Synthesis of new multitarget-directed ligands containing thienopyrimidine nucleus for inhibition of 15-lipoxygenase, cyclooxygenases, and pro-inflammatory cytokines

A new series of thieno[2,3-d]pyrimidine derivatives 4, 5, 6a-o, and 11 was designed and synthesized starting from cyclohexanone under Gewald condition with the aim to develop multitarget-directed ligands (MTDLs) having anti-inflammatory properties against both 15-LOX and COX-2 enzymes. Moreover, the potential of the compounds against the proinflammatory mediators NO, ROS, TNF-α, and IL-6 were tested in LPS-activated RAW 264.7 macrophages. Compound 6o showed the greatest 15-LOX inhibitory effect (IC₅₀ = 1.17 μM) which was superior to that of the reference nordihydroguaiaretic acid (NDGA, IC₅₀ = 1.28 μM); meanwhile, compounds 6h, 6g, 11, and 4 exhibited potent activities (IC₅₀ = 1.29-1.77 μM). The ester 4 (SI = 137.37) and the phenyl-substituted acetohydrazide 11 (SI = 132.26) showed the highest COX-2 selectivity, which was about 28 times more selective than the reference drug diclofenac (SI = 4.73), however, it was lower than that of celecoxib (SI = 219.25). Interestingly, compound 6o, which showed the highest 15-LOX inhibitory activity and 5 times higher COX-2 selectivity than diclofenac, showed a greater poteny in reducing NO (IC₅₀ = 7.77 μM) than both celecoxib (IC₅₀ = 22.89 μM) and diclofenac (IC₅₀ = 25.34), but comparable activity in inhibiting TNF-α (IC₅₀ = 11.27) to diclofenac (IC₅₀ = 10.45 μM). Similarly, compounds 11 and 6h were more potent in reducing TNF-α and IL6 levels than diclofenac, meanwhile, compound 4 reduced ROS, NO, IL6, and TNF-α levels with comparable potency to the reference drugs celecoxib and diclofenac. Furthermore, docking studies for our compounds within 15-LOX and COX-2 active sites revealed good agreement with the biological evaluations. The proposed compounds could be promising multi-targeted anti-inflammatory candidates to treat resistant inflammatory conditions.

Design, synthesis and antitumor evaluation of novel pyrazolo[3,4-d]pyrimidines incorporating different amino acid conjugates as potential DHFR inhibitors

The present study aimed to investigate the antitumor effect of simultaneous inhibition of dihydrofolate reductase (DHFR) enzyme. We designed some novel pyrazolo[3,4-d]pyrimidines bearing different amino acid conjugates as efficient antifolate agents attributable to their structural similarity with methotrexate (MTX) and MTX-related antifolates. All compounds were tested to screen their enzymatic inhibition against DHFR compared with the reference drug MTX and for their in vitro antitumor cytotoxicity against six MTX-resistant cancer cell lines. The flow cytometry indicated that the most potent compound 7f arrested MCF-7 cells in the S-phase and induced apoptosis. Western blot for visualisation proved the ability of compound 7f to induce the expression of proapoptotic caspases and Bax proteins in MCF-7 breast cancer cell line beside its ability to diminish the expression of antiapoptotic Bcl-2 protein. Molecular modelling studies concluded that compound 7f displayed better binding energy than that of the normal ligand MTX.

HIGHLIGHTS

New pyrazolo[3,4-d]pyrimidine derivatives 7a–m which are structurally similar to the classical methotrexate (MTX) and MTX-related antifolates were synthesised as antitumor agents.

Novel N-acyl amino acid compound 7f exhibited marked DHFR inhibition activity that are parralel to both the molecular docking results and cytotoxic activity.

Compound 7f could induce the expression of proapoptotic caspases and Bax proteins in MCF-7 breast cancer cell line beside its ability to diminish the expression of antiapoptotic Bcl-2 protein.

All prepared compounds obey Lipinski rule of five except compound 7f.

Design, synthesis, and pharmacological evaluation of novel and selective COX-2 inhibitors based on bumetanide scaffold

Herein, we describe the design and synthesis of new benzenesulfonamide derivatives as selective COX-2 inhibitors based on bumetanide scaffold. Benzenesulfonamides bearing both the pyrazole 6b and the triazoles 9a, 9c were good inhibitors of COX-2 with IC50 values of 0.32, 0.28 and 0.17 µM, respectively. These benzenesulfonamides 6b, 9a and 9c exhibited a higher selectivity index than the reference drug celecoxib. Molecular modeling study showed that incorporation of bumetanide led to a unique binding mode that is most likely the reason for the observed significant COX-2 selectivity. The anti-inflammatory activity of synthesized compounds revealed that triazoles 9a and 9c demonstrated higher efficacy than celecoxib upon using in vivo carrageenan-induced rat paw edema model. Most of the prepared compounds possess low ulcerogenic potential when administered orally. Therefore, these compounds have a great potential to be developed as safe therapeutics for inflammation, pain, and other diseases where COX-2 plays important role in their pathophysiology.

Novel benzenesulfonamide and 1,2-benzisothiazol-3(2H)-one-1,1-dioxide derivatives as potential selective COX-2 inhibitors

Two new series of 1,2-benzisothiazol-3(2H)-one-1,1-dioxide derivatives containing either five membered heterocyclic rings or aryl hydrazones were synthesized and evaluated for their in vitro COX-1/COX-2 inhibitory activity. In vivo anti-inflammatory evaluation revealed that benzenesulfonamides bearing pyrazole moiety 19, 20 and its cyclized form 23 exhibited the highest anti-inflammatory activity with comparable potency to celecoxib. Furthermore, the ulcerogenic activity evaluation showed that compounds 19, 20 and 23 exerted the minimal ulcer index in comparison to indomethacin as a reference drug. Docking studies of the most selective COX-2 derivatives were also carried out against COX-2 active site. Benzenesulfonamide derivatives 19 and 20 displayed higher predicted binding affinities inside the COX-2 active site. Molecular modelling simulation and drug likeness studies showed good agreement with the obtained biological evaluation.

Synthesis of some new benzisothiazolone and benzenesulfonamide derivatives of biological interest starting from saccharin sodium

Two new series of benzenesulfonamide (4a-f, 5a-b, 6, 7) and 1,2-benzisothiazol-3(2H)-one-1,1-dioxide (9a-c, 10, 12a-d) derivatives were prepared starting from saccharin sodium. The novel compounds were characterized using elemental analyses and different spectroscopic methods. Assessment of the antiviral activities of these novel compounds against a broad panel of viruses in different cell cultures revealed that only the thiazole derivatives belonging to the benzisothiazol-3(2H)-one-1,1-dioxide series are the active ones. All thiazole derivatives 12a-d showed activity against both varicella-zoster virus, especially TK(-) VZV strain 07-1, and the cytomegalovirus strains AD-169 and Davis in human embryonic lung (HEL) cell culture.

Synthesis and biological evaluation of some N-arylpyrazoles and pyrazolo[3,4-d]pyridazines as anti-inflammatory agents

A series of 3,4-bis-chalcone-N-arylpyrazoles 3a-k was prepared from diacetyl pyrazoles 2a-e. The reaction of 2d and 2e with hydrazine hydrate gave pyrazolo[3,4-d]pyridazine derivatives 4a-b. Furthermore, the reaction of 2a-e with thiosemicarbazide afforded pyrazolo[3,4-d]pyridazine thiocyanate salts 5a-e. The synthesized compounds were subjected to in vivo anti-inflammatory and ulcerogenic activity measurements, in addition to determination of their in vitro COX selectivity, to give a full profile about their anti-inflammatory activities. Compounds 3c, 3f, 3i, and 3e showed significant anti-inflammatory activity among the synthesized compounds. Moreover, docking studies were performed to give an explanation for their anti-inflammatory activity through COX selectivity.

Synthesis of new 2,3-dihydroquinazolin-4(1H)-one derivatives for analgesic and anti-inflammatory evaluation

Starting from isatoic anhydrides, several new 2,3-dihydroquinazolin-4(1H)-one derivatives bearing chalcone or pyrazole or thiazole moieties at the third position were synthesized. The analgesic and anti-inflammatory activities for most compounds were studied at a dose level of 50 mg/kg via the acetic-acid-induced writhing-response method and carrageenan-induced edema method, respectively. The study showed that the chalcones bearing a 4-chlorophenyl group 4c or 4-nitrophenyl group 4b were the most active ones as analgesics. Both chalcone 4c and N-phenyl pyrazole bearing 4-methoxy phenyl group 5b showed a higher anti-inflammatory activity than celecoxib but still lower than that of diclofenac sodium. Moreover, the chalcone 4c has nearly the same ulcerogenic index as the selective cyclooxygenase-2 inhibitor celecoxib.

Synthesis of new 2,3-dihydroquinazolin-4(1H)-one derivatives for analgesic and anti-inflammatory evaluation

Starting from isatoic anhydrides, several new 2,3-dihydroquinazolin-4(1H)-one derivatives bearing chalcone or pyrazole or thiazole moieties at the third position were synthesized. The analgesic and anti-inflammatory activities for most compounds were studied at a dose level of 50 mg/kg via the acetic-acid-induced writhing-response method and carrageenan-induced edema method, respectively. The study showed that the chalcones bearing a 4-chlorophenyl group 4c or 4-nitrophenyl group 4b were the most active ones as analgesics. Both chalcone 4c and N-phenyl pyrazole bearing 4-methoxy phenyl group 5b showed a higher anti-inflammatory activity than celecoxib but still lower than that of diclofenac sodium. Moreover, the chalcone 4c has nearly the same ulcerogenic index as the selective cyclooxygenase-2 inhibitor celecoxib.

Synthesis, DNA Binding and Antiviral Activity of New Uracil, Xanthine, and Pteridine Derivatives

Some new 6-amino-1,3-dimethyl-5-(substituted methylidene)aminouracils were synthesized. Most of them were cyclized with triethyl orthoformate as a one-carbon source to afford 1,3-dime-thyl-6-substituted pteridine derivatives. Certain uracils gave xanthine instead of the expected pteridine derivatives upon using another one-carbon source such as triethyl orthoacetate or triethyl orthobenzoate. The nucleic acid binding assay revealed that some new compounds showed high affinity, chelation, and fragmentation of nucleic acids whether DNA or RNA contrary to acyclovir that has affinity to DNA only. The antiviral activity of these novel compounds showed that compounds 2e and 2f reduced the cytopathogencity of Peste des petits ruminant virus (PPRV) on Vero cell culture by 60 and 50%, respectively.