Ultrasound Mediated One-Pot, Three Component Synthesis, Docking and ADME Prediction of Novel 5-Amino-2-(4-chlorophenyl)-7-Substituted Phenyl-8,8a-dihydro-7H-(1,3,4)thiadiazolo(3,2-α)pyrimidine-6-carbonitrile Derivatives as Anticancer Agents

Exploring the Antiproliferative Potency of Pyrido[2,3-d]Pyrimidine Derivatives: Studies on Design, Synthesis, Anticancer Evaluation, SAR, Docking, and DFT Calculations

Herein, an efficient method for the synthesis of a new series of pyrido[2,3-d]pyrimidine derivatives has been adopted through the reaction of hydrazinyl pyrido[2,3-d] pyrimidine derivative (1) with different electrophilic species, such as ethyl cyanoacetate and different 1,3 diketone derivatives, gave the corresponding derivatives (2-5). Meanwhile, pyrido[2,3-d][1,2,4]triazolo[4,3-a]pyrimidines (6-11) were synthesized via reaction of hydrazine derivative 1 with phenylisothiocyanate, potassium thiocyanate, and carbon disulfide. Compound 1 was also submitted to react with different carbonyl compounds to afford pyrido-pyrimidine derivatives (12-15). All the newly synthesized compounds were tested in vitro for their antiproliferative activities against HCT-116 and MCF-7 cell lines. Compounds 2, 3, 7, and 8 displayed very strong inhibitory activity against the two cell lines compared with the standard drug doxorubicin. Furthermore, a docking study of the most active compounds was performed with the thymidylate synthase enzyme (PDB: Code 6qxg). Moreover, DFT calculation was carried out for the most biologically active compounds and a reference drug (Doxorubicin) using the B3LYP/6-31G+(d,p) level of theory. The calculated EHOMO and ELUMO energies were used to calculate the global reactivity parameters. Finally, Molecular electrostatic potential (MEP) and structure activity relationship (SAR) were studied to correlate the relation between chemical structure and reactivity.

Recent developments using malononitrile in ultrasound-assisted multicomponent synthesis of heterocycles

Ultrasonic irradiation serves as a vigorous and environmentally sustainable approach for augmenting multicomponent reactions (MCRs), offering benefits such as thermal enhancement, agitation, and activation, among others. Malononitrile emerges as a versatile reagent in this context, participating in a myriad of MCRs to produce structurally diverse heterocyclic frameworks. This review encapsulates the critical role of malononitrile in the sonochemical multicomponent synthesis of these heterocyclic structures. The paper further delves into the biochemical and pharmacological implications of these heterocycles, elucidating their reaction mechanisms as well as delineating the method's scope and limitations. We furnish an overview of the merits and challenges inherent to this synthetic approach and offer insights for potential avenues in future research.

Biological Evaluation of Anti-Cholinesterase Activity, in Silico Molecular Docking Studies, and DFT Calculations of Green Synthesized Thiadiazolo[3,2-a]pyrimidine Derivatives

A series of [1,3,4] thiadiazolo[3,2-a]pyrimidine-6-carboxylate derivatives 4(a-n) have been designed and synthesized as inhibitors of acetylcholinesterase (AChE). Synthesizing of thiadiazolo[3,2-a] pyrimidines was carried out in a single step, one-pot reaction using aromatic aldehydes, ethyl acetoacetate and different derivatives of 1,3,4-thiadiazoles (with molar ratio of 1 : 2 : 1, respectively) in conjunction with the catalyst, anhydrous iron(III) chloride by a grinding method under solvent-free conditions at room temperature. The in-vitro studies exhibited good potency for inhibiting AChE comparable with donepezil as the reference drug. The best results were obtained by Ethyl 2-(4-nitroophenyl)-7-methyl-5-(pyridin-3-yl)-5H-[1,3,4]thiadiazolo[3,2-a]pyrimidine-6-carboxylate 4n with IC50 value of 0.082±0.001 μM which was comparable with AChE inhibitory effects of donepezil (IC50 =0.079 μM).

Recent Advances in the Green Synthesis of Active N-Heterocycles and Their Biological Activities

N-heterocyclic scaffolds represent a privileged architecture in the process of drug design and development. It has widespread occurrence in synthetic and natural products, either those that are established or progressing as potent drug candidates. Additionally, numerous novel N-heterocyclic analogues with remarkable physiological significance and extended pharmaceutical applications are escalating progressively. Hence, the classical synthetic protocols need to be improvised according to modern requirements for efficient and eco-friendly approaches. Numerous methodologies and technologies emerged to address the green and sustainable production of various pharmaceutically and medicinally important N-heterocyclic compounds in last few years. In this context, the current review unveils greener alternatives for direct access to categorically differentiated N-heterocyclic derivatives and its application in the establishment of biologically active potent molecules for drug design. The green and sustainable methods accentuated in this review includes microwave-assisted reactions, solvent-free approaches, heterogeneous catalysis, ultrasound reactions, and biocatalysis.

Biological Activity of Two Anticancer Pt Complexes with a Cyclohexylglycine Ligand against a Colon Cancer Cell Line: Theoretical and Experimental Study

Because of their extraordinary ability to disrupt the natural structure of nucleic acids, metal complexes could be used in cancer therapy. In this study, cyclohexylglycine (HL) as a ligand and two new Pt complexes, [Pt(NH₃)₂(L)]NO₃ (1) and [Pt(bipy)(L)]NO₃ (2), were synthesized and characterized by elemental analysis, LC-MS, UV-vis spectrometry, FT-IR, ¹H NMR spectroscopy, ¹³C NMR spectroscopy, ¹⁹⁵Pt NMR spectroscopy, HPLC analysis, and single-crystal X-ray diffraction. Complex 2 crystallized in the orthorhombic Pbca space group, and density functional theory (DFT) was used to describe its structural parameters were described in detail. These complexes can be classified as oral medications and drug-like molecules based on a comparison of their absorption, distribution, metabolism, and excretion assessment. Quantum chemical descriptors (QCDs) were determined using DFT calculations to predict the tendency of DNA to approach these complexes. During the determination of the function of the metallodrug in DNA binding, the fluorescence data indicated that static quenching took place for all ligands and complexes with higher DNA binding affinity. CD and isothermal absorption studies indicate the presence of electrostatic and groove binding for the amine derivative and that DNA binds with the bipy moiety via groove binding. Furthermore, the interaction modes were determined using molecular docking to investigate the binding of these compounds with the target DNA molecule. According to docking investigations, binding energies of -5.7, -11.56, and -10.00 kcal/mol for HL and complexes 1 and 2, respectively, indicate partially electrostatic and groove binding. The anticancer activities of the Pt(II) complexes were tested against the HCT116 human colon cancer cell line, with IC₅₀ values of 35.51 and 51.33 μM for 1 and 2, respectively, after 72 h. These values show that the inhibitory effect of complex 1 was better than those of 2 and carboplatin (IC₅₀ = 51.94 μM).

Synthetic enamine naphthoquinone derived from lawsone as cytotoxic agents assessed by in vitro and in silico evaluations

We synthesized ten enamine naphthoquinones with yields ranging from 43 to 76%. These compounds were screened for their in vitro antiproliferative activities by MTT assay against four types of human cancer cell lines: HCT116, PC3, HL60 and SNB19. The naphthoquinones bearing the picolylamine (7) and quinoline (12) moieties were the most actives (IC₅₀ < 24 μM for all the cell lines), which were comparable or better to the values obtained for the control drugs. In silico evaluations allowed us to develop a qualitative Structure-Activity Relationship which suggest that electrostatic features, particularly the C₂-C₃ internuclear repulsion and the molecular dipole moment, relate to the biological response. Furthermore, Molecular Docking simulations indicate that the synthetic compounds have the potential to act as anticancer molecules by inhibiting topoisomerase-II and thymidylate synthase.

Ultrasound-assisted synthesis of pyrimidines and their fused derivatives: A review

The pyrimidine scaffold is present in many bioactive drugs; therefore, efficient synthetic routes that provide shorter reaction times, higher yields, and site-selective reactions are constantly being sought. Ultrasound (US) irradiation has emerged as an alternative energy source in the synthesis of these heterocyclic scaffolds, and over the last ten years there has been a significant increase in the number of publications mentioning US in either the construction or derivatization of the pyrimidine core. This review presents a detailed summary (with 140 references) of the effects of US (synergic or not) on the construction and derivatization of the pyrimidine core through classical reactions (e.g., multicomponent, cyclocondensation, cycloaddition, and alkylation reactions). The main points that were taken into consideration are as follows: chemo- and regioselectivity issues, and the results of conventional heating methods compared to US and mechanistic insights that are also presented and discussed for key reactions.

Combinational therapeutics to combat cancer

Mono-therapeutics is rarely effective as a treatment option, which limits the survival of patients in advanced grade aggressive cancers. Combinational therapeutics (multiple drugs for multiple targets) to combat cancer is gaining momentum in recent years. Hence, it is of interest to document known data for combinational therapeutics in cancer treatment. An amalgamation of therapeutic agents enhances the efficacy and potency of the therapy. Combinational therapy can potentially target multiple pathways that are necessary for the cancer cells to proliferate, and/or target molecules, which may help cancer to become more aggressive and metastasize. In this review, we discuss combinational therapeutics, which include human γδ T cells in combinations with biologically active anti-cancer molecules, which synergistically may produce promising combinational therapeutics.

N-Benzylation of 6-aminoflavone by reductive amination and efficient access to some novel anticancer agents via topoisomerase II inhibition

Series of novel N-benzyl derivatives of 6-aminoflavone (9a-n) were synthesized and evaluated for anticancer and topoisomerase II enzyme inhibition activity. All the synthesized compounds were screened for in vitro anticancer activity against human breast cancer cell line (MCF-7) and human lung cancer cell line (A-549). Among the synthesized compounds, 9f and 9g were found to be the most potent anticancer agents against human breast cancer cell line (MCF-7) with IC₅₀ values of 9.35 µM and 9.58 µM, respectively. Compounds 9b, 9c and 9n exhibited promising anticancer activity against human lung cancer cell line (A-549) with 43.71%, 46.48% and 44.26% inhibition at the highest concentration of 10 µM, respectively. Compounds 9c, 9f and 9g have ability to inhibit the topoisomerase II enzyme. Compound 9f showed most potent topoisomerase II enzyme inhibition activity with IC₅₀ value of 12.11 µM. Further, these compounds have a high potential to be developed as a promising topoisomerase II inhibitors.

Synthesis of Biologically Active Molecules through Multicomponent Reactions

Focusing on the literature progress since 2002, the present review explores the highly significant role that multicomponent reactions (MCRs) have played as a very important tool for expedite synthesis of a vast number of organic molecules, but also, highlights the fact that many of such molecules are biologically active or at least have been submitted to any biological screen. The selected papers covered in this review must meet two mandatory requirements: (1) the reported products should be obtained via a multicomponent reaction; (2) the reported products should be biologically actives or at least tested for any biological property. Given the diversity of synthetic approaches utilized in MCRs, the highly diverse nature of the biological activities evaluated for the synthesized compounds, and considering their huge structural variability, much of the reported data are organized into concise schemes and tables to facilitate comparison, and to underscore the key points of this review.

Green synthesis and characterisation of novel [1,3,4]thiadiazolo/benzo[4,5]thiazolo[3,2-a]pyrimidines via multicomponent reaction using vanadium oxide loaded on fluorapatite as a robust and sustainable catalyst

We synthesised materials with different loadings of vanadia on fluorapatite (V₂O₅/FAp), fully characterised their structural properties using various spectral techniques including TEM, BET, XRD, FT-IR, SEM and EDX and assessed their prowess as catalysts. The 2.5% V₂O₅/FAp exhibited excellent activity for the synthesis of novel [1,3,4]thiadiazolo[3,2-a]pyrimidines and benzo[4,5]thiazolo[3,2-a]pyrimidines. The one-pot three-component fusion reaction between chosen substrates of 1,3,4-thiadiazole-amines or 2-amino-benzothiazole, aldehydes and active methylene compounds in ethanol solvent at room temperature gave an excellent yield of products (90–97%) in a swift reaction (25–30 min). The advantages of this protocol are rapid synthesis, mild reaction conditions, green solvent, easy work-up, eco-friendliness, reusability of catalyst and no need for column chromatography.

We synthesized material with different loading of vanadia on fluorapatite (V₂O₅/FAp), and excellent activity was showed for the synthesis of pyrimidine derivatives (90–97%) in ethanol medium for short reaction time.

A novel protocol for catalyst-free synthesis of fused six-member rings to triazole and pyrazole

Herein, an effectual, quick and novel method is described for the synthesis of new triazolo[1,5-a]pyrimidine, triazolo[5,1-b][1,3] thiazine and pyrazolo[1,5-a]pyrimidine derivatives. This series of fused six-member rings to triazole and pyrazole was prepared via the catalyst-free reaction of dialkyl acetylenedicarboxylates and 3-substituted 1H-1,2,4-triazole or 3-amino-1H-pyrazole-4-carbonitrile. The structures of the prepared products were deduced from their Fourier-transform infrared, elemental analysis and proton and carbon-13 nuclear magnetic resonance spectral data. A novel and green method is described for the synthesis of new triazolo[1,5-a]pyrimidine, triazolo[5,1-b][1,3] thiazine and pyrazolo[1,5-a]pyrimidine derivatives.

A new efficient domino approach for the synthesis of coumarin-pyrazolines as antimicrobial agents targeting bacteriald-alanine-d-alanine ligase

The inhibition ofd-alanine-d-alanine ligase (Ddl) prevents bacterial growth, which makes this enzyme an attractive and viable target in the urgent search for novel effective antimicrobial drugs.

Ionic Liquid-Promoted Synthesis of Novel Chromone-Pyrimidine Coupled Derivatives, Antimicrobial Analysis, Enzyme Assay, Docking Study and Toxicity Study

Herein, we report an environmentally friendly, rapid, and convenient ionic liquid ([Et₃NH][HSO₄])-promoted facile synthesis of ethyl 4-(6-substituted-4-oxo-4H-chromen-3-yl)-6-methyl-2-thioxo/oxo-1,2,3,4-tetrahydropyrimidine-5-carboxylate derivatives 4(a–f) and 4-(6-substituted-4-oxo-4H-chromen-3-yl)-6-methyl-2-thioxo/oxo-1,2,3,4-tetrahydropyrimidine-5- carbohydrazide derivatives 6(a–f). All the synthesized derivatives 4(a–f) and 6(a–f) were evaluated for their in vitro antifungal and antibacterial activity, by method recommended by National Committee for Clinical Laboratory Standards (NCCLS). The compound 6c bearing a fluoro group on the chromone ring and oxygen and a hydrazino group (–NHNH₂) on the pyrimidine ring, was found to be the most potent antibacterial compound amongst the synthesized derivatives. The compound 6f bearing a methoxy group (–OCH₃) on the chromone ring and sulphur group on the pyrimidine ring, was found to exhibit equipotent antifungal activity when compared with the standard drug miconazole. A d-alanine-d-alanine ligase (DdlB) enzyme assay study and an ergosterol extraction and quantitation assay study were performed to predict the mode of action of the synthesized compounds. A molecular docking study was performed to predict the binding interactions with receptors and mode of action of the synthesized derivatives. Further, analysis of the ADMET parameters for the synthesized compounds has shown that these compounds have good oral drug-like properties and can be developed as oral drug candidates. To establish the antimicrobial selectivity and safety, the most active compounds 6c and 6f were further tested for cytotoxicity against the human cancer cell line HeLa and were found to be non-cytotoxic in nature. An in vivo acute oral toxicity study was also performed for the most active compounds 6c and 6f and the results indicated that the compounds are non-toxic in nature.

Ionic Liquid-Catalyzed Green Protocol for Multi-Component Synthesis of Dihydropyrano[2,3-c]pyrazoles as Potential Anticancer Scaffolds

A series of 6-amino-4-substituted-3-methyl-2,4-dihydropyrano[2,3-c]pyrazole-5-carbonitriles 5a-j were synthesized via one-pot, four-component condensation reactions of aryl aldehydes 1a-j, propanedinitrile (2), hydrazine hydrate (3) and ethyl acetoacetate (4) under solvent-free conditions. We report herein the use of the Brønsted acid ionic liquid (BAIL) triethylammonium hydrogen sulphate [Et₃NH][HSO₄] as catalyst for this multi-component synthesis. Compared with the available reaction methodology, this new method has consistent advantages, including excellent yields, a short reaction time, mild reaction conditions and catalyst reusability. Selected synthesized derivatives were evaluated for in vitro anticancer activity against four human cancer cell lines viz. melanoma cancer cell line (SK-MEL-2), breast cancer cell line(MDA-MB-231), leukemia cancer cell line (K-562) and cervical cancer cell line (HeLa). Compounds 5b, 5d, 5g, 5h and 5j exhibited promising anticancer activity against all selected human cancer cell lines, except HeLa. Molecular docking studies also confirmed 5b and 5d as good lead molecules. An in silico ADMET study of the synthesized anticancer agents indicated good oral drug-like behavior and non-toxic nature.

Facile Synthesis of Novel Coumarin Derivatives, Antimicrobial Analysis, Enzyme Assay, Docking Study, ADMET Prediction and Toxicity Study

The work reports the synthesis under solvent-free condition using the ionic liquid [Et₃NH][HSO₄] as a catalyst of fifteen novel 3-((dicyclohexylamino)(substituted phenyl/heteryl)-methyl)-4-hydroxy-2H-chromen-2-onederivatives 4a-o as potential antimicrobial agents. The structures of the synthesized compounds were confirmed by IR, ¹H-NMR, ¹³C-NMR, mass spectral studies and elemental analyses. All the synthesized compounds were evaluated for their in vitro antifungal and antibacterial activity. The compound 4k bearing 4-hydroxy-3-ethoxy group on the phenyl ring was found to be the most active antifungal agent. The compound 4e bearing a 2,4-difluoro group on the phenyl ring was found to be the most active antibacterial agent. The mode of action of the most promising antifungal compound 4k was established by an ergosterol extraction and quantitation assay. From the assay it was found that 4k acts by inhibition of ergosterol biosynthesis in C. albicans. Molecular docking studies revealed a highly spontaneous binding ability of the tested compounds to the active site of lanosterol 14α-demethylase, which suggests that the tested compounds inhibit the synthesis of this enzyme. The synthesized compounds were analyzed for in silico ADMET properties to establish oral drug like behavior and showed satisfactory results. To establish the antimicrobial selectivity and safety, the most active compounds 4e and 4k were further tested for cytotoxicity against human cancer cell line HeLa and were found to be non-cytotoxic in nature. An in vivo acute oral toxicity study was also performed for the most active compounds 4e and 4k and results indicated that the compounds are non-toxic.