for their effects on apoptosis and Akt pathway. The most promising anticancer agent was found to be 2-[2-((4-(4-cyanophenoxy)phenyl)methylene)hydrazinyl]-4-(4-cyanophenyl)thiazole (6), due to its selective inhibitory effects on A549 and C6 cells with IC₅₀ values of 12.0 ± 1.73 µg/mL and 3.83 ± 0.76 µg/mL, respectively. Furthermore, compound 6 increased early and late apoptotic cell population (32.8%) in C6 cell line more than cisplatin (28.8%) and significantly inhibited the Akt enzyme. The molecular docking study was performed to predict the possible binding modes of compounds A, 6, and 8 inside the active site of Akt (PDB code: 4EJN). Molecular docking simulations were found to be in accordance with in vitro studies and, hence, supported the biological activity. A computational study for the prediction of absorption, distribution, metabolism and excretion (ADME) properties of all compounds was also performed. On the basis of Lipinski's rule of five, the compounds were expected to be potential orally bioavailable agents.

In silico Molecular Docking and ADME Studies of 1,3,4-Thiadiazole Derivatives in Relation to in vitro PON1 Activity

BACKGROUND

Paraoxonase 1 (PON1) is a paraoxonase, arylesterase and lactonase associated with protection of lipoproteins and cell membranes against oxidative modification.

OBJECTIVE

Based on antioxidative properties of PON1 and significance of 1,3,4-thiadiazoles in pharmaceutical chemistry, herein we aimed to evaluate the potentials of 1,3,4-thiadiazole derivatives as PON1 activators.

METHODS

2-[[5-(2,4-Difluoro/dichlorophenylamino)-1,3,4-thiadiazol-2-yl]thio]acetophenone derivatives (1-18) were in vitro evaluated for their activator effects on PON1 which was purified using ammonium sulfate precipitation (60-80%) and DEAE-Sephadex anion exchange chromatography. Molecular docking studies were performed for the detection of affinities of all compounds to the active site of PON1. Moreover, Absorption, Distribution, Metabolism and Excretion (ADME) properties of all compounds were also in silico predicted. In silico molecular docking and ADME studies were carried out according to modules of Schrodinger's Maestro molecular modeling package.

RESULTS

All compounds, particularly compounds 10, 13 and 17, were determined as promising PON1 activators and apart from compound 1, all of them were detected in the active site of PON1. Besides, ADME results indicated that all compounds were potential orally bioavailable drug-like molecules.

CONCLUSION

PON1 activators, compounds 10, 13 and 17 stand out as potential drug candidates for further antioxidant studies and these compounds can be investigated for their therapeutic effects in many disorders such as atherosclerosis, diabetes mellitus, obesity, chronic liver inflammation and many more.

Synthesis and Biological Evaluation of New Quinoline-Based Thiazolyl Hydrazone Derivatives as Potent Antifungal and Anticancer Agents

Background:

In medicinal chemistry, thiazoles have gained great importance in antifungal and anticancer drug design and development.

Objectives:

The aim of this study was to synthesize new quinoline-based thiazolyl hydrazone derivatives and evaluate their anticandidal and anticancer effects.

Methods:

New thiazolyl hydrazone derivatives were evaluated for their anticandidal effects using disc diffusion method. Ames MPF assay was carried out to determine the genotoxicity of the most effective antifungal derivative. MTT assay was also performed to assess the cytotoxic effects of the compounds on A549 human lung adenocarcinoma, HepG2 human hepatocellular carcinoma, MCF- 7 human breast adenocarcinoma and NIH/3T3 mouse embryonic fibroblast (healthy) cell lines.

Methods:

Results: 4-(4-Fluorophenyl)-2-(2-((quinolin-4-yl)methylene)hydrazinyl)thiazole (4) showed antifungal activity against Candida albicans and Candida krusei in the concentration of 1 mg/mL. In MTT and Ames MPF tests, it was determined that compound 4 did not show cytotoxic and genotoxic effects. MTT assay indicated that 4-(naphthalen-2-yl)-2-(2-((quinolin-4-yl)methylene) hydrazinyl)thiazole (10) showed more selective anticancer activity than cisplatin against A549 and MCF-7 cell lines. Besides, 4-(4-chlorophenyl)-2-(2-((quinolin-4-yl)methylene)hydrazinyl)thiazole (5) exhibited more selective anticancer activity than cisplatin against HepG2 cell line.

Conclusion:

Due to their high selectivity index, these compounds are considered as candidate compounds to participate in further research.

Design, Synthesis, and Biological Evaluation of Novel 1,3,4-Thiadiazole Derivatives as Potential Antitumor Agents against Chronic Myelogenous Leukemia: Striking Effect of Nitrothiazole Moiety

In an attempt to develop potent antitumor agents, new 1,3,4-thiadiazole derivatives were synthesized and evaluated for their cytotoxic effects on multiple human cancer cell lines, including the K562 chronic myelogenous leukemia cell line that expresses the Bcr-Abl tyrosine kinase. N-(5-Nitrothiazol-2-yl)-2-((5-((4-(trifluoromethyl)phenyl)amino)-1,3,4-thiadiazol-2-yl)thio)acetamide (2) inhibited the Abl protein kinase with an IC₅₀ value of 7.4 µM and showed selective activity against the Bcr-Abl positive K562 cell line. Furthermore, a Bcr-Abl-compound 2 molecular modelling simulation highlighted the anchoring role of the nitrothiazole moiety in bonding and hydrophobic interaction with the key amino acid residues. These results provide promising starting points for further development of novel kinase inhibitors.

Synthesis and Evaluation of New Oxadiazole, Thiadiazole, and Triazole Derivatives as Potential Anticancer Agents Targeting MMP-9

Matrix metalloproteinases (MMPs) are important proteases involved in tumor progression including angiogenesis, tissue invasion, and migration. Therefore, MMPs have been reported as potential diagnostic and prognostic biomarkers in many types of cancer. New oxadiazole, thiadiazole, and triazole derivatives were synthesized and evaluated for their anticancer effects on A549 human lung adenocarcinoma and C6 rat glioma cell lines. In order to examine the relationship between their anticancer activity and MMP-9, the compounds were evaluated for their inhibitory effects on MMPs. N-(1,3-Benzodioxol-5-ylmethyl)-2-{[5-(((5,6,7,8-tetrahydronaphthalen-2-yl)oxy)methyl)-1,3,4-oxadiazol-2-yl]thio}acetamide (8) and N-(1,3-benzodioxol-5-ylmethyl)-2-[(5-phenyl-1,3,4-oxadiazol-2-yl)thio]acetamide (9) revealed promising cytotoxic effects on A549 and C6 cell lines similar to cisplatin without causing any toxicity towards NIH/3T3 mouse embryonic fibroblast cell line. Compounds 8 and 9 were also the most effective MMP-9 inhibitors in this series. Moreover, docking studies pointed out that compounds 8 and 9 had good affinity to the active site of the MMP-9 enzyme. The molecular docking and in vitro studies suggest that the MMP-9 inhibitory effects of compounds 8 and 9 may play an important role in lung adenocarcinoma and glioma treatment.

Synthesis and Evaluation of New Benzodioxole- Based Thiosemicarbazone Derivatives as Potential Antitumor Agents

New benzodioxole-based thiosemicarbazone derivatives were synthesized and evaluated for their cytotoxic effects on A549 human lung adenocarcinoma, C6 rat glioma and NIH/3T3 mouse embryonic fibroblast cells. In order to examine the correlation between anticancer activity and cholinesterases, the compounds were evaluated for their inhibitory effects on AChE and BuChE. The most effective anticancer agents were investigated for their effects on DNA synthesis, apoptosis and mitochondrial membrane potential. 4-(1,3-Benzodioxol-5-yl)-1-([1,1'-biphenyl]-4-ylmethylene)thiosemicarbazide (5) was identified as the most promising anticancer agent against C6 and A549 cell lines due to its inhibitory effects on C6 and A549 cells and low toxicity to NIH/3T3 cells. Compound 5 increased early and late apoptosis in A549 and C6 cells. Compound 5 also caused disturbance on mitochondrial membrane potential and showed DNA synthesis inhibitory activity in A549 and C6 cells. Compound 5 was investigated for SIRT1 inhibitory activity to provide mechanistic insight and for that purpose docking studies were also performed for this compound on SIRT1. On the other hand, compound 5 did not show any inhibitory activity against AChE and BuChE. This outcome pointed out that there is no relationship between anticancer activity of compound 5 and cholinesterases.

Synthesis and evaluation of new benzodioxole-based dithiocarbamate derivatives as potential anticancer agents and hCA-I and hCA-II inhibitors

In the current work, new benzodioxole-based dithiocarbamate derivatives were synthesized via the reaction of N-(1,3-benzodioxol-5-ylmethyl)-2-chloroacetamide with appropriate sodium salts of N,N-disubstituted dithiocarbamic acids. These derivatives were evaluated for their cytotoxic effects on A549 human lung adenocarcinoma and C6 rat glioma cell lines. N-(1,3-Benzodioxol-5-ylmethyl)-2-[4-(4-nitrophenyl)-1-piperazinylthiocarbamoylthio]acetamide (10) can be identified as the most promising anticancer agent against C6 cell line due to its notable inhibitory effect on C6 cells with an IC₅₀ value of 23.33 ± 7.63 μg/mL when compared with cisplatin (IC₅₀ = 19.00 ± 5.29 μg/mL). On the other hand, compound 10 did not show any significant cytotoxic activity against A549 cell line. The compounds were also tested for their in vitro inhibitory effects on hCA-I and hCA-II. Generally, the tested compounds were more effective on CAs than acetazolamide, the reference agent. Among these compounds, N-(1,3-benzodioxol-5-ylmethyl)-2-[(morpholinyl)thiocarbamoylthio]acetamide (3) and N-(1,3-benzodioxol-5-ylmethyl)-2-[(thiomorpholinyl)thiocarbamoylthio]acetamide (4) were found to be the most effective compounds on hCA-I with IC₅₀ values of 0.346 nM and 0.288 nM, and hCA-II with IC₅₀ values of 0.287 nM and 0.338 nM, respectively.

Synthesis and evaluation of naphthalene-based thiosemicarbazone derivatives as new anticancer agents against LNCaP prostate cancer cells

Fourteen new naphthalene-based thiosemicarbazone derivatives were designed as anticancer agents against LNCaP human prostate cancer cells and synthesized. MTT assay indicated that compounds 6, 8 and 11 exhibited inhibitory effect on LNCaP cells. Among these compounds, 4-(naphthalen-1-yl)-1-[1-(4-hydroxyphenyl)ethylidene)thiosemicarbazide (6), which caused more than 50% death on LNCaP cells, was chosen for flow cytometric analysis of apoptosis. Flow cytometric analysis pointed out that compound 6 also showed apoptotic effect on LNCaP cells. Compound 6 can be considered as a promising anticancer agent against LNCaP cells owing to its potent cytotoxic activity and apoptotic effect.