New chemical tools for investigating human mitotic kinesin Eg5

Dihydropyrimidine derivatives as MDM2 inhibitors

One of the chief pathways to regulate p53 levels is MDM2 protein, which negatively controls p53 by direct inhibition. Many cancers overproduce MDM2 protein to interrupt p53 functions. Therefore, impeding MDM2's binding to p53 can reactivate p53 in tumor cells may suggest an effective approach for tumor therapy. Here, some Monastrol derivatives were designed in silico as MDM2 inhibitors, and their initial cytotoxicity was evaluated in vitro on MFC-7 and MDA-MB-231 cells. A small library of Monastrol derivatives was created, and virtual screening (VS) was performed on them. The first-ranked compound, which was extracted from VS, and the other six compounds 5a-5f were selected to carry out the single-docking and docking with explicit waters. The compound with the best average results was then subjected to molecular dynamic (MD) simulation. Compounds 5a-5f were chemically synthesized and evaluated in vitro for their initial cytotoxicity on MFC-7 and MDA-MB-231 cells by MTT assay. The best compound was compound 5d with ΔGave  = -10.35 kcal/mol. MD simulation revealed a median potency in comparison with Nutlin-3a. The MTT assay confirmed the docking and MD experiments. 5d has an IC50 of 60.09 μM on MCF-7 cells. We attempted to use Monastrol scaffold as a potent inhibitor of MDM2 rather than an Eg5 inhibitor using in silico modification. The results obtained from the in silico and in vitro evaluations were noteworthy and warranted much more effort in the future.

The Isoflavanoid (+)-PTC Regulates Cell-Cycle Progression and Mitotic Spindle Assembly in a Prostate Cancer Cell Line

Prostate cancer is the second most common malignancy in men and the development of effective therapeutic strategies remains challenging when more advanced, androgen-independent or insensitive forms are involved. Accordingly, we have evaluated, using flow cytometry, confocal microscopy and image analysis, the anti-proliferative effects of (+)-2,3,9-trimethoxypterocarpan [(+)-PTC, 1] on relevant human prostate cancer cells as well as its capacity to control mitosis within them. In particular, the studies reported herein reveal that (+)-PTC exerts anti-proliferative activity against the PC-3 cell lines by regulating cell-cycle progression with mitosis being arrested in the prophase or prometaphase. Furthermore, it emerges that treatment of the target cells with this compound results in the formation of monopolar spindles, disorganized centrosomes and extensively disrupted γ-tubulin distributions while centriole replication remains unaffected. Such effects suggest (+)-PTC should be considered as a possible therapy for androgen-insensitive/independent prostate cancer.

Quinoline-dihydropyrimidin-2(1H)-one hybrids: Synthesis, biological activity and mechanistic studies

A novel class of quinoline-dihydropyrimidin-2(1H)-one (DHPM) hybrids was synthesized and in vitro antiplasmodial activity was evaluated against chloroquine sensitive (D10) and chloroquine resistant (Dd2) strains of Plasmodium falciparum, the human malaria parasite. The antiplasmodial activity was compared to previously reported DHPM based molecular hybrids. Dual mode of antiplasmodial action of the most active member has been evaluated through heme binding study and in silico docking in the active site of dihydrofolate enzymes (wild-type as well as mutant). Favourable pharmacokinetic parameters were predicted in the ADMET evaluation. The new hybrids were also tested against a number of DNA and RNA viruses. No antiviral activity was found, except for one hybrid  that showed mild inhibitory activity against two strains of cytomegalovirus (AD-169 and Davis), The most active hybrid  was found to be a selective inhibitor of the growth of P. falciparum as well as a modest inhibitor of varicella zoster virus in HEL cells. Cytotoxicity of all hybrids was assessed in HEL, HeLa, Vero, MDCK, and CRFK cell cultures.

Synthesis of Pyrimidine Hybrids Based on 4H-Pyran and 4H-Chromene Privileged Structures

Abstract:

A combinatorial library of pyrimidine hybrids based on 4H-chromene and 4H-pyran privileged structures have been developed by reaction of phenyl isothiocyanate with chromene derivatives 1a-j and pyranopyrazoles 2a-f in refluxing dry pyridine, respectively. Thus, the target pyrimidine hybrids 3a-j and 4a-f were obtained in good yields with a simple reaction strategy.

Green synthesis, structural analysis and anticancer activity of dihydropyrimidinone derivatives

In this study, for the first time, we have used Citrus macroptera juice to synthesize dihydropyrimidine (DHPM) derivatives via the Biginelli reaction, which showed better yield, shorter reaction time, and did not require an organic solvent for the reaction. A series of DHPM derivatives were synthesized, and characterized, and structural analysis was achieved through SCXRD & Hirshfeld surface analysis. We observed that these synthesized dihydropyrimidine (DHPM) derivatives showed C–H⋯π, C–H⋯O, C–H⋯N, C–H⋯C, lone pair⋯π, π⋯π, etc. interactions. We also performed in silico studies for their inhibitory activities against human kinesin Eg5 enzyme, and the cytotoxic activity of the synthesized compounds was carried out against A549 lung adenocarcinoma cells. In silico analysis demonstrated that compounds with a chloro-group at the 3- or 4-position in the substituted ring of DHPM showed higher binding affinity for the human kinesin Eg5 enzyme (−7.9 kcal mol⁻¹) than the standard drug monastrol (−7.8 kcal mol⁻¹). Furthermore, in vitro cellular studies revealed that compounds with a chloro-group at the 3- or 4-position in the substituted ring of DHPM induced significant cell death in human A549 lung adenocarcinoma cells. This result indicates that a deactivating group (chlorine) at the 3- or 4-position in the substituted ring of DHPM might be a promising anticancer drug candidate for treating different types of cancers, particularly cancer of the lung.

Green synthesis, study and development of new potent dihydropyrimidinone analogues as anti-cancer drugs.

Hybrids of 4-hydroxy derivatives of goniothalamin and piplartine bearing a diester or a 1,2,3-triazole linker as antiproliferative agents

A library of nine hybrids of 4-hydroxygoniothalamin (2), 4-hydroxypiplartine (4), monastrol (5) and oxo-monastrol (6) was prepared via a modular synthetic route with a diester or a 1,2,3-triazole as linkers. The compounds were assayed against a panel of human cancer cell lines, including MCF-7 (breast adenocarcinoma), HeLa (cervical adenocarcinoma), Caco-2 (colorectal adenocarcinoma) and PC3 (prostate adenocarcinoma), as well as against normal breast (MCF10A) and prostate (PNT2) cells. In general, hybrids with an ester linker containing 4-hydroxypiplartine (4) were more potent than the corresponding hybrids with 4-hydroxygoniothalamin (2). On the other hand, compounds presenting the 1,2,3-triazole linker displayed enhanced cytotoxicity and selectivity when compared to their corresponding hybrids with the diester linker. The 4-hydroxypiplartine-based hybrids 12 and 22 displayed high cytotoxicity (IC50 values below 10 μM) against all cancer cells studied, especially in MCF-7 cells with IC50 values of 1.7 ± 0.1 and 1.6 ± 0.9 μM, respectively. Furthermore, the 4-hydroxygoniothalamin-monastrol hybrid (compound 21) and the 4-hydroxypiplartine-oxo-monastrol hybrid (compound 25), both bearing a 1,2,3-triazole linker, displayed high selectivity and potency towards breast cancer cell line (MCF-7 vs. MCF10 cells, selectivity index = 15.8 and 7.1, respectively), while the 4-hydroxypiplartine -4-hydroxymethylgoniothalamin hybrid with a diester linker (compound 33) showed high selectivity towards melanoma cancer cells (selectivity index = 9.6). Antiproliferative and pro-apoptotic potential of compounds 12 and 22 against MCF-7 cancer cells were further investigated. Cell cycle studies revealed increased G2/M population in MCF-7 cultures as well as reduced G0/G1 population compared to the control groups indicating cell cycle arrest in G2/M phase. In addition, the frequency of positive cells for annexin V was higher in treated samples suggesting that compounds 12 and 22 induce apoptosis in estrogen-positive MCF-7 cells.

Synthesis, crystal structure and antibacterial studies of dihydropyrimidines and their regioselectively oxidized products

The syntheses and investigations of new biologically active derivatives of dihydropyrimidines by Biginelli reaction in the presence of copper triflate are reported. Due to the fact that salicylaldehyde and its derivatives under Biginelli reaction conditions can lead to the formation of 2 types of dihydropyrimidines, the influence of copper triflate on product formation was also investigated. In addition to this, regioselective oxidation of dihydropyrimidines was performed in the presence of cerium ammonium nitrate and novel oxidized dihydropyrimidines were obtained. Single crystals of some of them were obtained and as a result, the structures of them were investigated by X-ray diffraction method, which allows determining the presence of hydrogen bonds in their structures. In addition to this, the presence of hydrogen bonds in their structures affects the formation of the corresponding tautomer during oxidizing of dihydropyrimidines. Since dihydropyrimidines are claimed to be biologically active compounds, activities of the synthesized compounds were studied against Acinetobacter baumanii, Escherichia coli, Pseudomonas aeruginosa, Klebsiella pneumoniae and Staphylococcus aureus bacteria.

Known methods of synthesis of dihydropyrimidines and their oxidized products were modified, the impact of hydrogen bonds on stabilization of preferred tautomer and biological activities were studied.

A novel H2S releasing-monastrol hybrid (MADTOH) inhibits L-type calcium channels

A new alleged monastrol-H₂S releasing hybrid, named MADTOH, was designed based on the structure of monastrol (M) and 5-(4-hydroxyphenyl)-3H-1,2-dithiole-3-thione (ADTOH) and synthesized in 7.8% overall yield.

Dihydropyrimidinones Scaffold as a Promising Nucleus for Synthetic Profile and Various Therapeutic Targets: A Review

BACKGROUND

This review elaborates the updated synthetic and pharmacological approaches of a known group of dihydropyrimidinones/thiones from the multi-component reaction like Biginelli reaction, which was named Pietro Biginelli in 1891. This review consists of the reaction of an aromatic aldehyde, urea and ethyl acetoacetate leading to dihydropyrimidinone/thione. Currently, the scientific movement to develop economically viable green methods using compounds that are reusable, non-volatile, easily obtained, etc. Objective: This review covers the recent synthesis and pharmacological advancement of dihydropyrimidinones/ thiones moiety, along with covering the structure-activity relationship of the most potent compounds, which may prove to become better, more efficacious and safer agents. Thus, this review may help the researchers in drug designing and development of new Dihydropyrimidinones entities.

CONCLUSION

This review focuses on the wide application of dihydropyrimidinone/thione review reports the design, synthesis and pharmacological activities of nitrogen-sulphur containing dihydropyrimidinone moiety by using multi-component reaction. Dihydropyrimidinones (DHPM) pharmacophore is an important heterocyclic ring in medicinal chemistry. It is derived from multi-component reactions, "Biginelli reaction" and plays a critical role as anticancer, antioxidant, antimicrobial, anti-inflammatory, anti-HIV-1, antimalarial, anti-inflammatory, antihypertensive and anti-tubercular agents. Exhaustive research has led to its vast biological profile, with a wide range of therapeutic application.

Multicomponent Reactions in Polymer Chemistry Utilizing Heavier Main Group Elements

Herein, a concise overview of the use of heavier main group elements in multicomponent reactions and their use in polymer chemistry is provided. Incorporating heavier elements into macromolecular structures via multicomponent reactions allows for the rapid development of materials with unique properties that are not readily achieved using carbon, nitrogen, and/or oxygen. Elements in Group 13, Group 14, Group 15, and Group 16 are specifically covered examining both the familiar and unfamiliar properties of these elements and how they are used in multicomponent chemistry. Furthermore, elements that both take part in the reaction mechanism and remain in the macromolecular structure upon completion are only briefly explored. Some of the state-of-the-art work going into developing these heavier element multicomponent reactions are highlighted and it is hoped to inspire other polymer chemists to explore other parts of the periodic table.

Nanocrystalline ZnO: A Competent and Reusable Catalyst for the Preparation of Pharmacology Relevant Heterocycles in the Aqueous Medium

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Nanoparticle catalyzed synthesis is a green and convenient method to achieve most of the chemical transformations in water or other green solvents. Nanoparticle ensures an easy isolation process of catalyst as well as products from the reaction mixture avoiding the hectic work up procedure. Zinc oxide is a biocompatible, environmentally benign and economically viable nanocatalyst with effectivity comparable to the other metal nanocatalyst employed in several reaction strategies. This review mainly focuses on the recent applications of zinc oxide in the synthesis of biologically important heterocyclic molecules under sustainable reaction conditions.

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Application of zinc oxide in organic synthesis: Considering the achievable advantages of this nanocatalyst, presently several research groups are paying attention in anchoring zincoxide or its modified structure in several types of organic conversions e.g. multicomponent reactions, ligand-free coupling reactions, cycloaddition reaction, etc. The advantages and limitations of this nanocatalyst are also demonstrated. The present study aims to highlight the recent multifaceted applications of ZnO towards the synthesis of diverse heterocyclic motifs. Being a promising biocompatible nanoparticle, this catalyst has an important contribution in the fields of synthetic chemistry and medicinal chemistry.

Natural products as new antimitotic compounds for anticancer drug development

Cell cycle control genes are frequently mutated in cancer cells, which usually display higher rates of proliferation than normal cells. Dysregulated mitosis leads to genomic instability, which contributes to tumor progression and aggressiveness. Many drugs that disrupt mitosis have been studied because they induce cell cycle arrest and tumor cell death. These antitumor compounds are referred to as antimitotics. Vinca alkaloids and taxanes are natural products that target microtubules and inhibit mitosis, and their derivatives are among the most commonly used drugs in cancer therapy worldwide. However, severe adverse effects such as neuropathies are frequently observed during treatment with microtubule-targeting agents. Many efforts have been directed at developing improved antimitotics with increased specificity and decreased likelihood of inducing side effects. These new drugs generally target specific components of mitotic regulation that are mainly or exclusively expressed during cell division, such as kinases, motor proteins and multiprotein complexes. Such small molecules are now in preclinical studies and clinical trials, and many are products or derivatives from natural sources. In this review, we focused on the most promising targets for the development of antimitotics and discussed the advantages and disadvantages of these targets. We also highlighted the novel natural antimitotic agents under investigation by our research group, including combretastatins, withanolides and pterocarpans, which show the potential to circumvent the main issues in antimitotic therapy.

Comparative evaluation of new dihydropyrimidine and dihydropyridine derivatives perturbing mitotic spindle formation

AIM

The mitotic spindle plays a key role in cell division which makes it an important target in cancer therapy. In the present study the antiproliferative activity of 4-benzyl-5-phenyl-3,4-dihydropyrimidine-2(1H)-thione (1) and its pyridine bioisoster (2) were evaluated and compared with monastrol (MON), the first known cell-permeable small molecule which disrupts bipolar spindle formation by inhibiting Eg5-kinesin activity.

RESULTS

Our data revealed that compound 2 showed higher antiproliferative activity than MON against MCF7 and A375 cell lines and comparable reversible cell cycle inhibition in G2/M phase. However, compound 2 produced distinct phenotype from monoastral spindles, and did not affect Eg5 ATPase activity.

CONCLUSION

The activity of compound 2 may suggest its new promising anticancer mechanism (different than MON), targeting other component required for spindle bipolarity.

Novel pyrimidinic selenourea induces DNA damage, cell cycle arrest, and apoptosis in human breast carcinoma

Novel pyrimidinic selenoureas were synthesized and evaluated against tumour and normal cell lines. Among these, the compound named 3j initially showed relevant cytotoxicity and selectivity for tumour cells. Three analogues of 3j were designed and synthesized keeping in view the structural requirements of this compound. Almost all the tested compounds displayed considerable cytotoxicity. However, 8a, one of the 3j analogues, was shown to be highly selective and cytotoxic, especially for breast carcinoma cells (MCF-7) (IC₅₀ = 3.9 μM). Furthermore, 8a caused DNA damage, inhibited cell proliferation, was able to arrest cell cycle in S phase, and induced cell death by apoptosis in human breast carcinoma cells. Moreover, predictions of pharmacokinetic properties showed that 8a may present good absorption and permeation characteristics for oral administration. Overall, the current study established 8a as a potential drug prototype to be employed as a DNA interactive cytotoxic agent for the treatment of breast cancer.

KIF11 silencing and inhibition induces chromosome instability that may contribute to cancer

Understanding the aberrant pathways that contribute to oncogenesis and identifying the altered genes involved in these pathways is a critical first step to develop effective strategies to better combat cancer. Chromosome instability (CIN) is an aberrant phenotype that occurs in ∼80% of all cancer types and is associated with aggressive tumors, the acquisition of multidrug resistance and poor patient prognosis. Despite these associations however, the aberrant genes and molecular defects underlying CIN remain poorly understood. KIF11 is an evolutionarily conserved microtubule motor protein that functions in centrosome and chromosome dynamics in mitosis. Interestingly, the yeast ortholog of KIF11, namely CIN8 is a CIN gene and thus aberrant KIF11 expression and function is suspected to underlie CIN. In support of this possibility, KIF11 is somatically altered in a large number of cancer types. Using a complementary biochemical and genetic approach we examined whether KIF11 silencing with siRNAs or inhibition with monastrol was able to convert two distinct and karyotypically stable cell lines into karyotypically unstable cell lines. Indeed, quantitative imaging microscopy and flow cytometry revealed that KIF11 silencing induced increases in nuclear areas, micronucleus formation, DNA content and chromosome numbers relative to controls that was also observed following KIF11 inhibition. Collectively, this study identifies and validates KIF11 as an evolutionarily conserved CIN gene, and further suggests that aberrant expression and function may contribute to the pathogenesis of a subset of cancers.

l-proline N-sulfonic acid-functionalized magnetic nanoparticles: a novel and magnetically reusable catalyst for one-pot synthesis of 3,4-dihydropyrimidine-2-(1H)-thiones under solvent-free conditions

Synthesis, characterization and utilization of the l-proline N-sulfonic acid-functionalized magnetic nanoparticles as a novel magnetically reusable acid catalyst for the synthesis of 3,4-dihydropyrimidine-2-[1H]thione derivatives is reported.