Experimental investigation and molecular simulations of quinone related compounds as COX/LOX inhibitors.

Quinone-containing compounds have risen as promising anti-inflammatory targets; however, very little research has been directed to investigate their potentials. Accordingly, the current study aimed to design and synthesize group of quinones bearing different substituents to investigate the effect of these functionalities on the anti-inflammatory activities of this important scaffold. The choice of these substituents was carefully done, varying from a directly attached heterocyclic ring to different aromatic moieties linked through a nitrogen spacer. Both in vitro and in vivo anti-inflammatory activities of the synthesized compounds were assessed relative to the positive standards: celecoxib and indomethacin. The in vitro enzymatic and transcription inhibitory actions of all the synthesized compounds were tested against cyclooxygenase-2 (COX-2), cyclooxygenase-1 (COX-1), and 5-lipoxygenase (LOX) and the in vivo gene expression of Interleukin-1, interleukin 10, and Tumor Necrosis Factor-α (TNF-α) were determined. The IC50 against COX-1 and COX-2 enzymes obtained by the immunoassay test revealed promising activities of sixteen compounds with selectivity indices higher than 100-fold COX-2 selectivity. Out of those, four compounds revealed selectivity indices comparable to celecoxib as a reference drug. Furthermore, all the tested compounds inhibited LOX with an IC50 in the range of 1.59-3.11 µM superior to that of the reference drug used; zileuton (IC50 = 3.50 µM). Consequently, these results highlight the promising LOX inhibitory activity of the tested compounds. The obtained in vivo paw edema results showed high inhibitory percentage for the compounds 9a, 9b, and 11a with the significant lower TNF-α relative mRNA expression for compounds 5a, 5d, 9a, 9b, 12d, and 12e. Finally, in silico docking of the most active compounds (5b, 5d, 9a, 9b) against COX2 enzymes presented an acceptable justification of the obtained in vitro inhibitory activities. As a conclusion, Compounds 5b, 5d, 9a, 9b, and 11b showed promising results and thus deserves further investigation.

Discovery of new thymol-3,4-disubstituted thiazole hybrids as dual COX-2/5-LOX inhibitors with in vivo proof.

New thymol-3,4-disubstitutedthiazole hybrids were synthesised as dual COX-2/5-LOX inhibitors. Compounds 6b, 6d, 6e, and 6f displayed in vitro inhibitory activity against COX-2 (IC50= 0.037, 0.042, 0.046, and 0.039 µM) nearly equal to celecoxib (IC50= 0.045 µM). 6b, 6d, and 6f showed SI (379, 341, and 374, respectively) higher than that of celecoxib (327). 6a-l elicited in vitro 5-LOX inhibitory activity higher than quercetin. 6a-f, 6i-l, 7a, and 7c possessed in vivo inhibition of formalin induced paw edoema higher than celecoxib. 6a, 6b, 6f, 6h-l, and 7b showed gastrointestinal safety profile as celecoxib and diclofenac sodium in the population of fasted rats. Induced fit docking and molecular dynamics simulation predicted good fitting of 6b and 6f without changing the packing and globularity of the apo protein. In conclusion, 6b and 6f achieved the target goal as multitarget inhibitors of inflammation.

Imparting aromaticity to 2-pyridone derivatives by O-alkylation resulted in new competitive and non-competitive PIM-1 kinase inhibitors with caspase-activated apoptosis.

New aromatic O-alkyl pyridine derivatives were designed and synthesised as Proviral Integration Moloney (PIM)-1 kinase inhibitors. 4c and 4f showed potent in vitro anticancer activity against NFS-60, HepG-2, PC-3, and Caco-2 cell lines and low toxicity against normal human lung fibroblast Wi-38 cell line. Moreover, 4c and 4f induced apoptosis in the four tested cancer cell lines with high percentage. In addition, 4c and 4f significantly induced caspase 3/7 activation in HepG-2 cell line. Furthermore, 4c and 4f showed potent PIM-1 kinase inhibitory activity with IC50 = 0.110, 0.095 µM, respectively. Kinetic studies indicated that 4c and 4f were both competitive and non-competitive inhibitors for PIM-1 kinase enzyme. In addition, in silico prediction of physiochemical properties, pharmacokinetic profile, ligand efficiency, ligand lipophilic efficiency, and induced fit docking studies were consistent with the biological and kinetic studies, and predicted that 4c and 4f could act as PIM-1 kinase competitive non-adenosine triphosphate (ATP) mimetics with drug like properties.

Discovery of new pyridine-quinoline hybrids as competitive and non-competitive PIM-1 kinase inhibitors with apoptosis induction and caspase 3/7 activation capabilities.

New quinoline-pyridine hybrids were designed and synthesised as PIM-1/2 kinase inhibitors. Compounds 5b, 5c, 6e, 13a, 13c, and 14a showed in-vitro low cytotoxicity against normal human lung fibroblast Wi-38 cell line and potent in-vitro anticancer activity against myeloid leukaemia (NFS-60), liver (HepG-2), prostate (PC-3), and colon (Caco-2) cancer cell lines. In addition, 6e, 13a, and 13c significantly induced apoptosis with percentage more than 66%. Moreover, 6e, 13a, and 13c significantly induced caspase 3/7 activation in HepG-2 cell line. Furthermore, 5c, 6e, and 14a showed potent in-vitro PIM-1 kinase inhibitory activity. While, 5b showed potent in-vitro PIM-2 kinase inhibitory activity. Kinetic studies using Lineweaver-Burk double-reciprocal plot indicated that 5b, 5c, 6e, and 14a behaved as competitive inhibitors while 13a behaved as both competitive and non-competitive inhibitor of PIM-1 kinase enzyme. Molecular docking studies indicated that, in-silico affinity came in coherence with the observed in-vitro inhibitory activities against PIM-1/2 kinases.

Towards safer anti-inflammatory therapy: synthesis of new thymol-pyrazole hybrids as dual COX-2/5-LOX inhibitors.

New thymol - 1,5-disubstitutedpyrazole hybrids were synthesised as dual COX-2/5-LOX inhibitors. Compounds 8b, 8g, 8c, and 4a displayed in vitro inhibitory activity against COX-2 (IC50 = 0.043, 0.045, 0.063, and 0.068 µM) nearly equal to celecoxib (IC50 = 0.045 µM) with high SI (316, 268, 204, and 151, respectively) comparable to celecoxib (327). All target compounds, 4a-c and 8a-i, showed in vitro 5-LOX inhibitory activity higher than reference quercetin. Besides, they possessed in vivo inhibition of formalin-induced paw oedema higher than celecoxib. In addition, compounds 4a, 4b, 8b, and 8g showed superior gastrointestinal safety profile (no ulceration) as celecoxib and diclofenac sodium in the population of fasted rats. In conclusion, compounds 4a, 8b, and 8g achieved the target goal. They elicited in vitro dual inhibition of COX-2/5-LOX higher than celecoxib and quercetin, in vivo potent anti-inflammatory activity higher than celecoxib and in vivo superior gastrointestinal safety profile (no ulceration) as celecoxib.

Discovery of small molecule acting as multitarget inhibitor of colorectal cancer by simultaneous blocking of the key COX-2, 5-LOX and PIM-1 kinase enzymes.

Colorectal cancer (CRC) is the second cause of cancer death worldwide. Inhibitors of COX-2, 5-LOX and PIM-1 kinase were very effective in the treatment and prevention of CRC in mouse models in vivo. Furthermore, thymol was confirmed to inhibit CRC cell proliferation in cancer cell lines and inhibitory activity against COX-2 and 5-LOX. On the other hand, 4-thiazolidinone pharmacophore was incorporated in the structures of various reported COX-2, 5-LOX and PIM kinase inhibitors. Consequently, the aim of the present investigation was to combat CRC by synthesis and biological evaluation of new thymol - 4-thiazolidinone hybrids as multitarget anticancer agents that could inhibit the key COX-2, 5-LOX and PIM-1 kinase enzymes simultaneously. Compounds 5a-d and 5g displayed inhibitory activity against COX-2 nearly equal to Celecoxib with high selectivity index (SI). Moreover, compounds 5b-e showed 5-LOX inhibitory activity nearly equal to the reference Quercetin while compounds 5a, 5f and 5g elicited inhibitory activity slightly lower than Quercetin. Furthermore, in vivo formalin-induced paw edema test revealed that, compounds 5a, 5c, 5f and 5g showed higher % inhibition than Celecoxib and compounds 5a, 5f and 5g showed higher % inhibition than Diclofenac sodium. In addition, compounds 5a-c, 5e-g showed in vivo superior gastrointestinal safety profile as Celecoxib in fasted rats. Besides, compounds 5d, 5e and 5g exhibited the highest activity against human CRC cell lines (Caco-2 and HCT-116) at doses less than their EC100 on normal human cells. Furthermore, compounds 5e and 5g induced apoptosis-dependent death by above 50% in the treated CRC cell lines. Moreover, compounds 5e and 5g induced caspase activation by >50% in human CRC. Also, compounds 5d, 5e and 5g showed in vitro inhibitory activity against both PIM-1\2 kinases comparable to the reference Staurosporine. In silico docking studies were concordant with the biological results. In conclusion, compound 5g, of simple chemical structure, achieved the target goal of inhibiting three targets leading to inhibition of human CRC cell proliferation. It inhibited the target key enzymes COX-2, 5-LOX and PIM-1\2 kinase in vitro. Besides, it revealed in vitro inhibition of cell proliferation in cancer cell lines via activation of caspase 3\7 dependent-apoptosis in human CRC cell lines. In addition, it elicited in vivo anti-inflammatory activity in formalin-induced paw edema test and in vivo oral safety in gastric ulcerogenic activity test.

Transforming iodoquinol into broad spectrum anti-tumor leads: Repurposing to modulate redox homeostasis.

We managed to repurpose the old drug iodoquinol to a series of novel anticancer 7-iodo-quinoline-5,8-diones. Twelve compounds were identified as inhibitors of moderate to high potency on an inhouse MCF-7 cell line, of which 2 compounds (5 and 6) were capable of reducing NAD level in MCF-7 cells in concentrations equivalent to half of their IC50s, potentially due to NAD(P)H quinone oxidoreductase (NQO1) inhibition. The same 2 compounds (5 and 6) were capable of reducing p53 expression and increasing reactive oxygen species levels, which further supports the NQO-1 inhibitory activity. Furthermore, 4 compounds (compounds 5-7 and 10) were qualified by the Development Therapeutic Program (DTP) division of the National Cancer Institute (NCI) for full panel five-dose in vitro assay to determine their GI50 on the 60 cell lines. All five compounds showed broad spectrum sub-micromolar to single digit micromolar GI50 against a wide range of cell lines. Cell cycle analysis and dual staining assays with annexin V-FITC/propidium iodide on MCF-7 cells confirmed the capability of the most active compound (compound 5) to induce cell cycle arrest at Pre-G1 and G2/M phases as well as apoptosis. Both cell cycle arrest and apoptosis were affirmed at the molecular level by the ability of compound 5 to enhance the expression levels of caspase-3 and Bax together with suppressing that of CDK1 and Bcl-2. Additionally, an anti-angiogenic effect was evident with compound 5 as supported by the decreased expression of VEGF. Interesting binding modes within NQO-1 active site had been identified and confirmed by both molecular docking and dymanic experiments.

Synthesis, antibacterial evaluation, and DNA gyrase inhibition profile of some new quinoline hybrids.

Antibiotic-resistant bacteria continue to play an important role in human health and disease. Inventive strategies are necessary to develop new therapeutic leads to challenge drug-resistance problems. From this perception, new quinoline hybrids bearing bioactive pharmacophores were synthesized. The newly synthesized compounds were evaluated for their in vitro antibacterial activity against nine bacterial pathogenic strains. The results revealed that most compounds exhibited good antibacterial activities. Seven compounds (2b, 3b, 4, 6, 8b, and 9c,d) displayed enhanced activity against methicillin-resistant Staphylococcus aureus compared to ampicillin. These compounds were subjected to an in vitro S. aureus DNA gyrase ATPase inhibition study, which revealed that compounds 8b, 9c, and 9d showed the highest inhibitory activity with IC50 values of 1.89, 2.73, and 2.14 µM, respectively, comparable to novobiocin (IC50 , 1.636 µM). Compounds 2a-c, 3a, 7c, 9c,d, and 10a,b revealed half the potency of levofloxacin in inhibiting the growth of Pseudomonas aeruginosa. As an attempt to rationalize the observed antibacterial activity for the most active compounds 8b, 9c, and 9d, molecular docking in the ATP binding site of S. aureus gyrase B was performed using Glide. Such compounds could be considered as promising scaffolds for the development of new potent antibacterial agents.

New pyrimidines and triazolopyrimidines as antiproliferative and antioxidants with cyclooxygenase-1/2 inhibitory potential.

Aim: Cyclooxygenase-2 (COX-2) inhibition and scavenging-free radicals are important targets in cancer treatment. Materials & methods: Sulfanylpyrimidines and triazolopyrimidines were synthesized and evaluated as anticancer and antioxidant COX-1/2 inhibitors. Results: Compound 7 showed the same growth inhibitory activity as 5-fluorouracil against MCF-7. Compound 6f displayed broad-spectrum anticancer activity against the four tested cancer cell lines. Compounds 5b, 6a, 6c, 6d and 8 were found to be more active antioxidants than trolox. Compounds 6a, 6c, 6f and 8 revealed high COX-2 inhibitory activity and selectivity, which was confirmed by docking studies. Conclusion: Compound 6f could be considered as promising anticancer and antioxidant structural lead with COX-2 inhibition that deserve further derivatization and investigation.

Design, synthesis and docking study of pyridine and thieno[2,3-b] pyridine derivatives as anticancer PIM-1 kinase inhibitors.

A series of pyridine and thieno[2,3-b]pyridine derivatives have been designed and synthesized as anticancer PIM-1 kinase inhibitors. Thirty-seven compounds were selected by NCI to be tested initially at a single dose (10 µM) in the full NCI 60 cell line panel. Compound 5b showed potent anticancer activity and was tested twice in the five-dose assay which confirmed its potent antitumor activity (GI50 values 0.302-3.57 µM) against all tested tumor cell lines except six cell lines where they showed moderate sensitivity. This compound was sent to NCI biological evaluation committee and still under consideration for further testing. In addition, the most active anticancer compounds in each series, 5b, 8d, 10c, 13h, and 15e, were evaluated for their PIM-1 kinase inhibitory activity. Compound 8d was the most potent one with IC50 = 0.019 µM followed by 5b, 15e, 10c and 13h with IC50 values 0.044, 0.083, 0.128 and 0.479 µM respectively. Moreover, docking study of the most active compounds in PIM-1 kinase active site was consistent with the in vitro activity.

Novel click modifiable thioquinazolinones as anti-inflammatory agents: Design, synthesis, biological evaluation and docking study.

Click chemistry was used to synthesize a new series of thioquinazolinone molecules equipped with propargyl moiety,1,2,3-triazolyl and isoxazolyl rings. Our design was based on merging pharmacophores previously reported to exhibit COX-2 inhibitory activities to a thioquinazolinone-privileged scaffold. The synthesized compounds were subjected to in vitro cyclooxygenase COX-1/COX-2 and 15-LOX inhibition assays. Compounds 2c, 3b, 3h, 3j, and 3k showed COX-2 inhibition with IC50 (µM) 0.18, 0.19, 0.11, 0.16 and 0.17 respectively. These values were compared to celecoxib (IC50 0.05 µM), diclofenac (IC50 0.8 µM) and indomethacin (IC50 0.49 µM) reference drugs. They also showed 15-LOX inhibition with IC50 (µM) 6.21, 4.33, 7.62, 5.21 and 3.98 respectively. These values were compared with Zileuton (IC50 2.41 µM) and Meclofenamate sodium (IC50 5.64 µM) as positive controls. These compounds were further challenged by PMA-induced THP-1 differentiation assay where compounds 2c and 3j inhibited monocyte to macrophage differentiation efficiently with IC50 values of 4.78 µM and 5.63 µM, respectively, compared to that of diclofenac sodium (4.86 µM). On the other hand, 3h demonstrated a significantly increased potency compared to diclofenac in this assay (IC50 = 0.13 µM). The same compounds exhibited significant in vivo anti-inflammatory effect as indicated by the formalin-induced rat-paw edema test. Docking experiments of compounds 2c, 3b, 3h, 3j, and 3k into COX-2 binding pocket have been conducted, where strong binding interactions have been identified and effective overall docking scores have been recorded. Their drug-likeness has been assessed using Molinspiration, Molsoft and Pre-ADMET software products.

New benzothiophene derivatives as dual COX-1/2 and 5-LOX inhibitors: synthesis, biological evaluation and docking study.

AIM: Simultaneous inhibition of 5-LOX/COX may enhance anti-inflammatory effects and reduce side effects. Hence, synthesis of novel dual inhibitors of 5-LOX/COX is an important strategy for treatment of inflammation. Results/methodology: The target compounds were designed to hybridize benzothiophene scaffold or its bioisostere benzofuran with various anti-inflammatory pharmacophore hetercycles through different atoms spacers. Compounds 4a, 4c, 4d, 5b, 7a, showed significant in vitro LOX inhibitory activity higher than that of meclofenamate sodium. Compounds 4b, 4e, 4f, 5a exhibited significant in vitro COX-2 inhibition higher than celecoxib and in vitro LOX inhibitory activity twice that of reference. These compounds elicited significant in vivo anti-inflammatory activities higher than celecoxib in formalin-induced paw edema test. Compound 4e exhibited gastrointestinal safety profile as celecoxib. The results were also consistent with the docking studies. CONCLUSION: Compound 4e could be considered as structural lead for the development of a new class of anti-inflammatory agents with better safety profile.

New hybrid molecules combining benzothiophene or benzofuran with rhodanine as dual COX-1/2 and 5-LOX inhibitors: Synthesis, biological evaluation and docking study.

New molecular hybrids combining benzothiophene or its bioisostere benzofuran with rhodanine were synthesized as potential dual COX-2/5-LOX inhibitors. The benzothiophene or benzofuran scaffold was linked at position -2 with rhodanine which was further linked to various anti-inflammatory pharmacophores so as to investigate the effect of such molecular variation on the anti-inflammatory activity. The target compounds were evaluated for their in vitro COX/LOX inhibitory activity. The results revealed that, compound 5h exhibited significant COX-2 inhibition higher than celecoxib. Furthermore, compounds 5a, 5f and 5i showed COX-2 inhibitory activity comparable to celecoxib. Compound 5h showed selectivity index SI=5.1 which was near to that of celecoxib (SI=6.7). Compound 5h displayed LOX inhibitory activity twice than that of meclofenamate sodium. Moreover, compounds 5a, 5e and 5f showed significant LOX inhibitory activity higher than that of meclofenamate sodium. Compound 5h was screened for its in vivo anti-inflammatory activity using formalin-induced paw edema and gastric ulcerogenic activity tests. The results revealed that, it showed in vivo decrease in formalin-induced paw edema volume higher than celecoxib. It also displayed gastrointestinal safety profile as celecoxib. The biological results were also consistent with the docking studies at the active sites of the target enzymes COX-2 and 5-LOX. Also, compound 5h showed physicochemical, ADMET, and drug-like properties within those considered adequate for a drug candidate.

Synthesis of novel benzofuran and related benzimidazole derivatives for evaluation of in vitro anti-HIV-1, anticancer and antimicrobial activities.

Previously, we synthesized and evaluated several benzofuran derivatives containing heterocyclic ring substituents linked to the benzofuran nucleus at C-2 by a two- to four-atom spacer as potential anti-HIV-1, anticancer and antimicrobial agents. Among these derivatives, NSC 725612 and NSC 725716 exhibited interesting anti-HIV-1 activity. To further investigate the structure-activity relationship, we synthesized several new benzofuran derivatives derived from 2-acetylbenzofuran (2, 3a-c) and 2-bromoacetylbenzofuran (6; 7a,b; 8a,b). The compounds were designed to comprise the heterocyclic substituents directly linked to the benzofuran nucleus at C-2. Moreover, various related benzimidazoles derived from 2-acetylbenzimidazole and from 2-cyanomethylbenzimidazole (12a,b; 13a,b; 15; 16a,b) were also prepared as isosteres. The synthesized compounds were preliminarily evaluated for their in vitro anti-HIV-1, anticancer and antimicrobial activity. Compounds 2, 3a, 3b, and 12b showed weak anti-HIV-1 activity. Compound 6 exhibited mild activity against S. aureus, while compound 15 had mild activity towards S. aureus and C. albicans. However, no significant anticancer activity was observed with any of the tested compounds. From these results, we conclude that the presence of the spacer between the heterocyclic substituent and the benzofuran nucleus may be essential for the biological activity.