New imidazole-2-thiones linked to acenaphythylenone as dual DNA intercalators and topoisomerase II inhibitors: structural optimization, docking, and apoptosis studies

In this article, a new series of 2-((3,5-disubstituted-2-thioxo-imidazol-1-yl)imino)acenaphthylen-1(2H)-ones were synthesized. Imidazole-2-thione with acenaphthylen-one gave a hybrid scaffold that integrated key structural elements essential for DNA damage via direct DNA intercalation and inhibition of the topoisomerase II enzyme. All the synthesized compounds were screened to detect their DNA damage using a terbium fluorescent probe. Results demonstrated that 4-phenyl-imidazoles 5b and 5e in addition to 4-(4-chlorophenyl)imidazoles 5h and 5j would induce detectable potent damage in ctDNA. The four most potent compounds as DNA intercalators were further evaluated for their antiproliferative activity against HepG2, MCF-7 and HCT-116 utilizing the MTT assay. The highest anticancer activity was recorded with compounds 5b and 5h against the breast cancer cell line MCF-7 which were 1.5- and 3- folds more active than doxorubicin, respectively. Therefore, imidazole-2-thione tethered acenaphthylenone derivatives can be considered as promising scaffold for the development of effective dual DNA intercalators and topoisomerase II inhibitors.

Synthesis and Antiproliferative Potential of Thiazole and 4-Thiazolidinone Containing Motifs as Dual Inhibitors of EGFR and BRAFV600E

Thiazole and thiazolidinone recur in a wide range of biologically active compounds that reach different targets within the context of tumors and represent a promising starting point to access potential candidates for treating metastatic cancer. Therefore, searching for new lead compounds that show the highest anticancer potency with the fewest adverse effects is a major drug-discovery challenge. Because the thiazole ring is present in dasatinib, which is currently used in anticancer therapy, it is important to highlight the ring. In this study, cycloalkylidenehydrazinecarbothioamides (cyclopentyl, cyclohexyl, cyclooctyl, dihydronapthalenylidene, flurine-9-ylidene, and indolinonyl) reacted with 2-bromoacetophenone and diethylacetylenedicarboxylate to yield thiazole and 4-thiazolidinone derivatives. The structure of the products was confirmed by using infrared (IR) spectroscopy, nuclear magnetic resonance (NMR) spectroscopy, mass spectrometry, and single-crystal X-ray analyses. The antiproliferative activity of the newly synthesized compounds was evaluated. The most effective inhibitory compounds were further tested in vitro against both epidermal growth factor receptor (EGFR) and B-Raf proto-oncogene, serine/threonine kinase (BRAFV600E) targets. Additionally, molecular docking analysis examined how these molecules bind to the active sites of EGFR and BRAFV600E.

Recent synthetic strategies of spiro-azetidin-2-one, -pyrrolidine, -indol(one) and -pyran derivatives-a review

Spiro-heterocycles have received special attention in medicinal chemistry because of their promising biological activity. Over the years, many synthetic methodologies have been established for the construction of spirocyclic compounds. Spiro heterocycles such as spiro-azetidin-2-one, -pyrrolidine, -indol(one) and -pyran derivatives have been found to exhibit diversified biological and pharmacological activity in addition to their therapeutic properties. In view of these facts, we decided in this review to present representative synthetic approaches of the aforementioned spiro heterocycles, especially in the past 20 years.

Synthesis of bis-thiohydantoin derivatives as an antiproliferative agents targeting EGFR inhibitory pathway

(R)/(S)-the two enantiomers of 3-substituted-1-[2-(5)-3-substituted-4-benzyl-5-oxo-4-phenyl-2-thioxoimid-azolidin-1-yl]ethyl/propyl-5-benzyl-5-phenyl-2-thioxoimidazolidin-4-ones were formed during the diastereoselective reaction between N,N″-1,ω-alkanediylbis[N'-organylthiourea] derivatives and 2,3-diphenylcyclopropenone in refluxing ethanol. The structures of the isolated compounds were confirmed by NMR, IR, mass spectra and elemental analyses. Moreover, single-crystal X-ray structure analysis was also used to elucidate the structure of the isolated compounds. The mechanism describes the reaction was also discussed. The tested compounds showed EGFR inhibitory activity with IC₅₀ values ranging from 90 to 178 nM in comparison to the erlotinib as a reference with IC₅₀ value of 70 nM. Compound 4c (R = allyl, n = 3) was found as the most potent antiproliferative, had the highest inhibitory effect on EGFR with an IC₅₀ value of 90 nM, compared to erlotinib's IC₅₀ value of 70 nM. The second and third-most active compounds were 4e (R = phenyl, n = 3) and 4d (R = ethyl, n = 3) and with IC₅₀ values of 107 nM and 128 nM. These findings imply that the compounds tested had a significant antiproliferative effect as well as the ability to act as an EGFR inhibitor. Docking studies showed that compound 4c showed high affinity to EGFR based on its docking score (S; kcal/mol) within five test compounds.

Novel quinoline/thiazinan-4-one hybrids; design, synthesis, and molecular docking studies as potential anti-bacterial candidates against MRSA

In an attempt to develop effective and safe antibacterial agents, we synthesized novel thiazinanones by combining the quinolone scaffold and the 1,3-thiazinan-4-one group by reaction between ((4-hydroxy-2-oxo-1,2-dihydroquinolin-3-yl)methylene)hydrazinecarbothioamides and 2,3-diphenylcycloprop-2-enone in refluxing ethanol in the presence of triethyl amine as a catalyst. The structure of the synthesized compounds was characterized by spectral data and elemental analysis, IR, MS, ¹H and ¹³C NMR spectroscopy which showed two doublet signals for CH-5 and CH-6 and four sharp singlets for the protons of thiazinane NH, CH[double bond, length as m-dash]N, quinolone NH and OH, respectively. Also, the ¹³C NMR spectrum clearly showed the presence of two quaternary carbon atoms which were assigned to thiazinanone-C-5 and C-6. All the 1,3-thiazinan-4-one/quinolone hybrids were screened for antibacterial activity. Compounds 7a, 7e and 7g showed broad spectrum antibacterial activity against most of the tested strains either G +ve or G -ve. Compound 7e is the most potent antibacterial agent against MRSA with the minimum inhibitory concentration against MRSA found to be 48 μg mL^-1 compared to the drug ciprofloxacin (96 μg mL^-1). Additionally, a molecular docking study was performed to understand the molecular interaction and binding mode of the compounds on the active site of S. aureus Murb protein. In silico docking assisted data strongly correlated with the experimental approach of antibacterial activity against MRSA.

A Novel P@SiO2 Nano-Composite as Effective Adsorbent to Remove Methylene Blue Dye from Aqueous Media

This work aims to prepare a novel phosphate-embedded silica nanoparticles (P@SiO₂) nanocomposite as an effective adsorbent through a hydrothermal route. Firstly, a mixed solution of sodium silicate and sodium phosphate was passed through a strong acidic resin to convert it into hydrogen form. After that, the resultant solution was hydrothermally treated to yield P@SiO₂ nanocomposite. Using kinetic studies, methylene blue (MB) dye was selected to study the removal behavior of the P@SiO₂ nanocomposite. The obtained composite was characterized using several advanced techniques. The experimental results showed rapid kinetic adsorption where the equilibrium was reached within 100 s, and the pseudo-second-order fitted well with experimental data. Moreover, according to Langmuir, one gram of P@SiO₂ nanocomposite can remove 76.92 mg of the methylene blue dye. The thermodynamic studies showed that the adsorption process was spontaneous, exothermic, and ordered at the solid/solution interface. Finally, the results indicated that the presence of NaCl did not impact the adsorption behavior of MB dye. Due to the significant efficiency and promising properties of the prepared P@SiO₂ nanocomposite, it could be used as an effective adsorbent material to remove various cationic forms of pollutants from aqueous solutions in future works.

Design and synthesis of new thiazolidinone/uracil derivatives as antiproliferative agents targeting EGFR and/or BRAFV600E

Thiourea derivatives of uracil were efficiently synthesized via the reaction of 5-aminouracil with isothiocyanates. Then, we prepared uracil-containing thiazoles via condensation of thioureas with diethyl/dimethyl acetylenedicarboxylates. The structures of the products were confirmed by a combination of spectral techniques including infra-red (IR), nuclear magnetic resonance (NMR), mass spectrometry (MS) and elemental analyses. A rationale for the formation of the products is presented. The newly synthesized compounds were evaluated for their in vitro antiproliferative activity against four cancer cell lines. The compounds tested showed promising antiproliferative activity, with GI₅₀ values ranging from 1.10 µM to 10.00 µM. Compounds 3c, 5b, 5c, 5h, 5i, and 5j were the most potent derivatives, with GI₅₀ values ranging from 1.10 µM to 1.80 µM. Compound 5b showed potent inhibitory activity against EGFR and BRAF^V600E with IC₅₀ of 91 ± 07 and 93 ± 08 nM, respectively, indicating that this compound could serve as a dual inhibitor of EGFR and BRAF^V600E with promising antiproliferative properties. Docking computations revealed the great potency of compounds 5b and 5j towards EGFR and BRAF^V600E with docking scores of -8.3 and -9.7 kcal/mol and -8.2 and -9.3 kcal/mol, respectively.

Potential protective effect of 3,3'-methylenebis(1-ethyl-4-hydroxyquinolin-2(1H)-one) against bleomycin-induced lung injury in male albino rat via modulation of Nrf2 pathway: biochemical, histological, and immunohistochemical study

Acute lung injury is a serious condition accounting for the majority of acute respiratory failure. Bleomycin (BLM) is an antibiotic that was first described as a chemotherapeutic agent. 3,3'-methylenebis(1-ethyl-4-hydroxyquinolin-2(1H)-one) was reported to have anti-inflammatory, anti-apoptotic, and anti-oxidative properties. The current work aimed to assess the possible protective effects and the mechanism of protection of 3,3'-methylenebis-(1-ethyl-4-hydroxyquinolin-2(1H)-one) on BLM-induced lung injury in addition to the effect and underlying mechanisms of nuclear factor-erythroid-related factor 2 pathway against this injury. Rats were equally divided into four groups: control group, BLM group, 1-ethyl-4-hydroxyquinolin-2(1H)-one-treated group, and BLM with 1-ethyl-4-hydroxyquinolin-2(1H)-one-treated group. At the end of the work, the blood samples were proceeded for biochemical study. Lung specimens were obtained for biochemical, histological, and immunohistochemical study. The results exhibited a significant increase in both malondialdehyde and tumor necrotic factor-α with a significant decrease in glutathione, superoxide dismutase, IL 10, surfactant protein A, and nuclear factor erythroid 2-related factor 2 in BLM group. The lung histological results showed various morphological changes in the form of disturbed architecture, inflammatory cell infiltration, and intraluminal debris. This group also displayed a significant increase in the mean surface area fraction of anti-cleaved caspase 3, while group IV exhibited amelioration in the previously mentioned parameters and histological alternations that were induced by BLM. It could be concluded that 3,3'-methylenebis(1-ethyl-4-hydroxyquinolin-2(1H)-one) has anti-oxidative, anti-inflammatory, and anti-apoptotic protective effects against BLM-induced lung injury.

Metal complexes of thiosemicarbazones derived by 2-quinolones with Cu(I), Cu(II) and Ni(II); Identification by NMR, IR, ESI mass spectra and in silico approach as potential tools against SARS-CoV-2

Substituted thiosemicarbazones derived by 2-quinolone were synthesized to investigate their complexation capability towards Cu(I), Cu(II) and Ni(II) salts. The structure of the complexes was established by ESI, IR and NMR spectra in addition to elemental analyses. Monodetate Cu(I) quinoloyl-substituted ligands were observed, whereas Ni(II) and Cu(II) formed bidentate-thiosemicarbazone derived by 2-quinolones. Subsequently, molecular docking was used to evaluate each analog's binding affinity as well as the inhibition constant (ki) to RdRp complex of SARS-CoV-2. Docking results supported the ability of the tested complexes that potentially inhibit the RdRp of SARSCov-2 show binding energy higher than their corresponding ligands. Additionally, ADMET prediction revealed that some compounds stratify to Lipinski's rule, indicating a good oral absorption, high bioavailability good permeability, and transport via biological membranes. Therefore, these metals-based complexes are suggested to be potentially good candidates as anti-covid agents.

Copper Complexes of 1,4-Naphthoquinone Containing Thiosemicarbazide and Triphenylphosphine Oxide Moieties; Synthesis and Identification by NMR, IR, Mass, UV Spectra, and DFT Calculations

New 1,4-naphthoquinone derived by triphenylphosphaneylidene (Ph₃P) and N-substituted-hydrazine-1-carbothioamides were obtained during a one-pot reaction of 2,3-dichloro-1,4-naphthoquinone with thiosemicarbazides, Ph₃P and in the presence of triethyl amine (Et₃N) as a catalyst. The structure of the ligands was established by ESI, IR, and NMR spectra, in addition to elemental analyses and X-ray structure analysis. On subjecting the newly prepared ligands with CuCl₂ and Ph₃P, autoxidation occurs, and (E)-(2-(1,4-dioxo-3-(triphenyl phosphanylidene)-3,4-dihydronaphthalen-2(1H)-ylidene)carbamothioyl)hydrazinyl)-((triphenylphosphanyl)oxy)copper derivatives were formed in very good yields. The structure of the obtained complexes was proved by ESI, IR, NMR, and UV spectra, in addition to elemental analyses and theoretical calculations.

High-Pressure Metal-Free Catalyzed One-Pot Two-Component Synthetic Approach for New 5-Arylazopyrazolo[3,4-b]Pyridine Derivatives

An appropriate and efficient Q-tube-assisted ammonium acetate-mediated protocol for the assembly of the hitherto unreported 5-arylazopyrazolo[3,4-b]pyridines was demonstrated. This methodology comprises the cyclocondensation reaction of 5-amino-2-phenyl-4H-pyrazol-3-one with an assortment of arylhydrazonals in an NH4OAc/AcOH buffer solution operating a Q-tube reactor. This versatile protocol exhibited several outstanding merits: easy work-up, mild conditions, scalability, broad substrate scope, safety (the Q-tube kit is simply for pressing and sealing), and a high atom economy. Consequently, performing such reactions under elevated pressures and utilizing the Q-tube reactor seemed preferable for achieving the required products in comparison to the conventional conditions. Diverse spectroscopic methods and X-ray single-crystal techniques were applied to confirm the proposed structure of the targeted compounds.

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.

Azides in the Synthesis of Various Heterocycles

In this review, we focus on some interesting and recent examples of various applications of organic azides such as their intermolecular or intramolecular, under thermal, catalyzed, or noncatalyzed reaction conditions. The aforementioned reactions in the aim to prepare basic five-, six-, organometallic heterocyclic-membered systems and/or their fused analogs. This review article also provides a report on the developed methods describing the synthesis of various heterocycles from organic azides, especially those reported in recent papers (till 2020). At the outset, this review groups the synthetic methods of organic azides into different categories. Secondly, the review deals with the functionality of the azido group in chemical reactions. This is followed by a major section on the following: (1) the synthetic tools of various heterocycles from the corresponding organic azides by one-pot domino reaction; (2) the utility of the chosen catalysts in the chemoselectivity favoring C−H and C-N bonds; (3) one-pot procedures (i.e., Ugi four-component reaction); (4) nucleophilic addition, such as Aza-Michael addition; (5) cycloaddition reactions, such as [3+2] cycloaddition; (6) mixed addition/cyclization/oxygen; and (7) insertion reaction of C-H amination. The review also includes the synthetic procedures of fused heterocycles, such as quinazoline derivatives and organometal heterocycles (i.e., phosphorus-, boron- and aluminum-containing heterocycles). Due to many references that have dealt with the reactions of azides in heterocyclic synthesis (currently more than 32,000), we selected according to generality and timeliness. This is considered a recent review that focuses on selected interesting examples of various heterocycles from the mechanistic aspects of organic azides.

Recent progress in the applications of silica-based nanoparticles

Functionalized silica nanoparticles (SiO2 NPs) have attracted great attention due to their promising distinctive, versatile, and privileged physiochemical characteristics. These enhanced properties make this type of functionalized nanoparticles particularly appropriate for different applications. A lack of reviews that summarizes the fabrications of such nanomaterials and their different applications in the same work has been observed in the literature. Therefore, in this work, we will discuss the recent signs of progress in the fabrication of functionalized silica nanoparticles and their attractive applications that have been extensively highlighted (advanced catalysis, drug-delivery, biomedical applications, environmental remediation applications, and wastewater treatment). These applications have been selected for demonstrating the role of the surface modification step on the various properties of the silica surface. In addition, the current challenges in the applications of functionalized silica nanoparticles and corresponding strategies to discuss these issues and future perspectives for additional improvement have been addressed.

Efficient Synthesis of Various Substituted (Thio)Ureas, Semicarbazides, Thiosemicarbazides, Thiazolidones, and Oxadiazole Derived from [2.2]Paracyclophane

The strategies of the syntheses of various (thio)ureas, semicarbazides, thiosemicarbazides, thiazolidones, and oxadiazole derived from the [2.2]paracyclophane molecule are achieved starting with 4-(2.2]paracyclophanyl)isocyanate. The structures of the obtained products were elucidated by NMR, mass spectrometry, and infrared (IR) spectroscopy in addition to high-resolution mass spectrometry (HRMS). X-ray structure analysis was also used to prove the assigned structure.

Review of the Recent Advances in Electrospun Nanofibers Applications in Water Purification

Recently, nanofibers have come to be considered one of the sustainable routes with enormous applicability in different fields, such as wastewater treatment. Electrospun nanofibers can be fabricated from various materials, such as synthetic and natural polymers, and contribute to the synthesis of novel nanomaterials and nanocomposites. Therefore, they have promising properties, such as an interconnected porous structure, light weight, high porosity, and large surface area, and are easily modified with other polymeric materials or nanomaterials to enhance their suitability for specific applications. As such, this review surveys recent progress made in the use of electrospun nanofibers to purify polluted water, wherein the distinctive characteristics of this type of nanofiber are essential when using them to remove organic and inorganic pollutants from wastewater, as well as for oil/water (O/W) separation.

Recent Progress and Potential Biomedical Applications of Electrospun Nanofibers in Regeneration of Tissues and Organs

Electrospun techniques are promising and flexible technologies to fabricate ultrafine fiber/nanofiber materials from diverse materials with unique characteristics under optimum conditions. These fabricated fibers/nanofibers via electrospinning can be easily assembled into several shapes of three-dimensional (3D) structures and can be combined with other nanomaterials. Therefore, electrospun nanofibers, with their structural and functional advantages, have gained considerable attention from scientific communities as suitable candidates in biomedical fields, such as the regeneration of tissues and organs, where they can mimic the network structure of collagen fiber in its natural extracellular matrix(es). Due to these special features, electrospinning has been revolutionized as a successful technique to fabricate such nanomaterials from polymer media. Therefore, this review reports on recent progress in electrospun nanofibers and their applications in various biomedical fields, such as bone cell proliferation, nerve regeneration, and vascular tissue, and skin tissue, engineering. The functionalization of the fabricated electrospun nanofibers with different materials furnishes them with promising properties to enhance their employment in various fields of biomedical applications. Finally, we highlight the challenges and outlooks to improve and enhance the application of electrospun nanofibers in these applications.

Heterocycles from cyclopropenones

Great attention has been paid to cyclopropenones as they are present in many natural sources.

A review on the synthesis of heteroannulated quinolones and their biological activities

The quinoline scaffold has become an important construction motif for the development of new drugs. The quinolones and their heteroannulated derivatives have high importance due to their diverse spectrum of biological activities as antifungal, anti-inflammatory, anti-diabetes, anti-Alzheimer's disease, antioxidant and diuretic activities. This review summarizes the various new, efficient and convenient synthetic approaches to synthesize diverse quinolone-based scaffolds and their biological activities. We also dealt with the important mechanism, the route and type of reactions of the obtained products. The biological activities of some heteroannulated quinolones were also discussed.

Substituted Pyrazoles and Their Heteroannulated Analogs-Recent Syntheses and Biological Activities

Pyrazoles are considered privileged scaffolds in medicinal chemistry. Previous reviews have discussed the importance of pyrazoles and their biological activities; however, few have dealt with the chemistry and the biology of heteroannulated derivatives. Therefore, we focused our attention on recent topics, up until 2020, for the synthesis of pyrazoles, their heteroannulated derivatives, and their applications as biologically active moieties. Moreover, we focused on traditional procedures used in the synthesis of pyrazoles.

An efficient click synthesis of chalcones derivatized with two 1-(2-quinolon-4-yl)-1,2,3-triazoles

Chalcones derivatized with 1-(2-quinolonyl)-1,2,3-triazoles were synthesized by reaction of 4-azido-2-quinolones with 1-phenyl-3-(4-propargyloxyphenyl)prop-2-en-1-one, or by aldol reaction of 4-{[1-(2-oxo-1,2-dihydroquinolin-4-yl)-1H-1,2,3-triazol-4-yl]methoxy}benzaldehydes with acetophenone. Whereas, chalcones bearing two 1-(2-quinolonyl)-1,2,3-triazoles were synthesized by reaction of 1,3-bis(4-propargyloxyphenyl)prop-2-en-1-one with 4-azido-2-quinolones, or by aldol condensation between 4-{4-[(4-acetylphenoxy)methyl]-1H-1,2,3-triazol-1-yl}quinolin-2(1H)-ones and 4-{[1-(2-oxo-1,2-dihydroquinolin-4-yl)-1H-1,2,3-triazol-4-yl]methoxy}benzaldehydes.

Design and synthesis of hydrazinecarbothioamide sulfones as potential antihyperglycemic agents

New hydrazinecarbothioamides with a phenylsulfonyl group were synthesized and their structures were identified by different spectroscopic data (¹ H NMR, ¹³ C NMR, two-dimensional NMR, mass spectrometry, elemental analysis, and single-crystal X-ray analysis). The mechanism describing the formation of the products was also discussed. The antidiabetic activity of the isolated products was investigated histochemically. The synthesized sulfonylalkylthiosemicarbazide exhibited antihyperglycemic activity in streptozotocin-induced diabetic mice. Compounds 5a and 5c significantly lowered the blood glucose level to 103.3 ± 1.8 and 102 ± 3.9 mg/dl, respectively. Also, they caused a significant decrease in malondialdehyde levels and normalized the glutathione levels in streptozotocin-induced diabetic mice, compared with the diabetic group. The results suggest that the synthesized hydrazinocarbothioamides may effectively inhibit the development of oxidative stress in diabetes.

Chemistry of Substituted Thiazinanes and Their Derivatives

Thiazinanes and its isomeric forms represent one of the most important heterocyclic compounds, and their derivatives represented a highly potent drug in disease treatment such as, 1,1-dioxido-1,2-thiazinan-1,6-naphthyridine, which has been shown to have anti-HIV activity by a mechanism that should work as anti-AIDS treatment, while (Z)-methyl 3-(naphthalen-1-ylimino)- 2-thia-4-azaspiro[5 5]undecane-4-carbodithioate showed analgesic activity, cephradine was used as antibiotic and chlormezanone was utilized as anticoagulants. All publications were interested in the chemistry of thiazine (partially or fully unsaturated heterocyclic six-membered ring containing nitrogen and sulfur), but no one was dealing with thiazinane itself which encouraged us to shed new light on these interesting heterocycles. This review was focused on the synthetic approaches of thiazinane derivatives and their chemical reactivity.

Design, Synthesis, and Molecular Docking of Paracyclophanyl-Thiazole Hybrids as Novel CDK1 Inhibitors and Apoptosis Inducing Anti-Melanoma Agents

Three new series of paracyclophanyl-dihydronaphtho[2,3-d]thiazoles and paracyclophanyl-thiazolium bromides were designed, synthesized, and characterized by their spectroscopic data, along with X-ray analysis. One-dose assay results of anticancer activity indicated that 3a–e had the highest ability to inhibit the proliferation of different cancer cell lines. Moreover, the hybrids 3c–e were selected for five-dose analyses to demonstrate a broad spectrum of antitumor activity without apparent selectivity. Interestingly, series I compounds (Z)-N-substituted-4,9-dihydronaphtho[2,3-d]thiazol-3(2H)-yl)-4′-[2.2]paracyclophanylamide) that are carrying 1,4-dihydronaphthoquinone were more active as antiproliferative agents than their naphthalene-containing congeners (series II: substituted 2-(4′-[2.2]paracyclophanyl)hydrazinyl)-4-(naphth-2-yl)-thiazol-3-ium bromide hybrids) and (series III: 3-(4′-[2.2]paracyclophanyl)amido-2-(cyclopropylamino)-4-(naphth-2-yl)thiazol-3-ium bromide) toward the SK-MEL-5 melanoma cell line. Further antiproliferation investigations of 3c and 3e on the healthy, normal unaffected SK-MEL-5 cell line indicated their relative safety. Compound 3c showed an inhibition of eight isoforms of cyclin-dependent kinases (CDK); however, it exhibited the lowest IC₅₀ of 54.8 nM on CDK1 in comparison to Dinaciclib as a reference. Additionally, compound 3c revealed a remarkable downregulation of phospho-Tyr15 with a level (7.45 pg/mL) close to the reference. 3c mainly showed cell cycle arrest in the pre-G1 and G2/M phases upon analysis of the SK-MEL-5 cell line. The sequential caspase-3 assay for 3c indicated a remarkable overexpression level. Finally, a molecular docking study was adopted to elucidate the binding mode and interactions of the target compounds with CDK1.

Synthesis of quinone-based heterocycles of broad-spectrum anticancer activity

A synthesis of benzo[ e][1,2,4]triazines and 1,2,4-triazolospiro[4,5]deca-2,6,9-trien-8-ones has been developed from reactions of amidrazones with 2-chloro-1,4-benzoquinone in EtOAc containing 0.5 mL of piperidine. This highly regioselective and one-pot process provided rapid access to 1,2,4-triazolospiro[4,5]deca-2,6,9-trien-8-ones (60%–70%) and benzo[ e][1,2,4]triazines (11%–18%). On reacting amidrazones with 5-hydroxy-1,4-naphthoquinone in an EtOAc/piperidine mixture, the reaction proceeded to give 5-hydroxy-2-(piperidin-1-yl)naphthalene-1,4-dione. The structures of the isolated products were proved by infrared, NMR (2D-NMR), mass spectra, and elemental analyses in addition to X-ray structure analysis. The reaction mechanisms are discussed. The anticancer screening of selected compounds showed broad-spectrum anticancer activity against most melanoma cancer cell lines, ovarian cancer OVCAR-3, central nervous system cancer SF-295 and U251, non-small cell lung cancer NCI-H23, renal cancer SN12C, and colon cancer HCT-15 and HCT-116. The selected compounds exhibited moderate to weak anticancer activity to other cell lines.

Synthesis of potentially new schiff bases of N-substituted-2-quinolonylacetohydrazides as anti-COVID-19 agents

We report herein a new series of synthesized N-substituted-2-quinolonylacetohydrazides aiming to evaluate their activity towards SARS-CoV-2. The structures of the obtained products were fully confirmed by NMR, mass, IR spectra and elemental analysis as well. Molecular docking calculations showed that most of the tested compounds possessed good binding affinity to the SARS-CoV-2 main protease (M^pro) comparable toRemdesivir.

Design, Synthesis, Molecular Docking, Antiapoptotic and Caspase-3 Inhibition of New 1,2,3-Triazole/Bis-2(1H)-Quinolinone Hybrids

A series of novel 1,2,3-triazoles hybridized with two quinolin-2-ones, was designed and synthesized through click reactions. The structures of the synthesized compounds were elucidated by NMR, IR, and mass spectra in addition to elemental analysis. The synthesized compounds were assessed for their antiapoptotic activity in testis, as testicular torsion is the main cause of male infertility. This effect was studied in light of decreasing tissue damage induced by I/R in the testis of rats using N-acetylcysteine (NAC) as an antiapoptotic reference. Compounds 6a-c were the most active antiapoptotic hybrids with significant measurements for malondialdehyde (MDA) and total antioxidant capacity (TAC) and the apoptotic biomarkers (testicular testosterone, TNFα, and caspase-3) in comparison to the reference. A preliminary mechanistic study was performed to improve the antiapoptotic activity through caspase-3 inhibition. A compound assigned as 6-methoxy-4-(4-(((2-oxo-1,2-dihydroquinolin-4-yl)oxy)methyl)-1H-1,2,3-triazol-1-yl)quinolin-2(1H)-one (6c) was selected as a representative of the most active hybrids in comparison to NAC. Assay of cytochrome C for 6c revealed an attenuation of cytochrome C level about 3.54 fold, comparable to NAC (4.13 fold). In caspases-3,8,9 assays, 6c was found to exhibit more potency and selectivity toward caspase-3 than other caspases. The testicular histopathological investigation was carried out on all targeted compounds 6a-g, indicating a significant improvement in the spermatogenesis process for compounds 6a-c if compared to the reference relative to the control. Finally, molecular docking studies were done at the caspase-3 active site to suggest possible binding modes. Hence, it could conceivably be hypothesized that compounds 6a-c could be considered good lead candidate compounds as antiapoptotic agents.

Regioselective synthesis of new 7,8-dichlorobenzofuro[3,2-c]quinoline-6,9,10(5H)-triones from reactions of 4-hydroxy-2-quinolones with 3,4,5,6-tetrachloro-1,2-benzoquinone

A novel series of 7,8-dichlorobenzofuro[3,2- c]quinoline-6,9,10(5 H)-triones was obtained regioselectively in good yields. The products were formed by the reactions of the 4-hydroxy-2(1 H)-quinolinones with 3,4,5,6-tetrachloro-1,2-benzoquinone in tetrahydrofuran as the solvent. Infrared, nuclear magnetic resonance (two-dimensional nuclear magnetic resonance), mass spectra and elemental analysis were used to elucidate the structures of new compounds.

Regioselective and stereoselective synthesis of epithiomethanoiminoindeno[1,2-b]furan-3-carbonitrile: heterocyclic [3.3.3]propellanes

Synthesis of heteropropellanes in one step: the reaction between dicyanomethylene-1,3-indanedione (CNIND) and N-substituted-2-(2,4-dinitrophenyl)hydrazinecarbothioamides, furnished (3aR,8bS,Z)-2-amino-9-substituted-10-(2-(2,4-dinitrophenyl)hydrazono)-4-oxo-4H-3a,8b-(epithiomethanoimino)indeno[1,2-b]furan-3-carbonitrile as a type of (2,4-dinitrophenyl)hydrazono[3.3.3]propellanes in good yields as single diastereomers. Structure determination and confirmation of the synthesized products have been achieved using various and modern spectroscopic techniques such as IR, NMR (¹H NMR and ¹³C NMR), mass spectrometry, as well as X-ray crystal analysis. The X-ray structure data cleared that the molecule of 7a was crystalized as monoclinic, space group C2/c (no.15).

Identification and molecular modeling of new quinolin-2-one thiosemicarbazide scaffold with antimicrobial urease inhibitory activity

A new series of 6-substituted quinolin-2-one thiosemicarbazides 6a-j has been synthesized. The structure of the target compounds was proved by different spectroscopic and elemental analyses. All the designed final compounds were evaluated for their in vitro activity against the urease-producing R. mucilaginosa and Proteus mirabilis bacteria as fungal and bacterial pathogens, respectively. Moreover, all compounds were in vitro tested as potential urease inhibitors using the cup-plate diffusion method. Compounds 6a and 6b were the most active with (IC₅₀ = 0.58 ± 0.15 and 0.43 ± 0.09 µM), respectively, in comparison with lead compound I (IC₅₀ = 1.13 ± 0.00 µM). Also, the designed compounds were docked into urease proteins (ID: 3LA4 and ID: 4UBP) using Open Eye^® software to understand correctly about ligand-receptor interactions. The docking results revealed that the designed compounds can interact with the active site of the enzyme through multiple strong hydrogen bonds. Moreover, rapid overlay of chemical structures' analysis was described to understand the 3D QSAR of synthesized compounds as urease inhibitors. The results emphasize the importance of polar thiosemicarbazide directly linked to 6-substituted quinolone moieties as promising antimicrobial urease inhibitors.

5-Carbohydrazide and 5-carbonylazide of pyrazolo[3,4-b]pyridines as reactive intermediates in the synthesis of various heterocyclic derivatives

5-Carbohydrazides and 5-carbonylazides of pyrazolo[3,4- b]pyridines are used to synthesize new heterocyclic derivatives. Some unexpected behaviors are observed in the reactions of the above two species. The structures of the obtained compounds are proved by spectroscopic studies together with elemental and X-ray structure analyses.

Design, synthesis, and DNA interaction studies of furo-imidazo[3.3.3]propellane derivatives: Potential anticancer agents

A large number of natural products containing the propellane scaffold have been reported to exhibit cytotoxicity against several cancers; however, their mechanism of action is still unknown. Anticancer drugs targeting DNA are mainly composed of small planar molecule/s that can interact with the DNA helix, causing DNA malfunction and cell death. The aim of this study was to design and synthesize propellane derivatives that can act as DNA intercalators and/or groove binders. The unique structure of the propellane derivatives and their ability to display planar ligands with numerous possible geometries, renders them potential starting points to design new drugs targeting DNA in cancer cells. New substituted furo-imidazo[3.3.3]propellanes were synthesized via the reaction of substituted alkenylidene-hydrazinecarbothioamides with 2-(1,3-dioxo-2,3-dihydro-1H-2-ylidene)propanedinitrile in tetrahydrofuran at room temperature. The structures of the products were confirmed by a combination of elemental analysis, NMR, ESI-MS, IR and single crystal X-ray analysis. Interestingly, 5c, 5d and 5f showed an ability to interact with Calf Thymus DNA (CT-DNA). Their DNA-binding mode was investigated using a combination of absorption spectroscopy, DNA melting, viscosity, CD spectroscopy measurements, as well as competitive binding studies with several dyes. Their cytotoxicity was evaluated against the NCI-60 panel of cancer cell lines. 5c, 5d and 5f exhibited similar anti-proliferative activity against the A549 non-small cell lung cancer (NSCLC) cell line. Further mechanistic studies revealed their ability to induce DNA damage in the A549 cell line, as well as apoptosis, evidenced by elevated Annexin V expression, enhanced caspase 3/7 activation and PARP cleavage. In this study, we present the potential for designing novel propellanes to provoke cytotoxic activity, likely through DNA binding-induced DNA damage and apoptosis.