Aminopyrimidines: Recent synthetic procedures and anticancer activities

Design, synthesis, inhibitory activity, and molecular simulations study for d-glucose-conjugated thioureas containing pyrimidine ring as multitarget inhibitors against α-amylase, α-glucosidase, DDP-4, and PTP1B in Type 2 diabetes mellitus

A series of tetra-O-acetyl-α-d-glucopyranosyl thioureas 8a-l of substituted 2-aminopyrimidines 4a-l have been designed and synthesized. The latter were prepared from corresponding chalcones 3a-l of p-bromoacetophenone and appropriate substituted benzaldehydes by their reaction with guanidine. The target thiourea compounds 8a-l exhibited significant inhibitory activity in vitro against enzymes that were related to type 2 diabetes mellitus, including α-amylase, α-glucosidase, DPP-4, and PTP1B. Amongst these thioureas, compound 8k with an ortho-methoxy group was the most potential enzyme inhibitor against α-amylase with an IC50 value of 9.72 ± 0.34 μM. Its meta-isomer 8j was the strongest inhibitor against α-glucosidase with IC50 = 9.73 ± 0.72 μM. In the inhibition against DPP-4, compound 8f with a para-bromo substituent exhibited the strongest activity with an IC50 value of 2.53 ± 0.03 nM. In the inhibition against PTP1B, compound 8h with a para-isopropyl substituent had the strongest inhibitory activity with an IC50 value of 2.74 ± 0.03 μM. The enzyme kinetics of the most active compounds, including 8j, 8f and 8h against α-glucosidase, DPP-4, and PTP1B, respectively, were studied. The obtained results showed that 8j was a competitive α-glucosidase inhibitor with an inhibitory constant K I value of 9.31 μM. Compound 8f was a non-competitive inhibitor for DDP-4 with an inhibitory constant K I value of 12.57 μM. Compound 8h was also a non-competitive inhibitor for DDP-4 with an inhibitory constant K I value of 12.41 μM. The cytotoxicity of the most active compounds, including 8f and 8k (against α-amylase), 8i and 8j (against α-glucosidase), 8a, 8f, and 8g (against DPP-4), and 8d, 8f, and 8h (against PTP1B) was screened. The obtained cytotoxicity showed that all tested inhibitors were noncytotoxic to human normal cell line 3T3. Induced fit docking simulations of all synthesized compounds 8a-l were performed on four enzymes 4W93 (for α-amylase), 3TOP (for α-glucosidase), 3W2T (for DPP-4), and 1NNY (for PTP1B). Key interactions of each of these ligands with residues in the active pocket of each studied enzyme have been shown.

A polyurethane-based hydrophilic elastomer with multi-biological functions for small-diameter vascular grafts

Thrombosis and intimal hyperplasia (IH) are two major problems faced by the small-diameter vascular grafts. Mimicking the native endothelium and physiological elasticity of blood vessels is considered an ideal strategy. Polyurethane (PU) is suitable for vascular grafts in mechanics because of its molecular designability and elasticity; however, it generally lacks the endothelium-like biofunctions and hydrophilicity. To solve this contradiction, a hydrophilic PU elastomer is developed by crosslinking the hydrophobic hard-segment chains containing diselenide with diaminopyrimidine-capped polyethylene glycol (PEG). In this network, the hydrophobic aggregation occurs underwater due to the uninterrupted hard-segment chains, leading to a significant self-enhancement in mechanics, which can be tailored to the elasticity similar to natural vessels by adjusting the crosslinking density. A series of in vitro studies confirm that the hydrophilicity of PEG and biological activities of aminopyrimidine and diselenide give the PU multi-biological functions similar to the native endothelium, including stable catalytic release of nitric oxide (NO) in the physiological level; anti-adhesion and anti-activation of platelets; inhibition of migration, adhesion, and proliferation of smooth muscle cells (SMCs); and antibacterial effect. In vivo studies further prove the good histocompatibility with both significant reduction in immune response and calcium deposition. STATEMENT OF SIGNIFICANCE: Constructing small-diameter vascular grafts similar to the natural vessels is considered an ideal method to solve the restenosis caused by thrombosis and intimal hyperplasia (IH). Because of the long-term stability, bulk modification is more suitable for implanted materials, however, how to achieve the biofunctions, hydrophilicity, and elasticity simultaneously is still a big challenge. In this work, a kind of polyurethane-based elastomer has been designed and prepared by crosslinking the functional long hard-segment chains with PEG soft segments. The underwater elasticity based on hydration-induced stiffening and the multi-biological functions similar to the native endothelium are compatible with natural vessels. Both in vitro and in vivo experiments demonstrate the potential of this PU as small-diameter vascular grafts.

Sulfonyl thiourea derivatives from 2-aminodiarylpyrimidines: In vitro and in silico evaluation as potential carbonic anhydrase I, II, IX, and XII inhibitors

A series of synthesized sulfonyl thiourea derivatives (7a-o) of substituted 2-amino-4,6-diarylpyrimidines (4a-o) exhibited the remarkable inhibitory activity against some the human carbonic anhydrases (hCAs), including hCA I, II, IX, and XII isoforms. The inhibitory efficacy of synthesized sulfonyl thiourea derivatives were experimentally validated by in vitro enzymatic assays. 7a (KI  = 46.14 nM), 7j (KI  = 48.92 nM), and 7m (KI  = 62.59 nM) (for isoform hCA I); 7f (KI  = 42.72 nM), 7i (KI  = 40.98 nM), and 7j (KI  = 33.40 nM) (for isoform hCA II); 7j (KI  = 228.5 nM), 7m (KI  = 195.4 nM), and 7n (KI  = 210.1 nM) (for isoform hCA IX); 7l (KI  = 116.9 nM), 7m (KI  = 118.8 nM), and 7n (KI  = 147.2 nM) (for isoform hCA XII) in comparison with KI values of 452.1, 327.3, 437.2, and 338.9 nM, respectively, of the standard drug AAZ. These compounds also had significantly more potent inhibitory action against cytosolic isoform hCA I and tumor-associated isoforms hCA IX and hCA XII. Furthermore, the potential inhibitory compounds were subjected to in silico screening for molecular docking and molecular dynamics simulations. The results of in vitro and in silico studies revealed that compounds 7a, 7j, and 7m were the most promising derivatives in this series due to their significant effects on studied hCA I, II, IX, and XII isoforms, respectively. The results showed that the sulfonyl thiourea moiety was accommodated deeply in the active site and interacted with the zinc ion in the receptors.

Identification of novel aminopyrimidine derivatives for the treatment of mutant NSCLC

Starting from the binding mode of allosteric EGFR inhibitor JBJ-04-125-02 and the key pharmacophore of the third-generation EGFR inhibitors, we designed and synthesized a novel series of EGFR inhibitors, represented by (R)-N-(4-((2-aminopyrimidin-4-yl)amino)phenyl)-2-(5-(4-(4-methylpiperazin-1-yl)phenyl)-1-oxoisoindolin-2-yl)-2-phenylacetamide (6q). Docking study demonstrated that top compound 6q spanned orthosteric and allosteric sites of EGFR, and formed three key H-bonds with the residues Asp855, Lys745, and Met793 located in two sites. Biological evaluation indicated that compound 6q showed potential inhibitory activity against Ba/F3-EGFRL858R/T790M/C797S and Ba/F3-EGFRDel19/T790M/C797S cells, with IC50 values of 0.42 μM and 0.41 μM, respectively. Furthermore, compound 6q showed excellent activity against mutant NSCLC cell line NCI-H1975-EGFRL858R/T790M/C797S cells, with IC50 value of 0.82 μM which was superior to that of osimertinib (IC50 = 2.94 μM), JBJ-04-125-02 (IC50 = 3.66 μM), and coadministration of JBJ-04-125-02 and osimertinib (IC50 = 1.25 μM). Cell cycle arrest and cell apoptosis assay indicated that compound 6q could promote apoptosis of NCI-H1975-EGFRL858R/T790M/C797S cells at the concentration of 0.8 μM and no obvious cell cycle arrest was found.

2-Thioxo-3,4-dihydropyrimidine and thiourea endowed with sulfonamide moieties as dual EGFRT790M and VEGFR-2 inhibitors: Design, synthesis, docking, and anticancer evaluations

The effectiveness of a new series of thiopyrimidine and thiourea containing sulfonamides moieties was tested on HCT-116, MCF-7, HepG2, and A549. HepG2 cell line was the one that all the new derivatives affected the most. The greatest potent compounds against the four HepG2, HCT116, MCF-7, and A549 cell lines were 8f and 8g with IC50  = 4.13, 6.64, 5.74, 6.85 µM and 4.09, 4.36, 4.22, 7.25 µM correspondingly. Compound 8g exhibited higher activity than sorafenib against HCT116 and MCF-7 but exhibited lower activity against HepG2 and A549. Moreover, compounds 8f and 8g exhibited higher activities than erlotinib on HepG2, HCT116, and MCF-7 but demonstrated lower activity on A549. The most potent cytotoxic derivatives 6f, 6g, 8c, 8d, 8e, 8f, and 8g were examined on normal VERO cell lines. Our derivatives have low toxicity on VERO cells with IC50 values ranging from 32.05 to 53.15 μM. Additionally, all compounds were assessed for dual VEGFR-2 and EGFRT790M inhibition effects. Compounds 8f and 8g were the most potent derivatives inhibited VEGFR-2 at IC50 value of 0.88 and 0.90 µM, correspondingly. As well, derivatives 8f and 8g could inhibit EGFRT790M demonstrating strongest effects with IC50  = 0.32 and 0.33 µM sequentially. Additionally, the greatest active derivatives ADMET profile was evaluated in relationship with sorafenib and erlotinib as reference agents. The data attained from docking were greatly related to that achieved from the biological testing.

Transition-metal-free four-component reaction of nitriles and disulfides/diselenides

One-pot synthesis of structurally diverse sulfurized/selenated 4-aminopyrimidines has been reported via t-BuOK/K2S2O8-promoted four-component reaction of mixed nitriles and disulfides/diselenides. Mechanistic studies indicate that the reaction proceeds through radical and ionic pathways, and an alkenyl sulfide serves as a key intermediate.

Synthesis of Polysubstituted Pyrimidines through Palladium-Catalyzed Isocyanide Insertion to 2H-Azirines

The domino process of the palladium-catalyzed coupling reaction of isocyanides with 2H-azirine provides various tetrasubstituted pyrimidines via one C-C bond and two C-N bond formations with satisfactory yields. The title compounds are obtained with good functional group tolerance, high atom economy, and broad substrate scopes.

Catalyzed Methods to Synthesize Pyrimidine and Related Heterocyclic Compounds

This review covers articles published in the period from 2010 to mid-2022 on synthetic advances in the formation of pyrimidine and related heterocyclic compounds. Special emphasis has been given to the different types of cycloadditions, taking into account the number of their components and leading to the formation of the pyrimidine ring. Due to the large number of publications on the Biginelli reaction and related reactions, this will be dealt with in a separate review in the near future.

Synthesis of 2-Aminopyrimidine Derivatives and Their Evaluation as β-Glucuronidase Inhibitors: In Vitro and In Silico Studies

Currently the discovery and development of potent β-glucuronidase inhibitors is an active area of research due to the observation that increased activity of this enzyme is associated with many pathological conditions, such as colon cancer, renal diseases, and infections of the urinary tract. In this study, twenty-seven 2-aminopyrimidine derivatives 1-27 were synthesized by fusion of 2-amino-4,6-dichloropyrimidine with a variety of amines in the presence of triethylamine without using any solvent and catalyst, in good to excellent yields. All synthesized compounds were characterized by EI-MS, HREI-MS and NMR spectroscopy. Compounds 1-27 were then evaluated for their β-glucuronidase inhibitory activity, and among them, compound 24 (IC₅₀ = 2.8 ± 0.10 µM) showed an activity much superior to standard D-saccharic acid 1,4-lactone (IC₅₀ = 45.75 ± 2.16 µM). To predict the binding mode of the substrate and β-glucuronidase, in silico study was performed. Conclusively, this study has identified a potent β-glucuronidase inhibitor that deserves to be further studied for the development of pharmaceutical products.

Three-Component Cycloaddition of Nitriles: Construction of Bicyclic 4-Aminopyrimidines and Their Photophysical Studies

A base-induced synthesis of bicyclic 4-aminopyrimidines by the cycloaddition of three types of nitriles is reported. The scope of the method is demonstrated with 44 examples. Products are found to have luminescence properties and show potential applications as organic luminescent layer materials.

Synthesis and HDAC inhibitory activity of pyrimidine-based hydroxamic acids

Histone deacetylases (HDACs) play an essential role in the transcriptional regulation of cells through the deacetylation of nuclear histone and non-histone proteins and are promising therapeutic targets for the treatment of various diseases. Here, the synthesis of new compounds in which a hydroxamic acid residue is attached to differently substituted pyrimidine rings via a methylene group bridge of varying length as potential HDAC inhibitors is described. The target compounds were obtained by alkylation of 2-(alkylthio)pyrimidin-4(3H)-ones with ethyl 2-bromoethanoate, ethyl 4-bromobutanoate, or methyl 6-bromohexanoate followed by aminolysis of the obtained esters with hydroxylamine. Oxidation of the 2-methylthio group to the methylsulfonyl group and following treatment with amines resulted in the formation of the corresponding 2-amino-substituted derivatives, the ester group of which reacted with hydroxylamine to give the corresponding hydroxamic acids. The synthesized hydroxamic acids were tested as inhibitors of the HDAC4 and HDAC8 isoforms. Among the synthesized pyrimidine-based hydroxamic acids N-hydroxy-6-[6-methyl-2-(methylthio)-5-propylpyrimidin-4-yloxy]hexanamide was found to be the most potent inhibitor of both the HDAC4 and HDAC8 isoforms, with an IC50 of 16.6 µM and 1.2 µM, respectively.

2-Aminopyrimidinium Decavanadate: Experimental and Theoretical Characterization, Molecular Docking, and Potential Antineoplastic Activity

The interest in decavanadate anions has increased in recent decades, since these clusters show interesting applications as varied as sensors, batteries, catalysts, or new drugs in medicine. Due to the capacity of the interaction of decavanadate with a variety of biological molecules because of its high negative charge and oxygen-rich surface, this cluster is being widely studied both in vitro and in vivo as a treatment for several global health problems such as diabetes mellitus, cancer, and Alzheimer’s disease. Here, we report a new decavanadate compound with organic molecules synthesized in an aqueous solution and structurally characterized by elemental analysis, infrared spectroscopy, thermogravimetric analysis, and single-crystal X-ray diffraction. The decavanadate anion was combined with 2-aminopyrimidine to form the compound [2-ampymH]6[V10O28]·5H2O (1). In the crystal lattice, organic molecules are stacked by π–π interactions, with a centroid-to-centroid distance similar to that shown in DNA or RNA molecules. Furthermore, computational DFT calculations of Compound 1 corroborate the hydrogen bond interaction between pyrimidine molecules and decavanadate anions, as well as the π–π stacking interactions between the central pyrimidine molecules. Finally, docking studies with test RNA molecules indicate that they could serve as other potential targets for the anticancer activity of decavanadate anion.

Mechanochemical Magnesium-Mediated Minisci C-H Alkylation of Pyrimidines with Alkyl Bromides and Chlorides

A novel method to synthesize 4-alkylpyrimidines by the mechanochemical magnesium-mediated Minisci reaction of pyrimidine derivatives and alkyl halides has been reported. The reaction process operates with a broad substrate scope and excellent regioselectivity under mild conditions with no requirement of transition-metal catalysts, solvents, and inert gas protection. The practicality of this protocol has been demonstrated by the up-scale synthesis, mechanochemical product derivatization, and antimalarial drug pyrimethamine preparation.