One-pot synthesis and in vivo biological evaluation of new pyrimidine privileged scaffolds as potent anti-inflammatory agents

New Diaryl-1,2,4-triazolo[3,4-a]pyrimidine Hybrids as Selective COX-2/sEH Dual Inhibitors with Potent Analgesic/Anti-inflammatory and Cardioprotective Properties

COX-2-selective drugs were withdrawn from the market just a few years after their development due to cardiovascular side effects. As a result, developing a selective COX-2 inhibitor as an anti-inflammatory agent with cardioprotective characteristics has become a prominent objective in medicinal chemistry. New 15 diaryl-1,2,4-triazolo[3,4-a]pyrimidine hybrids 8a-o were synthesized and investigated in vitro as dual COX-2/sEH inhibitors. Compounds 8b, 8m, and 8o have the highest potency and selectivity as COX-2 inhibitors (IC50 = 15.20, 11.60, and 10.50 μM, respectively; selectivity index (COX-1/COX-2) = 13, 20, and 25, respectively), compared to celecoxib (COX-2; IC50 = 42 μM; SI = 8). The 5-LOX inhibitory activity of compounds 8b, 8m, and 8o was further examined in vitro. Compounds 8m and 8o, the most effective COX-2 selective inhibitors, demonstrated stronger 5-LOX inhibitory action than the reference quercetin, with IC50 values of 2.90 and 3.05 μM, respectively. Additionally, compounds 8b, 8m, and 8o were the most potent dual COX-2/sEH inhibitors, with IC50 values against sEH of 3.20, 2.95, and 2.20 nM, respectively, and were equivalent to AUDA (IC50 = 1.2 nM). In vivo investigations also demonstrated that these compounds were the most efficacious as analgesic/anti-inflammatory derivatives with a high cardioprotective profile against cardiac biomarkers and inflammatory cytokines. The docking data analysis inquiry helped better understand the binding mechanisms of the most active hybrids within the COX-2 active site and supported their COX-2 selectivity. Compounds 8b, 8m, and 8o exhibited a similar orientation to rofecoxib and celecoxib, with a larger proclivity to enter the selectivity side pocket than the reference compounds.

Design, synthesis, and biological evaluation of new pyrimidine-5-carbonitrile derivatives as novel anti-cancer, dual EGFRWT/COX-2 inhibitors with docking studies

A novel series of pyrimidine-5-carbonitrile derivatives was designed, synthesized, then evaluated for their cytotoxic activity as novel anti-cancer with dual EGFRWT/COX-2 inhibitors. Two compounds 4e and 4f disclosed the highest activity against all NCI60 panel cell lines. They were most potent against Colo 205 (IC50 = 1.66, and 1.83 μM), Sequentially. The most potent two compounds disturbed cell cycle of Colo-205 cells by blocking the G1 phase, coupled with increased annexin-Vstained cells which indicated the increasing in percentage of apoptosis. In addition, 4e and 4f increase the concentration of caspase-3 by 10, and 8-fold compared to control, respectively. Moreover, the two candidate compounds were screened for cytotoxicity on normal epithelial colon cells; fortunately, they were found to be safe. Molecular docking study displayed that these compounds bound to the active site as EGFRWT/COX-2 inhibitors. Furthermore, 3D pharmacophore mapping disclosed many shared features between the most potent candidates 4e and 4f and the standard EGFRWT/COX-2 inhibitors; erlotinib, and celecoxib, respectively. Finally, the physicochemical parameter was calculated for the most potent novel anticancer candidates and the SwissAdme parameter showed that the newly synthesized compounds have good drug-likeness properties.

Conjugates of Lupane Triterpenoids with Arylpyrimidines: Synthesis and Anti-inflammatory Activity

Semisynthetic triterpenoid betulonic acid is of significant interest due to its biological activity and synthetic application. In this study, we report the synthesis of hybrid compounds, containing betulonic acid carboxamide and arylpyrimidine fragments. A total of 15 conjugates were prepared using the cyclocondensation reaction of new terpenoid alkynyl ketones with amidinium salts. The main synthetic approach to betulonic acid amide-derived alkynylketones was based on the cross-coupling reaction of N-(4-ethynylphenyl)- or N-(2-(4-ethynylphenyl)-1-(methoxycarbonyl)ethyl)- substituted betulonic acid carboxamide with aroylchlorides. Cyclocondensation of alkynones with amidine or guanidine hydrochlorides by reflux in MeCN in the presence of K₂CO₃ led to the formation of terpenoid pyrimidine hybrids in 52-89% isolated yield. Anti-inflammatory properties of new type of triterpenoid-pyrimidine conjugates were studied using the histamine- and concanavalin A- induced mouse paw edema models. In a model of acute inflammation betulonic acid amide-arylpyrimidines containing a 4-fluorophenyl substituent at the C-6 position of pyrimidine ring exhibited significant and selective anti-inflammatory activity. Compounds containing the 4-bromophenyl- substituent in the pyrimidine ring revealed selective anti-inflammatory activity in the model of immunogenic inflammation (concanavalin-A model). It should be noted that the methoxycarbonyl substituted ethane link between pharmacophore ligands (betulonic acid carboxamide and arylpyrimidine) has a significant effect on anti-inflammatory activity in both in vivo models of inflammation. It was shown by molecular docking that the new derivatives are incorporated into the binding site of the protein Keap1 Kelch-domain by their pyrimidine substituent with the formation of more non-covalent bonds.

Design, synthesis, and biological evaluation of new pyrimidine-5-carbonitrile derivatives bearing 1,3-thiazole moiety as novel anti-inflammatory EGFR inhibitors with cardiac safety profile

A new series of pyrimidine-5-carbonitrile derivatives 8a-p carrying the 1,3-thiazole moiety has been designed and synthesized as novel anti-inflammatory EGFR inhibitors with cardiac and gastric safety profiles. 8a-p have been assessed for their inhibitory activity against COX-1/COX-2 activity. Compounds 8h, 8n, and 8p were found to be potent and selective COX-2 inhibitors (IC₅₀ = 1.03-1.71 μM) relative to celecoxib (IC₅₀ = 0.88 μM). The most potent COX-2 inhibitors have been further investigated for their in-vivo anti-inflammatory effect. Compounds 8h, 8n, and 8p showed anti-inflammatory activity up to 90%, 94% and 86% of meloxicam after 4 h interval. 8h, 8n, and 8p showed higher gastric safety profiles than meloxicam. A substantial reduction in serum concentrations of PGE₂, TNF-α, IL-6, iNO and MDA and a significant induction of TAC was also observed. In vivo experiments on heart rate and blood pressure established the cardiovascular safety profile of 8h, 8n, and 8p. Anti-proliferative and wild-type EGFR inhibitory assays displayed similar results to selective COX-2 inhibition where compounds 8h, 8n, and 8p had a superior inhibition than other tested ones. Molecular docking study demonstrated that these compounds revealed similar orientation and binding interactions as selective COX-2 inhibitors with a higher liability to enter the side pocket selectively. Also, they interacted with EGFR tyrosine kinase main amino acids similar to erlotinib with a strong binding energy score.

Design and synthesis of pyrimidine-5-carbonitrile hybrids as COX-2 inhibitors: Anti-inflammatory activity, ulcerogenic liability, histopathological and docking studies

Two new series of 1,3,4-oxadiazole and coumarin derivatives based on pyrimidine-5-carbonitrile scaffold have been synthesized and evaluated for their COX-1/COX-2 inhibitory activity. Compounds 10c, 10e, 10h-j, 14e-f, 14i and 16 were found to be the most potent and selective inhibitors of COX-2 (IC₅₀ 0.041-0.081 μM, SI 139.74-321.95). Eight compounds were further investigated for their in vivo anti-inflammatory activity. The most active derivatives 10c, 10j and 14e displayed superior in vivo anti-inflammatory activity (% edema inhibition 39.3-48.3, 1 h; 58.4-60.5, 2 h; 70.8-83.2, 3 h; 78.9-89.5, 4 h) to the reference drug celecoxib (% edema inhibition 38.0, 1 h; 48.8, 2 h; 58.4, 3 h; 65.4, 4 h). These derivatives were also tested for their ulcerogenic liability, compound 10j showed better safety profile with reference to celecoxib while 10c and 14e exhibited mild lesions. Molecular docking studies of 10c, 10j, and 14e in the COX-2 active site revealed similar orientation and binding interactions as selective COX-2 inhibitors with a higher liability to access the selectivity side pocket.