Synthesis, characterization, and pharmacological evaluation of some novel thiadiazoles and thiazoles incorporating pyrazole moiety as anticancer agents

Chemical and Biological Characterization of the Ethyl Acetate Fraction from the Red Sea Marine Sponge Hymedesmia sp

Hymedesmiidae is one of the largest families of marine sponges and stands out as an exceptional source of variable metabolites with diverse biological activities. In this study, the ethyl acetate fraction (HE) of a Hymedesmia sp. marine sponge from the Red Sea, Egypt, was analyzed for the first time using Ultra-performance liquid chromatography electrospray ionization tandem mass spectrometry (UPLC-ESI-MS/MS) analysis. The analysis tentatively identified 29 compounds in this fraction, including the isolation and identification of six compounds (two pyrimidine nucleosides, one purine, and two pyrimidine bases in addition to one cerebroside) for the first time. The structures of the isolated compounds were established by 1D and 2D NMR (nuclear magnetic resonance), MS (mass spectrometry), and IR (infrared) spectroscopy. Furthermore, the cytotoxic, antioxidant, and antimicrobial activities of the ethyl acetate fraction were evaluated in vitro. The fraction exhibited strong DPPH scavenging activity with an IC50 of 78.7 µg/mL, compared to ascorbic acid as a positive control with an IC50 of 10.6 µg/mL. It also demonstrated significant cytotoxic activity with IC50 values of 13.5 µg/mL and 25.3 µg/mL against HCT-116 and HEP-2 cell lines, respectively, compared to vinblastine as a positive control with IC50 values of 2.34 µg/mL and 6.61 µg/mL against HCT-116 and HEP-2, respectively. Additionally, the ethyl acetate fraction displayed promising antibacterial activity against S. aureus with a MIC value of 62.5 µg/mL, compared to ciprofloxacin as a positive control with MIC values of 1.56 µg/mL for Gram-positive bacteria and 3.125 µg/mL for Gram-negative bacteria. It also exhibited activity against E. coli and P. aeruginosa with MIC values of 250 µg/mL and 500 µg/mL, respectively. Briefly, this is the first report on the biological activities and secondary metabolite content of the ethyl acetate fraction of Hymedesmia sp. marine sponge, emphasizing the potential for further research against resistant bacterial and fungal strains, as well as different cancer cell lines. The ethyl acetate fraction of Hymedesmia sp. is a promising source of safe and unique natural drugs with potential therapeutic and pharmaceutical benefits.

Elucidating the structural basis for the enhanced antifungal activity of amide derivative against Candida albicans: a comprehensive computational investigation

The continuous search for more effective options against well-known pathogens such as Candida albicans remains the rationale for the search for novel lead compounds from various sources. This study aims to investigate the chemical structure, chemical properties, of 5-(2-((5-(((1S,3R) -3-(5-acetamido-1,3,4-thiadiazolidin-2-yl) cyclopentyl) methyl)-1,3,4-thiadiazolidin-2-yl)amino)-2-oxoethyl)-2-methyl-2,3-dihydro-1H-pyrazol-3-ide designated ATCTP using DFT method ωB97XD/-311 +  + g(2d, 2p) and the biological potential of compound ATCTP against Candida albicans using molecular docking and ADMET studies. Geometry optimization was carried out in DMSO, ethanol. gas and water revealing minute discrepancies in bond length and wider differences in bond angles. Frontier molecular orbital investigations reveal HOMO-LUMO energy gap magnitude in decreasing order of ATCTP_Gas > ATCTP_Water > ATCTP_ethanol > ATCTP_DMSO inferring that water influences chemical stability of the compound the most compared to ethanol and DMSO. Density of state investigations have revealed electron density contributions at corresponding energy peaks. In silico pharmacokinetic predicts ATCTP not to be cytotoxic, hepatotoxic, immunotoxic or mutagenic but probable mutagen. Molecular docking investigation of ATCTP against aspartic proteinase of Candida albicans (ID: 2QZX) in comparison with standard drug Fluconazole. Compound ATCTP had higher binding affinity (- 8.1 kcal/mol) compared to that of the standard drug fluconazole (- 5.6 kcal/mol) which records 4 conventional hydrogen interactions compared to 2 formed in the interaction of ATCTP + 2QZX. ATCTP also reports binding affinity of - 7.2 kcal/mol which reportedly surpassed that of 2QZX interaction with fluconazole (- 5.7 kcal/mol). ATCTP binds with lanosterol14-α-demethylase (5v5z) with binding affinity of - 9.7 kcal/mol binding to active site amino acid residues of the protein compared to fluconazole + 5v5z (- 8.0 kcal/mol). ATCTP is therefore recommended to be a lead compound for the possible design of a new and more effective anti-candida therapeutic compound.

Graphical abstract

Metabolites Profiling and In Vitro Biological Characterization of Different Fractions of Cliona sp. Marine Sponge from the Red Sea Egypt

Red Sea marine sponges are an important source of biologically active natural products. Therefore, the present study aimed to investigate, for the first time, the components of n-hexane, dichloromethane, and ethyl acetate fractions of Cliona sp. marine sponge collected from the Red Sea, Egypt using UPLC-ESI-MS/MS (Ultra-performance liquid chromatography electrospray ionization tandem mass spectrometry) analysis. The analysis revealed the tentative identification of 23, 16, and 24 compounds from the n-hexane, dichloromethane, and ethyl acetate fractions of Cliona sp., respectively. In addition, the examination of these fractions resulted in the isolation and identification of three sterols and one amino acid. The identification of the isolated compounds was confirmed by 1D and 2D NMR (Nuclear Magnetic Resonance), and MS (Mass spectrometry), and IR (Infrared) spectroscopy. The in vitro cytotoxic, antioxidant, and antimicrobial activities of the total ethanolic extract and its sub-fractions were also evaluated. Interestingly, the ethyl acetate fraction showed potent cytotoxic activity against colon (HCT-116) and human larynx carcinoma (HEP-2) cell lines with IC₅₀ (Half-maximal Inhibitory Concentration) 6.11 ± 0.2 and 12.6 ± 0.9 µg/mL, respectively. However, the dichloromethane fraction showed strong antioxidant activity, with IC₅₀ 75.53 ± 3.41 µg/mL. Notably, the total ethanolic extract showed the strongest antibacterial activity against Staphylococcus aureus and Escherichia coli, with MIC (Minimum Inhibitory Concentration) 62.5 ± 0.82 and 125 ± 0.62 µg/mL, respectively, compared to other fractions. In conclusion, this is the first report on the secondary metabolites content and biological activities of Cliona sp. from the Red Sea, Egypt. It also highlights the need for further research on the most active fractions against various cancer cell lines and resistant bacterial and fungal strains. Cliona sp. extract and its fractions could be a potential source of novel and safe natural drugs with a wide range of medicinal and pharmaceutical applications.

Design, synthesis and molecular docking of novel substituted azepines as inhibitors of PI3K/Akt/TSC2/mTOR signaling pathway in colorectal carcinoma

A series of novel substituted azepines (2-7) was synthesized using both traditional and ultrasonic techniques. The efficiency of the reaction rate and yield was improved by sonication technique. We identified the newly synthesized compounds based on their melting points, elemental analyses, and spectral data. Human cancers are regulated mainly by the phosphatidylinositol 3-kinase/protein kinases B (PI3K/Akt) pathway, and its abnormal activation is linked to carcinogenesis, and angiogenesis. Using in-silico studies, we evaluated the ability of all the novel substituted diazepines and oxazepines to prevent cancer growth and metastasis by targeting the PI3K/Akt signaling pathway. Based on our findings, compounds 4a and 7a were chosen for in-vitro testing as they ranked via molecular docking the highest binding energies of -10.9, -10.3, -10.6, and -10.4 kcal/mol respectively. Compounds 4a and 7a displayed significant cytotoxicity on Caco-2 colorectal cancer cells with IC₅₀ values of 8.445 ± 2.26 and 33.04 ± 2.06 μM, respectively. Additionally, they considerably suppressed the PI3K/Akt proteins and generated reactive oxygen species (ROS), which increased p53 and Bax, decreased Bcl-₂ levels, and arrested the cell cycle at sub-G0/G1 phase. We also observed a remarkable overexpression of the Tuberous Sclerosis Complex 2 (TSC2) gene, an inhibitor of the mammalian target of rapamycin (mTOR). These results showed that compounds 4a and 7a obeyed Lipinski's rule of five and might be potential cancer treatment scaffolds by preventing metastasis and proliferation via blocking the PI3K/Akt/TSC2/m-TOR signaling pathway. This supports our hypothesis that diazepine 4a and oxazepine 7a are promising drug candidates for colorectal cancer.

Bioguided isolation of potential antitumor agents from the aerial parts of cultivated cardoon (Cynara cardunculus var. altilis)

Hepatocellular carcinoma (HCC) is one of the leading causes of mortality worldwide; therefore, searching for an effective treatment for this illness is of great importance. In the present work, in vitro cytotoxic activity of the ethanol extract of the aerial parts of Cynara cardunculus L. against human liver carcinoma cells (Hep G2) was tested. Additionally, the antitumor activity of the extract was confirmed using chemically induced rat liver carcinogenesis with diethylnitrosamine (DEN). Moreover, bioguided fractionation and column chromatographic separation of the active compounds were carried out. The extract of C. cardunculus showed a promising cytotoxic activity according to the protocols of the National Cancer Institute. Bioguided chromatographic separation of the ethanol extract of C. cardunculus led to the isolation of seven secondary metabolites including two sesquiterpene lactones as the principal active components of the methylene chloride soluble fraction, grosheimin (IC₅₀ = 7.49 µg/mL) and cynaropicrin (IC₅₀ = 13.9 µg/mL). The compounds were characterized by different spectroscopic techniques such as EI-MS, IR and NMR. Additionally, in silico analysis of the two active compounds revealed their ability to bind with caspase-3 via hydrogen bonds interactions to initiate apoptosis of cancer cells. The results shed the light on the significance of C. cardunculus as a potential source of antitumor agents.

Anticancer Activity of Thiophene Carboxamide Derivatives as CA-4 Biomimetics: Synthesis, Biological Potency, 3D Spheroid Model, and Molecular Dynamics Simulation

The present study aimed to synthesize thiophene carboxamide derivatives, which are considered biomimetics of the anticancer medication Combretastatin A-4 (CA-4), and compare the similarity in the polar surface area (PSA) between the novel series and CA-4. Our results showed that the PSA of the most synthesized structures was biomimetic to CA-4, and similar chemical and biological properties were observed against Hep3B cancer cell line. Among the synthesized series 2b and 2e compounds were the most active molecules on Hep3B (IC50 = 5.46 and 12.58 µM, respectively). The 3D results revealed that both 2b and 2e structures confuse the surface of Hep3B cancer cell lines' spheroid formation and force these cells to aggregate into a globular-shaped spheroid. The 2b and 2e showed a comparable interaction pattern to that observed for CA-4 and colchicine within the tubulin-colchicine-binding pocket. The thiophene ring, due to holding a high aromaticity character, participated critically in that observed interaction profile and showed additional advanced interactions over CA-4. The 2b and 2e tubulin complexes showed optimal dynamics trajectories within a time scale of 100 ns at 300 K temperature, which asserts their high stability and compactness. Together, these findings revealed the biomimetic role of 2b and 2e compounds in CA-4 in preventing cancer progression.

Design, Synthesis, Anticancer Activity and Molecular Docking of New 1,2,3-Triazole-Based Glycosides Bearing 1,3,4-Thiadiazolyl, Indolyl and Arylacetamide Scaffolds

New 1,3,4-thiadiazole thioglycosides linked to a substituted arylidine system were synthesized via heterocyclization via click 1,3-dipolar cycloaddition. The click strategy was used for the synthesis of new 1,3,4-thiadiazole and 1,2,3-triazole hybrid glycoside-based indolyl systems as novel hybrid molecules by reacting azide derivatives with the corresponding acetylated glycosyl terminal acetylenes. The cytotoxic activities of the compounds were studied against HCT-116 (human colorectal carcinoma) and MCF-7 (human breast adenocarcinoma) cell lines using the MTT assay. The results showed that the key thiadiazolethione compounds, the triazole glycosides linked to p-methoxyarylidine derivatives and the free hydroxyl glycoside had potent activity comparable to the reference drug, doxorubicin, against MCF-7 human cancer cells. Docking simulation studies were performed to check the binding patterns of the synthesized compounds. Enzyme inhibition assay studies were also conducted for the epidermal growth factor receptor (EGFR), and the results explained the activity of a number of derivatives.

Synthesis, Molecular Docking Study, and Cytotoxicity Evaluation of Some Novel 1,3,4-Thiadiazole as Well as 1,3-Thiazole Derivatives Bearing a Pyridine Moiety

Pyridine, 1,3,4-thiadiazole, and 1,3-thiazole derivatives have various biological activities, such as antimicrobial, analgesic, anticonvulsant, and antitubercular, as well as other anticipated biological properties, including anticancer activity. The starting 1-(3-cyano-4,6-dimethyl-2-oxopyridin-1(2H)-yl)-3-phenylthiourea (2) was prepared and reacted with various hydrazonoyl halides 3a–h, α-haloketones 5a–d, 3-chloropentane-2,4-dione 7a and ethyl 2-chloro-3-oxobutanoate 7b, which afforded the 3-aryl-5-substituted 1,3,4-thiadiazoles 4a–h, 3-phenyl-4-arylthiazoles 6a–d and the 4-methyl-3- phenyl-5-substituted thiazoles 8a,b, respectively. The structures of the synthesized products were confirmed by spectral data. All of the compounds also showed remarkable anticancer activity against the cell line of human colon carcinoma (HTC-116) as well as hepatocellular carcinoma (HepG-2) compared with the Harmine as a reference under in vitro condition. 1,3,4-Thiadiazole 4h was found to be most promising and an excellent performer against both cancer cell lines (IC₅₀ = 2.03 ± 0.72 and 2.17 ± 0.83 µM, respectively), better than the reference drug (IC₅₀ = 2.40 ± 0.12 and 2.54 ± 0.82 µM, respectively). In order to check the binding modes of the above thiadiazole derivatives, molecular docking studies were performed that established a binding site with EGFR TK.

Evaluation of the Binding Relationship of the RdRp Enzyme to Novel Thiazole/Acid Hydrazone Hybrids Obtainable through Green Synthetic Procedure

The viral RNA-dependent RNA polymerase (RdRp) complex is used by SARS-CoV-2 for genome replication and transcription, making RdRp an interesting target for developing the antiviral treatment. Hence the current work is concerned with the green synthesis, characterization and docking study with the RdRp enzyme of the series of novel and diverse hydrazones and pyrazoles. 4-Methyl-2-(2-(1-phenylethylidene)hydrazineyl)thiazole-5-carbohydrazide was prepared and then condensed with different carbonyl compounds (aldehydes and ketones either carbocyclic aromatic or heterocyclic) afforded the corresponding hydrazide-hydrazones. The combination of the acid hydrazide with bifunctional reagents such as acetylacetone, β-ketoesters (ethyl acetoacetate and ethyl benzoylacetate) resulted in the formation of pyrazole derivatives. The synthesized compounds were all obtained through grinding method using drops of AcOH. Various analytical and spectral analyses were used to determine the structures of the prepared compounds. Molecular Operating Environment (MOE^®) version 2014.09 was used to estimate interactions between the prepared thiazole/hydrazone hybrids and RdRp obtained from the protein data bank (PDB: 7bv2) using enzyme-ligand docking for all synthesized derivatives and Remdesivir as a reference. Docking results with the RdRp enzyme revealed that the majority of the investigated drugs bind well to the enzyme via various types of interactions in comparison with the reference drug.

Synthesis, Molecular Docking Study, and Cytotoxic Activity against MCF Cells of New Thiazole–Thiophene Scaffolds

Investigating novel compounds that may be useful in designing new, less toxic, selective, and potent breast anticancer agents is still the main challenge for medicinal chemists. Thus, in the present work, acetylthiophene was used as a building block to synthesize a novel series of thiazole-bearing thiophene derivatives. The structures of the synthesized compounds were elucidated based on elemental analysis and spectral measurements. The cytotoxic activities of the synthesized compounds were evaluated against MCF-7 tumor cells and compared to a cisplatin reference drug, and against the LLC-Mk2 normal cell line using the MTT assay, and the results revealed promising activities for compounds 4b and 13a. The active compounds were subjected to molecular modeling using MOE 2019, the pharmacokinetics were studied using SwissADME, and a toxicity radar was obtained from the biological screening data. The results obtained from the computational studies supported the results obtained from the anticancer biological studies.

Synthesis of novel isoxazole-carboxamide derivatives as promising agents for melanoma and targeted nano-emulgel conjugate for improved cellular permeability

BACKGROUND

Cancer is one of the most dangerous and widespread diseases in the world today and it has risen to the position of the leading cause of death around the globe in the last few decades. Due to the inherent resistance of many types of cancer to conventional radiotherapy and chemotherapy, it is vital to develop innovative anticancer medications. Recently, a strategy based on nanotechnology has been used to improve the effectiveness of both old and new cancer drugs.

OBJECTIVES

The present study aimed to design and synthesize a series of phenyl-isoxazole-Carboxamide derivatives, evaluate their anticancer properties, and improve the permeability of potent compounds into cancer cells by using a nano-emulgel strategy.

METHODS

The coupling reaction of aniline derivatives and isoxazole-Carboxylic acid was used to synthesize a series of isoxazole-Carboxamide derivatives. IR, HRMS, 1H-NMR, and 13C-NMR spectroscopy techniques, characterized all the synthesized compounds. The in-vitro cytotoxic evaluation was performed by using the MTS assay against seven cancer cell lines, including hepatocellular carcinoma (Hep3B and HepG2), cervical adenocarcinoma (HeLa), breast carcinoma (MCF-7), melanoma (B16F1), colorectal adenocarcinoma (Caco-2), and colon adenocarcinoma (Colo205), as well as human hepatic stellate (LX-2) in addition to the normal cell line (Hek293T). A nano-emulgel was developed for the most potent compound, using a self-emulsifying technique.

RESULTS

All synthesized compounds were found to have potent to moderate activities against B16F1, Colo205, and HepG2 cancer cell lines. The results revealed that the 2a compound has broad spectrum activity against B16F1, Colo205, HepG2, and HeLa cancer cell lines with an IC₅₀ range of 7.55-40.85 µM. Moreover, compound 2e was the most active compound against B16F1 with an IC₅₀ of 0.079 µM compared with Dox (IC₅₀ = 0.056 µM). Nanoemulgel was used to increase the potency of the 2e molecule against this cancer cell line, and the IC₅₀ was reduced to 0.039 µM. The antifibrotic activities were investigated against the LX-2 cell line, and it was found that our synthesized molecules showed better antifibrotic activities at 1 µM than 5-FU, and the cell viability values were 67 and 95%, respectively.

CONCLUSION

This study suggests that a 2e nano-formalized compound is a potential and promising anti-melanoma agent.

Metabolic Profiling and In Vitro Assessment of the Biological Activities of the Ethyl Acetate Extract of Penicillium chrysogenum “Endozoic of Cliona sp. Marine Sponge” from the Red Sea (Egypt)

Marine sponge-derived endozoic fungi have been gaining increasing importance as promising sources of numerous and unique bioactive compounds. This study investigates the phytochemical profile and biological activities of the ethyl acetate extract of Penicillium chrysogenum derived from Cliona sp. sponge. Thirty-six compounds were tentatively identified from P. chrysogenum ethyl acetate extract along with the kojic acid (KA) isolation. The UPLC-ESI-MS/MS positive ionization mode was used to analyze and identify the extract constituents while 1D and 2D NMR spectroscopy were used for kojic acid (KA) structure confirmation. The antimicrobial, antioxidant, and cytotoxic activities were assessed in vitro. Both the extract and kojic acid showed potent antibacterial activity against Staphylococcus aureus and Pseudomonas aeruginosa with MIC 250 ± 0.82 µg/mL. Interestingly, the extract showed strong antifungal activity against Candida albicans and Cryptococcus neoformans with MIC 93.75 ± 0.55 and 19.53 ± 0.48 µg/mL, respectively. Furthermore, KA showed the same potency against Fusarium oxysporum and Cryptococcus neoformans with MIC 39.06 ± 0.85 and 39.06 ± 0.98 µg/mL, respectively. Ultimately, KA showed strong antioxidant activity with IC₅₀ 33.7 ± 0.8 µg/mL. Moreover, the extract and KA showed strong cytotoxic activity against colon carcinoma (with IC₅₀ 22.6 ± 0.8 and 23.4 ± 1.4 µg/mL, respectively) and human larynx carcinoma (with equal IC₅₀ 30.8 ± 1.3 and ± 2.1 µg/mL, respectively), respectively. The current study represents the first insights into the phytochemical profile and biological properties of P. chrysoenum ethyl acetate extract, which could be a promising source of valuable secondary metabolites with potent biological potentials.

Synthesis and Diuretic Activity of Substituted 1,3,4-Thiadiazoles

1,3,4-Thiadiazole nuclease, a 5-membered heterocyclic ring system containing two nitrogen and one sulfur atoms in addition to carbon atoms, is compound that showed promising results in the process of searching new diuretic agents. In this study, seven 5- and 2-thioate derivatives of 1, 3, 4-thiadiazoles were synthesized by substitution reaction using acetone as solvent and K₂CO₃ as a base. The compounds ware then characterized by using IR and NMR spectroscopy. The diuretic activity of the compounds was evaluated on Swiss albino mice by measuring urine volume, urinary pH, and urinary Na⁺, K⁺, and Cl^-. The result showed increase in urinary excretion of both water and electrolytes. 5-Methyl-substituted derivatives of 1, 3, 4-thiadiazoles showed significant increase in excretion of both water and electrolytes when they are compared to both negative control and 5-amino-substituted derivatives. The highest diuretic activity (0.82) was recorded for para-nitro-substituted benzene ring at 2-thioate group of 5-methyl-1, 3, 4-thiadiazole, while the least (0.56) was recorded for propanethioate group at 2^nd position and amine group at 5^th position of 1, 3, 4-thiadiazole. The finding of the present study showed that all the compounds have diuretic activity and 5-methyl derivatives of 1, 3, 4-thiadiazoles exhibited significant diuretic activity.

New 1,3,4-Thiadiazole Derivatives with Anticancer Activity

We designed and synthesized the 1,3,4-thiadiazole derivatives differing in the structure of the substituents in C2 and C5 positions. The cytotoxic activity of the obtained compounds was then determined in biological studies using MCF-7 and MDA-MB-231 breast cancer cells and normal cell line (fibroblasts). The results showed that in both breast cancer cell lines, the strongest anti-proliferative activity was exerted by 2-(2-trifluorometylophenylamino)-5-(3-methoxyphenyl)-1,3,4-thiadiazole. The IC₅₀ values of this compound against MCF-7 and MDA-MB-231 breast cancer cells were 49.6 µM and 53.4 µM, respectively. Importantly, all new compounds had weaker cytotoxic activity on normal cell line than on breast cancer cell lines. In silico studies demonstrated a possible multitarget mode of action for the synthesized compounds. The most likely mechanism of action for the new compounds is connected with the activities of Caspase 3 and Caspase 8 and activation of BAX proteins.

Pharmacological Evaluation of Novel 1,2,4-triazine Derivatives Containing Thiazole Ring against Hepatocellular Carcinoma

Background:

New 6-hydroxy-5-(p-hydroxybenzylidene)-3-phenyl-2- [(5-pchlorophenyl)- 1,3-thiazol-2-yl]-1, 2, 4-triazine derivatives containing a thiazole ring were synthesised as potential antitumor agents.

Methods:

Cytotoxicity of compounds (3) and (4) was evaluated in human hepatocellular carcinoma (HCC) cell lines (HepG2); compound (3) showed more cytotoxicity (IC50=9.0μg/ml) than compound (4) (IC50=18.40μg/ml) using doxorubicin as standard. The degree of toxicity of compound (3) was assessed by the LD50 with its anticancer performance by suppressing tumor angiogenesis against diethylnitrosamine (DENA) induced hepatocellular carcinoma (HCC) in male rat model.

Results :

Carcinogenic rats showed a significant increase in markers of angiogenesis, tumour growth, and liver function tests and malondialdehyde level coupled with reduced hepatic glutathione level and caspase-3 activity. The distribution of compound (3) to animals after the development of HCC improved biochemical alterations from a DENA chemical carcinogen that is confirmed by hepatic histopathology.

Conclusion:

Compound 3 perhaps utilized as a strong applicant for newly therapeutic protocols against hepatocarcinogenesis by controlling tumor angiogenesis and renovating the activity of hepatic marker enzymes in addition to reversing the oxidant-antioxidant imbalance in corporation with amelioration of histopathology. While the trial supports the use of compound 3 for improved HCC outcome and the toxicity and side effects should be considered.

Three-Component Synthesis of Some New Coumarin Derivatives as Anticancer Agents

A three-component reaction for the synthesis of novel 3-heteroaryl-coumarin utilizing acetylcoumarin synthon under ultrasonic irradiation was developed using chitosan-grafted poly(vinylpyridine) as an eco-friendly catalyst. The process is a simple, facile, efficient procedure for the preparation of compounds displaying a thiazole ring linked to coumarin moiety. Moreover, all the products were evaluated for their anticancer activities against HEPG2-1. The results revealed that three new compounds showed promising anticancer activities.

Synthesis and Biological Evaluation of Thiazolyl-Ethylidene Hydrazino-Thiazole Derivatives: A Novel Heterocyclic System

The reaction of 2-(1-(2-(2-(4-methoxybenzylidene)hydrazinyl)-4-methylthiazol-5-yl)ethylidene)hydrazinecarbothioamide with a range of hydrazonoyl chlorides and α-halo-compounds yielded three new series of thiazole derivatives. Chemical and physical techniques were used to analyze all newly prepared derivatives (1H-NMR, 13C-NMR, FT-IR and mass spectrometry). The potential antimicrobial and anticancer properties of the synthesized derivatives were investigated using various in vitro biological experiments. Most of the thiazole compounds tested were effective against Gram-positive and Gram-negative bacteria. In addition, a minimum inhibition concentration was determined for the antibiotic properties of the most active produced substances. The cytotoxic activities were tested on HepG-2 (liver carcinoma), HCT-116 (colorectal carcinoma) and MDA-MB-231 (breast carcinoma) cell lines in comparison with cisplatin reference drug and using colorimetric MTT assay. The results detected that compound 10c was the most potent against the three tested cell lines. Interestingly, when the tested compounds were evaluated for their toxicity against normal (MRC-5) cells, they exhibited low toxic effects indicating the safe use of most of them that may require further in vivo and pharmacological studies.

New nematogenic conical-shaped supramolecular H-bonded complexes for solar energy investigations

New conical-shaped geometrical supramolecular H-bonded liquid crystal complexes were formed through 1:2 intermolecular interactions of H-bonding between flexible core (adipic acid, A) and lateral chloro-substituted azopyridines (Bn). The chains of the terminally alkoxy substituted base (n) were changed between 8 and 16 carbons. Mesomorphic and optical examinations of the prepared complexes were measured via differential scanning calorimetry (DSC) and polarizing optical microscopy (POM). Fourier-transform infrared spectroscopy (FT-IR) was used to confirm the Fermi bands of the H- bonding interactions. Induced nematogenic mesophases that cover the whole lengths of alkoxy-chains were detected. The non-linear geometries of the designed supramolecular complexes were also confirmed via Density functional theory (DFT) calculations. It was found that the length of terminal alkoxy chain of the base moiety highly affects the geometrical structure of the investigated complexes. Moreover, it increases the thermodynamic energy and influences the geometrical parameters. The electrical properties of each of the acid component (A), the base (B16) and their 1:2 complex (A/2B16) were evaluated using the Keithley measurement-source unit. The optical properties studies showed that the influences in the optical absorption and the reduction of the energy gap of the complex compared to its individual components made the resulted supramolecular H-bonded complex soft material suitable for solar energy investigations.

Preparation of New Spiropyrazole, Pyrazole and Hydantoin Derivatives and Investigation of Their Antioxidant and Antibacterial Activities

In this study, the synthesis of new spiropyrazoles, pyrazole and hydantoin heterocycles is reported by three component reactions of parabanic acids, hydrazine derivatives, and phenacyl bromides in the presence of triphenylphosphine as a nucleophile and triethylamine as a base in good to high yields (69-91 %). Evaluation of the synthesized compounds revealed a good to excellent antioxidant activities (37.6-96.2 %) using DPPH inhibitory potency. Among these compounds, hydantoin derivatives displayed higher antioxidant activities (93.7-96.2 %) comparing with spiropyrazoles and pyrazoles. The obtained results showed that Cl and Br substituents on the phenyl ring increased antioxidant activities of the related heterocycles. The antibacterial activities of the synthesized compounds were examined against two Gram-negative (Escherichia coli and Pseudomonas aeruginosa) and two Gram-positive (Staphylococcus aureus and Bacillus subtilis) bacteria. Among the synthesized heterocycles, 2-[1,3-dimethyl-2,5-dioxo-4-(2-oxo-2-phenylethyl)imidazolidin-4-yl]hydrazine-1-carbothioamide exhibited the excellent antibacterial activity against both Gram-positive and Gram-negative bacteria.

Inhibitory activities of bipyrazoles: a patent review

Introduction: Bipyrazole is constituted from two pyrazole units either in their fully aromatic or partially hydrogenated forms. Pyrazoles are widely available in pharmaceutical and agrochemical products. Some pyrazoles are essential parts of commercial drugs in the market. This inspired us to collect the pharmacological activities of bipyrazoles that have potential therapeutic behaviors in several biological aspects but none of them were included in commercial drugs.Areas covered: This review covers all biological and pharmacological potentials of bipyrazole derivatives during 2010-2021. The topics of this review comprised anticancer, antioxidant, anti-inflammatory, antimicrobial, antitubercular, antimalarial, insecticidal activities as well as enzymatic inhibitions.Expert opinion: Bipyrazoles demonstrated a wide array of potent activities against various diseases such as anticancer, antitubercular, anti-inflammatory, and antimicrobial activities. Those are of great benefits for medicinal researchers to develop promising building blocks of bipyrazoles for treatment of diseases. The SAR studies showed that metallated bipyrazoles had better biological activities than bipyrazole ligands. For example, gold(III) and iridium(II) complexes of bipyrazoles were proved to be anticancer agents, and copper(I) as well as silver(I) complexes had excellent antibacterial activities. Several bipyrazoles were reported as antimalarial inhibitors better than chloroquine, the possible COVID-19 drug.

Microwave-Assisted One Pot Three-Component Synthesis of Novel Bioactive Thiazolyl-Pyridazinediones as Potential Antimicrobial Agents against Antibiotic-Resistant Bacteria

Pyridazine and thiazole derivatives have various biological activities such as antimicrobial, analgesic, anticancer, anticonvulsant, antitubercular and other anticipated biological properties. Chitosan can be used as heterogeneous phase transfer basic biocatalyst in heterocyclic syntheses. Novel 1-thiazolyl-pyridazinedione derivatives were prepared via multicomponent synthesis under microwave irradiation as ecofriendly energy source and using the eco-friendly naturally occurring chitosan basic catalyst with high/efficient yields and short reaction time. All the prepared compounds were fully characterized by spectroscopic methods, and their in vitro biological activities were investigated. The obtained results were compared with those of standard antibacterial/antifungal agents. DFT calculations and molecular docking studies were used to investigate the electronic properties and molecular interactions with specific microbial receptors.

Synthesis and Cytotoxic Activity Study of Novel 2-(Aryldiazenyl)-3-methyl-1H-benzo[g]indole Derivatives

A novel series of 2-(aryldiazenyl)-3-methyl-1H-benzo[g]indole derivatives (3a-f) were prepared through the cyclization of the corresponding arylamidrazones, employing polyphosphoric acid (PPA) as a cyclizing agent. All of the compounds (3a-f) were characterized using ¹H NMR, ¹³C NMR, MS, elemental analysis, and melting point techniques. The synthesized compounds were evaluated for cytotoxic activity against diverse human cancer cell lines by the National Cancer Institute. While all of the screened compounds were found to be cytotoxic at a 10 µM concentration, two of them (2c) and (3c) were subjected to five dose screens and showed a significant cytotoxicity and selectivity.

Echinops taeckholmiana Amin: Optimization of a Tissue Culture Protocol, Biological Evaluation, and Chemical Profiling Using GC and LC-MS

There have been no reports published on the rare Echinops taeckholmiana growing wildly in Egypt. So, this study aimed to preserve it through method optimization of in vitro seed germination, besides callus formation from induced seedlings. Chemical profiling using gas chromatography-mass spectrometry (GC-MS) analysis of the n-hexane fraction afforded 29 identified components, mainly fatty acids esters, sesquiterpenes, triterpenes, one thiophene, and bis(2-ethylhexyl) phthalate. Ultra-performance liquid chromatography-electron spray ionization/tandem mass spectrometry (UPLC-ESI/MS-MS) analysis of total alcoholic root and induced calli extracts resulted in 68 metabolites. Taraxeryl acetate, β-sitosterol, stigmasterol-3β-d-glucoside, and 1,1,1-kestopentaose were identified from the defatted root extract, which inhibited α-amylase (IC50 54.6 μg/mL) and α-glucosidase (60.4 μg/mL) enzymes compared with acarbose (IC50 values of 30.57 and 34.71 μg/mL, respectively). Moreover, it showed moderate activity against HepG2 (IC50 31.1 ± 1.4 μg/mL) and no activity against M-NFS-60 cell lines compared to cisplatin (IC50 3.25 ± 1.4 and 8.37 ± 0.25, respectively).

Cytotoxic Properties of 1,3,4-Thiadiazole Derivatives-A Review

During recent years, small molecules containing five-member heterocyclic moieties have become the subject of considerable growing interest for designing new antitumor agents. One of them is 1,3,4-thiadiazole. This study is an attempt to collect the 1,3,4-thiadiazole and its derivatives, which can be considered as potential anticancer agents, reported in the literature in the last ten years.

UPLC-ESI-MS/MS Profile and Antioxidant, Cytotoxic, Antidiabetic, and Antiobesity Activities of the Aqueous Extracts of Three Different Hibiscus Species

The aqueous extracts of Hibiscus calyphyllus (HcA), Hibiscus micranthus (HmA), and Hibiscus deflersii (HdA) growing in Saudi Arabia did not receive enough attention in phytochemical and biological studies. This inspired the authors to investigate the phytochemicals of these extracts for the first time using UPLC-ESI-MS/MS in negative and positive ionization modes. The analysis afforded the tentative identification of 103 compounds including phenolic compounds, flavonoids, and anthocyanins. Moreover, in vitro evaluations of their cytotoxic, antioxidant, antidiabetic, and antiobesity activities were carried out. The results showed that aqueous extract of Hibiscus calyphyllus had the highest activity as an antioxidant agent (SC50 = 111 ± 1.5 μg/mL) compared with ascorbic acid (SC50 = 14.2 ± 0.5 μg/mL). MTT assay was used to evaluate cytotoxic activity compared to cisplatin. Hibiscus deflersii showed the most potent cytotoxic effect against A-549 (human lung carcinoma) with IC50 = 50 ± 5.1 μg/mL, and Hibiscus micranthus showed a close effect with IC50 = 60.4 ± 1.7 μg/mL. Hibiscus micranthus showed the most potent effect on HCT-116 (human colon carcinoma) with IC50 = 56 ± 1.9 μg/mL compared with cisplatin (IC50 = 7.53 ± 3.8 μg/mL). HcA and HdA extracts showed weak cytotoxic activity against A-549 and HCT-116 cell lines compared to the other extracts. Eventually, Hibiscus deflersii showed astonishing antidiabetic (IC50 = 56 ± 1.9 μg/mL) and antiobesity (IC50 = 95.45 ± 1.9 μg/mL) activities using in vitro α-amylase inhibitory assay (compared with acarbose (IC50 = 34.71 ± 0.7 μg/mL)) and pancreatic lipase inhibitory assay (compared with orlistat (IC50 = 23.8 ± 0.7 μg/mL)), respectively. In conclusion, these findings are regarded as the first vision of the phytochemical constituents and biological activities of different Hibiscus aqueous extracts. Hibiscus deflersii aqueous extract might be a hopeful origin of functional constituents with anticancer (on A-549 cell line), antidiabetic, and antiobesity activities. It might be a natural alternative remedy and nutritional policy for diabetes and obesity treatment without negative side effects. Isolation of the bioactive phytochemicals from the aqueous extracts of aerial parts of Hibiscus calyphyllus, Hibiscus micranthus, and Hibiscus deflersii and estimation of their biological effects are recommended in further studies.

Novel molecular discovery of promising amidine-based thiazole analogues as potent dual Matrix Metalloproteinase-2 and 9 inhibitors: Anticancer activity data with prominent cell cycle arrest and DNA fragmentation analysis effects

Thiazole derivatives are known to possess various biological activities such as antiparasitic, antifungal, antimicrobial and antiproliferative activities. Matrix metalloproteinases (MMPs) are important protease target involved in tumor progression including angiogenesis, tissue invasion, and migration. Therefore, MMPs have also been reported as potential diagnostic and prognostic biomarkers in many types of cancer. Herein, new aryl thiazoles were synthesized and evaluated for their anticancer effects on a panel of cancer cell lines including the invasive MDA-MB-231 line. Some of these compounds showed IC₅₀ values in the submicromolar range in anti-proliferative assays. In order to examine the relationship between their anticancer activity and MMPs targets, the compounds were evaluated for their inhibitory effects on MMP-2 and 9. That data obtained revealed that most of these compounds were potent dual MMP-2/9 inhibitors at nanomolar concentrations. Among these, 2-(1-(2-(2-((E)-4-iodobenzylidene)hydrazineyl)-4-methylthiazol-5-yl)ethylidene)hydrazine-1-carboximidamide (4a) was the most potent non-selective dual MMP-2/9 inhibitor with inhibitory concentrations of 56 and 38 nM respectively. When compound 4a was tested in an MDA-MB-231, HCT-116, MCF-7 model, it effectively inhibited tumor growth, strongly induced cancer cell apoptosis, inhibit cell migration, and suppressed cell cycle progression leading to DNA fragmentation. Taken together, the results of our studies indicate that the newly discovered thiazole-based MMP-2/9 inhibitors have significant potential for anticancer treatment.

One-Pot Synthesis of Novel Thiazoles as Potential Anti-Cancer Agents

Background

Thiazole and thiosemicarbazone derivatives are known to have potential anticancer activity with a mechanism of action related to inhibition of matrix metallo-proteinases, kinases and anti-apoptotic BCL2 family proteins.

Materials and Methods

A novel three series of 5-(1-(2-(thiazol-2-yl)hydrazono)ethyl)thiazole derivatives were prepared in a one-pot three-component reaction using 2-(2-benzylidene hydrazinyl)-4-methylthiazole as a starting precursor. MS, IR, ¹H-NMR and ¹³C-NMR were used to elucidate the structures of the synthesized compounds. Most of the synthesized products were evaluated for their in vitro anticancer screening against HCT-116, HT-29 and HepG2 using the MTT colorimetric assay.

Results

The results indicated that compounds 4c, 4d and 8c showed growth inhibition activity against HCT-116 with IC₅₀ values of 3.80 ± 0.80, 3.65 ± 0.90 and 3.16 ± 0.90 μM, respectively, compared to harmine (IC₅₀ = 2.40 ± 0.12 μM) and cisplatin (IC₅₀ = 5.18 ± 0.94 μM) reference drugs. Also, compounds 8c, 4d and 4c showed promising IC₅₀ values of 3.47 ± 0.79, 4.13 ± 0.51 and 7.24 ± 0.62 μM, respectively, against the more resistant human colorectal cancer (HT-29) cell line compared with harmine (IC₅₀ = 4.59 ± 0.67 μM) and cisplatin (IC₅₀ = 11.68 ± 1.54 μM). On the other hand, compounds 4d, 4c, 8c and 11c were the most active (IC₅₀ values of 2.31± 0.43, 2.94 ± 0.62, 4.57 ± 0.85 and 9.86 ± 0.78 μM, respectively) against the hepatocellular carcinoma (HepG2) cell line compared with harmine (IC₅₀ = 2.54 ± 0.82 μM) and cisplatin (IC₅₀ = 41 ± 0.63 μM). The study also suggested that the mechanism of the anticancer action exerted by the most active compounds (4c, 4d and 8c) inside HCT-116 cells was apoptosis through the Bcl-2 family.

Conclusion

Thiazole scaffolds 4c, 4d and 8c showed anticancer activities in the micromolar range and are appropriate as a candidate for cancer treatment.

Facile synthesis and antiproliferative activity of new 3-cyanopyridines

Background

Pyridines have been reported to possess various pharmacological activities.

Results

Sodium 3-oxo-3-(2-oxo-2H-chromen-3-yl)prop-1-en-1-olate (2) and sodium 3-oxo-3-(3-oxo-3H-benzo[f]chromen-2-yl)prop-1-en-1-olate (7) were prepared and reacted with 2-cyano-N'-(1-aryl(heteryl)ethylidene)acetohydrazides 3a-d to produce 2-oxo-1,2-dihydropyridine-3-carbonitrile derivatives 5a-d and 9a-d, respectively, in good yields. Also, 3a-d reacted with sodium (2-oxocyclopentylidene)methanolate (11a) or sodium (2-oxocyclohexylidene) methanolate (11b) to yield 2-oxo-tetrahydro-1H-cyclopenta[b]pyridine-3-carbonitriles 13a-d and 2-oxo-hexahydroquinoline-3-carbonitriles 13e-h, respectively. The mechanisms that account for the formation of the products are discussed. Additionally, the structures of all the newly synthesized products are confirmed, based on elemental analysis and spectral data. Several of the newly synthesized compounds are evaluated for their antitumor activity against HEPG2 and their structure activity relationship (SAR) was studied.

Conclusions

The results revealed that the pyridine derivatives 5c and 5d (IC₅₀ = 1.46, 7.08 µM, respectively) have promising antitumor activity against liver carcinoma cell line (HEPG2), compared to the reference drug, doxorubicin.