Hybrid Molecules Composed of 2,4-Diamino-1,3,5-triazines and 2-Imino-Coumarins and Coumarins. Synthesis and Cytotoxic Properties

Metabolic profiling, antimicrobial, anticancer, and in vitro and in silico immunomodulatory investigation of Aspergillus niger OR730979 isolated from the Western Desert, Egypt

Ten fungal species were isolated from soil in the Western Desert and Wadi El-Natron in Egypt. All fungal isolates were morphologically recognized down to the species level. Methanol extracts of fungal mycelia and ethyl acetate extracts of culture filtrate from the isolated fungi were evaluated for antimicrobial activity against six pathogenic bacteria and one pathogenic yeast (Candida albicans ATCC20231). Only ethyl acetate extracts of Fusarium circinatum, Aspergillus niger, and Aspergillus terreus culture filtrates showed significant antimicrobial activity against the majority of the investigated pathogens. The culture filtrate extract of Aspergillus niger exhibited notable cytotoxicity towards the breast cancer (MCF-7) cell line, with the lowest detected IC50 recorded at 8 μg/μl. Whereas Fusarium circinatum and Aspergillus terreus had IC50s of 15.91 μg/μl and 18 μg/μl, respectively. A gas chromatography-mass spectroscopy (GC-MS) investigation of A. niger's potent extract revealed 23 compounds with different biological activities. Glycidyleoleate was found to be the main extract component. Aspergillus niger extract was chosen to study its possible cytotoxic mechanism. The extract was found to induce apoptosis and cell cycle arrest at the < 2n stage. Despite a significant increase in caspases 8 and 9, the production levels of tumor necrosis factor α (TNF-α) and interleukin 6 (IL-6) have shown a significant decrease. The high interaction of glycidyleoleate against the studied cytokines' binding receptors was demonstrated via docking studies. In conclusion, the available data revealed that the culture filtrate extract of A. niger possesses promising antimicrobial, cytotoxic, and immunomodulatory properties.

Selective aerobic coupling of amines to imines using solar spectrum-responsive flower-like Nen-graphene quantum dots (GQDs) decorated with 2, 4-dinitrophenylhydrazine (PH) as a photocatalyst

Indeed, the development of ecologically benign molecular fabrication methods for highly efficient graphene quantum dots-based photocatalysts is of great significant. Graphene quantum dots-based photocatalysts have promising applications in various field, including environmental remediation, energy conversion, and splitting of water. However, ensuring resource reusability and minimizing the environmental impact are crucial considerations in the development. From this perspective, attention has also been paid to the creation of easy to make solar light harvesting graphene quantum dots-based photocatalysts for synthesising pharmaceuticals and functional imines compounds. Imines are excellent significant building blocks in pharmaceutical chemistry and excellent examples of these valuable compounds' synthetic intermediates, and the environmentally friendly oxidative synthesis of imines from amines. Therefore, herein, we designed a facile and efficient condensation route to synthesize the Nen-GQDs@PH photocatalyst. This route involves coupling of 2,4-dinitrophenylhydrazine (PH) with nitrogen-enriched graphene quantum dots (Nen-GQDs). The Nen-GQDs@PH as photocatalyst functions in a highly selective and efficient manner, leading to high amines conversion efficiency to imines (95%). Our results highlight a novel and environmentally safe approach for generating highly selective imines from various types of amines, setting a new benchmark in the current research field.

Advances of antitumor drug discovery in traditional Chinese medicine and natural active products by using multi-active components combination

The antitumor efficacy of Chinese herbal medicines has been widely recognized. Leading compounds such as sterols, glycosides, flavonoids, alkaloids, terpenoids, phenylpropanoids, and polyketides constitute their complex active components. The antitumor monomers derived from Chinese medicine possess an attractive anticancer activity. However, their use was limited by low bioavailability, significant toxicity, and side effects, hindering their clinical applications. Recently, new chemical entities have been designed and synthesized by combining natural drugs with other small drug molecules or active moieties to improve the antitumor activity and selectivity, and reduce side effects. Such a novel conjugated drug that can interact with several vital biological targets in cells may have a more significant or synergistic anticancer activity than a single-molecule drug. In addition, antitumor conjugates could be obtained by combining pharmacophores containing two or more known drugs or leading compounds. Based on these studies, the new drug research and development could be greatly shortened. This study reviews the research progress of conjugates with antitumor activity based on Chinese herbal medicine. It is expected to serve as a valuable reference to antitumor drug research and clinical application of traditional Chinese medicine.

Recent updates on 1,2,3-, 1,2,4-, and 1,3,5-triazine hybrids (2017-present): The anticancer activity, structure-activity relationships, and mechanisms of action

Cancer is one of the leading causes of death across the world, and the prevalence and mortality rates of cancer will continue to grow. Chemotherapeutics play a critical role in cancer therapy, but drug resistance and side effects are major hurdles to effective treatment, evoking an immediate need for the discovery of new anticancer agents. Triazines including 1,2,3-, 1,2,4-, and 1,3,5-triazine have occupied a propitious place in drug design and development due to their excellent pharmacological profiles. Mechanistically, triazine derivatives could interfere with various signaling pathways to induce cancer cell death. Hence, triazine derivatives possess potential in vitro and in vivo efficacy against diverse cancers. In particular, triazine hybrids are able to overcome drug resistance and reduce side effects. Moreover, several triazine hybrids such as brivanib (indole-containing pyrrolo[2,1-f][1,2,4]triazine), gedatolisib (1,3,5-triazine-urea hybrid), and enasidenib (1,3,5-triazine-pyridine hybrid) have already been available in the market. Accordingly, triazine hybrids are useful scaffolds for the discovery of novel anticancer chemotherapeutics. This review focuses on the anticancer activity of 1,2,3-, 1,2,4-, and 1,3,5-triazine hybrids, together with the structure-activity relationships and mechanisms of action developed from 2017 to the present. The enriched structure-activity relationships may be useful for further rational drug development of triazine hybrids as potential clinical candidates.

A Review on Recent Approaches on Molecular Docking Studies of Novel Compounds Targeting Acetylcholinesterase in Alzheimer Disease

Alzheimer's disease (AD), a neurodegenerative brain disorder that affects millions of people worldwide, is characterized by memory loss and cognitive decline. Low levels of acetylcholine and abnormal levels of beta-amyloid, T protein aggregation, inflammation, and oxidative stress, have been associated with AD, and therefore, research has been oriented towards the cholinergic system and primarily on acetylcholinesterase (AChE) inhibitors. In this review, we are focusing on the discovery of AChE inhibitors using computer-based modeling and simulation techniques, covering the recent literature from 2018-2022. More specifically, the review discusses the structures of novel, potent acetylcholinesterase inhibitors and their binding mode to AChE, as well as the physicochemical requirements for the design of potential AChE inhibitors.

Synthesis, Structure and Cytotoxic Properties of Copper(II) Complexes of 2-Iminocoumarins Bearing a 1,3,5-Triazine or Benzoxazole/Benzothiazole Moiety

A series of copper(II) complexes of 2-imino-2H-chromen-3-yl-1,3,5-triazines 2a-h, 3-(benzoxazol-2-yl)-2H-chromen-2-imines 4a-b, and 3-(benzothiazol-2-yl)-2H-chromen-2-imines 6a-c were obtained by reacting of appropriate 2-iminocoumarin ligands L1a-h, L3a-b, and L5a-c with 3-fold molar excess of copper(II) chloride. The structure of these compounds was confirmed by IR spectroscopy, elemental analysis, and single-crystal X-ray diffraction data (2f, 2g, 2h, and 6c). All the synthesized complexes were screened for their activity against five human cancer cell lines: DAN-G, A-427, LCLC-103H, SISO, and RT-4 by using a crystal violet microtiter plate assay and relationships between structure and in vitro cytotoxic activity are discussed. The coordination of 2-iminocoumarins with copper(II) ions resulted in complexes 2a-h, 4a-b, and 6a-c with significant inhibitory properties toward tested tumor cell lines with IC₅₀ values ranging from 0.04 μM to 15.66 μM. In comparison to the free ligands L1a-h, L3a-b, and L5a-c, the newly prepared Cu(II) complexes often displayed increased activity. In the series of copper(II) complexes of 2-imino-2H-chromen-3-yl-1,3,5-triazines 2a-h the most potent compound 2g contained a 4-phenylpiperazine moiety at position 6 of the 1,3,5-triazine ring and an electron-donating diethylamino group at position 7' of the 2-iminocoumarin scaffold. Among the Cu(II) complexes of 3-(benzoxazol-2-yl)-2H-chromen-2-imines 4a-b and 3-(benzothiazol-2-yl)-2H-chromen-2-imines 6a-c the most active was benzoxazole-2-iminocoumarin 4b that also possessed a diethylamino group at position 7' of the 2-iminocoumarin moiety. Moreover, compound 4b was found to be the most prominent agent and displayed the higher potency than cisplatin against tested cell lines.

Recent Advances in the Biological Activity of s-Triazine Core Compounds

An effective strategy for successful chemotherapy relies on creating compounds with high selectivity against cancer cells compared to normal cells and relatively low cytotoxicity. One such approach is the discovery of critical points in cancer cells, i.e., where specific enzymes that are potential therapeutic targets are generated. Triazine is a six-membered heterocyclic ring compound with three nitrogen replacing carbon-hydrogen units in the benzene ring structure. The subject of this review is the symmetrical 1,3,5-triazine, known as s-triazine. 1,3,5-triazine is one of the oldest heterocyclic compounds available. Because of its low cost and high availability, it has attracted researcher attention for novel synthesis. s-Triazine has a weak base, it has much weaker resonance energy than benzene, therefore, nucleophilic substitution is preferred to electrophilic substitution. Heterocyclic bearing a symmetrical s-triazine core represents an interesting class of compounds possessing a wide spectrum of biological properties such as anti-cancer, antiviral, fungicidal, insecticidal, bactericidal, herbicidal and antimicrobial, antimalarial agents. They also have applications as dyes, lubricants, and analytical reagents. Hence, the group of 1,3,5-triazine derivatives has developed over the years. Triazine is not only the core amongst them, but is also a factor increasing the kinetic potential of the entire derivatives. Modifying the structure and introducing new substituents makes it possible to obtain compounds with broad inhibitory activity on processes such as proliferation. In some cases, s-triazine derivatives induce cell apoptosis. In this review we will present currently investigated 1,3,5-triazine derivatives with anti-cancer activities, with particular emphasis on their inhibition of enzymes involved in the process of tumorigenesis.

Mild Biamidine-Transfer Conditions for the Synthesis of Aliphatic Biguanides

This study focuses on the development of new synthetic pathways to monosubstituted biguanides from amines. An exhaustive comparison of the conditions and reagents used for biamidine transfer was performed. New reagents were synthesized and optimized conditions for the synthesis of substituted biguanides under mild conditions were developed. Eventually, two high-yielding and straightforward protocols for the transfer of a biamidine group to various amines are proposed and their scope and limitations have been explored. These conditions include: i) a direct chromatography-free procedure and ii) an eco-friendly procedure in water compatible with bioinspired molecules. They are particularly efficient for the demanding conversion of aliphatic amines.

1,3,5-Triazine: A versatile pharmacophore with diverse biological activities

1,3,5-Triazine and its derivatives have been the epicenter of chemotherapeutic molecules due to their effective biological activities, such as antibacterial, fungicidal, antimalarial, anticancer, antiviral, antimicrobial, anti-inflammatory, antiamoebic, and antitubercular activities. The present review represents a summarized report of the crucial biological activities possessed by substituted 1,3,5-triazine derivatives, with special attention to the most potent compounds.

Biguanide-Based Synthesis of 1,3,5-Triazine Derivatives with Anticancer Activity and 1,3,5-Triazine Incorporated Calcium Citrate Nanoparticles

Twelve derivatives of biguanide-derived 1,3,5-triazines, a promising class of anticancer agent, were synthesised and evaluated for their anticancer activity against two colorectal cancer cell lines-HCT116 and SW620. 2c and 3c which are the derivatives containing o-hydroxyphenyl substituents exhibited the highest activity with IC50 against both cell lines in the range of 20-27 µM, which is comparable to the IC50 of cisplatin reference. Moreover, the potential use of the calcium citrate nanoparticles (CaCit NPs) as a platform for drug delivery system was studied on a selected 1,3,5-triazine derivative 2a. Condition optimisation revealed that the source of citrate ions and reaction time significantly influence the morphology, size and %drug loading of the particles. With the optimised conditions, "CaCit-2a NPs" were successfully synthesised with the size of 148 ± 23 nm and %drug loading of up to 16.3%. Furthermore, it was found that the release of 2a from the synthesised CaCit-2a NPs is pH-responsive, and 2a could be control released under the acidic cancer environment. The knowledge from this study is perceptive for further development of the 1,3,5-triazine-based anticancer drugs and provide the platform for the incorporation of other drugs in the CaCit NPs in the future.

Synthesis, Structure and Cytotoxicity Testing of Novel 7-(4,5-dihydro-1H-imidazol-2-yl)-2-aryl-6,7-dihydro-2H-imidazo[2,1-c][1,2,4]triazol-3(5H)-Imine Derivatives

The appropriate 1-arylhydrazinecarbonitriles 1a-c are subjected to the reaction with 2-chloro-4,5-dihydro-1H-imidazole (2), yielding 7-(4,5-dihydro-1H-imidazol-2-yl)-2-aryl-6,7-dihydro-2H-imidazo[2,1-c][1,2,4]triazol-3(5H)-imines 3a-c, which are subsequently converted into the corresponding amides 4a-e, 8a-c, sulfonamides 5a-n, 9, ureas 6a-I, and thioureas 7a-d. The structures of the newly prepared derivatives 3a-c, 4a-e, 5a-n, 6a-i, 7a-d, 8a-c, and 9 are confirmed by IR, NMR spectroscopic data, as well as single-crystal X-ray analyses of 5e and 8c. The in vitro cytotoxic potency of these compounds is determined on a panel of human cancer cell lines, and the relationships between structure and antitumor activity are discussed. The most active 4-chloro-N-(2-(4-chlorophenyl)-7-(4,5-dihydro-1H-imidazol-2-yl)-6,7-dihydro-2H-imidazo[2,1-c][1,2,4]triazol-3(5H)-ylidene)benzamide (4e) and N-(7-(4,5-dihydro-1H-imidazol-2-yl)-2-(p-tolyl)-6,7-dihydro-2H-imidazo[2,1-c][1,2,4]triazol-3(5H)-ylidene)-[1,1'-biphenyl]-4-sulfonamide (5l) inhibits the growth of the cervical cancer SISO and bladder cancer RT-112 cell lines with IC50 values in the range of 2.38-3.77 μM. Moreover, N-(7-(4,5-dihydro-1H-imidazol-2-yl)-2-phenyl-6,7-dihydro-2H-imidazo[2,1-c][1,2,4]triazol-3(5H)-ylidene)-4-phenoxybenzenesulfonamide (5m) has the best selectivity towards the SISO cell line and induces apoptosis in this cell line.

Synthesis, characterization, inhibition effects, and molecular docking studies as acetylcholinesterase, α-glycosidase, and carbonic anhydrase inhibitors of novel benzenesulfonamides incorporating 1,3,5-triazine structural motifs

Some metabolic enzyme inhibitors can be used in the treatment of many diseases. Therefore, synthesis and determination of alternative inhibitors are essential. In this study, the inhibition effect of newly synthesized compounds on carbonic anhydrase (cytosolic isoforms, hCA I and hCA II), α-glycosidase (α-GLY), and acetylcholinesterase (AChE) were investigated. The possible binding mechanism of the compounds with a high inhibitory effect on the active site of the enzyme was demonstrated by molecular docking method. We investigated the inhibition effects of novel synthesized compounds (MZ1-MZ11) on metabolic enzymes such as α-GLY, AChE, and hCA I and II. The compound MZ6 for AChE, MZ8 for CA I and CA II and MZ7 for α-GLY showed a very active inhibition profile (KIs 51.67 ± 4.76 for hCA I, 40.35 ± 5.74 nM for hCA II, 41.74 ± 8.08 nM for α-GLY and 335.76 ± 46.91 nM for AChE). The novel synthesized compounds (MZ1-MZ11) have a higher enzyme (α-GLY, AChE, hCA I, and II) inhibitory potential than ACR, TAC, and AZA, respectively. The compounds may have the potential to be used as alternative medicines after further research in the treatment of many diseases such as diabetes, Alzheimer's disease, heart failure, ulcer, and epilepsy.

Synthesis of novel star-shaped molecules based on a 1,3,5-triazine core linked to different heterocyclic systems as novel hybrid molecules

The synthesis of novel star-shaped compounds based on an s-triazine core and linked to hexahydroacridinediones, pyrimido[4,5-b]quinolones, 1H-isoquinolino[2,1-a]quinolines, tetrahydro-4H-chromenes, dihydropyrano[2,3-c]pyrazoles, thiazole, or benzothiazole as new hybrid molecules through Michael and Hantzsch reactions is reported. For this purpose, 2,4,6-tris(4-formylphenoxy)benzaldehyde was used as a versatile precursor.

The synthesis of novel star-shaped compounds based on an s-triazine core and linked to different heterocycles as new hybrid molecules through Michael and Hantzsch reactions is reported.

Antiangiogenic Effects of Coumarins against Cancer: From Chemistry to Medicine

Angiogenesis, the process of formation and recruitment of new blood vessels from pre-existing vessels, plays an important role in the development of cancer. Therefore, the use of antiangiogenic agents is one of the most critical strategies for the treatment of cancer. In addition, the complexity of cancer pathogenicity raises the need for multi-targeting agents. Coumarins are multi-targeting natural agents belonging to the class of benzopyrones. Coumarins have several biological and pharmacological effects, including antimicrobial, antioxidant, anti-inflammation, anticoagulant, anxiolytic, analgesic, and anticancer properties. Several reports have shown that the anticancer effect of coumarins and their derivatives are mediated through targeting angiogenesis by modulating the functions of vascular endothelial growth factor as well as vascular endothelial growth factor receptor 2, which are involved in cancer pathogenesis. In the present review, we focus on the antiangiogenic effects of coumarins and related structure-activity relationships with particular emphasis on cancer.