Design, Synthesis, Anti-Proliferative Evaluation and Cell Cycle Analysis of Hybrid 2-Quinolones

Synthesis and antitumor potential of new arylidene ursolic acid derivatives via caspase-8 activation

Continuing our studies on NO-donating ursolic acid-benzylidene derivatives as potential antitumor agents, we designed and synthesized a series of new arylidene derivatives containing NO-donating ursolic acid and aromatic heterocyclic units. Compounds 5c and 6c showed a significant broad-spectrum antitumor activity. Compound 5c exhibited nearly three- to nine-fold higher cytotoxicity as compared with the parent drug in A549, MCF-7, HepG-2, HT-29, and HeLa cells, and it was also found to be the most potent apoptosis inducer of MCF-7 cells. More importantly, compound 5c arrested the MCF-7 cell cycle in the G1 phase, which was associated with caspase activation and a decrease of the Bcl-2/Bax ratio. Meanwhile, compound 5c caused changes in morphological features, dissipation of the mitochondrial membrane potential, and accumulation of reactive oxygen species. A docking study revealed that the nitroxyethyl moiety of compound 5c may form hydrogen bonds with caspase-8 amino acid residues (SER256 and HIS255). Together, these data suggest that NO-donating ursolic acid-arylidene derivatives are potent apoptosis inducers in tumor cells.

Fucoidan induces ROS-dependent epigenetic modulation in cervical cancer HeLa cell

Fucoidan is a sulfated polysaccharide obtained from marine algae and known for various pharmacological activities. In this study, we investigated the effect of Fucoidan on cell viability, redox balance, cytoskeletal component F-actin, HDAC inhibition, autophagy, and senescence phenomenon in human cervical cancer HeLa cell line in comparison to positive control suberoylanilide hydroxamic acid by flow cytometry, fluorescence microscopy, and western blotting. Our observations revealed that Fucoidan exposure induces cytotoxicity in HeLa cells via ROS and mitochondrial superoxide generation and loss of ATP. Colorimetrical studies suggested that Fucoidan impairs the function of HDAC expression. Fucoidan treatment also contributes to the change in the granularity of cells, senescence-associated heterochromatin foci formation that leads to senescence in HeLa cells. Moreover, we visualize that Fucoidan exhibits autophagosomes formation with monodansylcadaverine, and flow cytometry analysis by acridine orange further substantiates that Fucoidan triggers autophagy in HeLa cells. Additionally, the changes in the expression of proteins p21, p16, BECN1, and HDAC1 were seen as markers of senescence, autophagy, and HDAC inhibition by FACS and immunoblotting. Molecular docking study validates Fucoidan-HDAC1 association in corroboration with the experimental data. Collectively, these mechanistic studies demonstrated that Fucoidan could be a therapeutic molecule for targeting HDACs in cervical cancer.

Exploring quinolone scaffold: Unravelling the chemistry of anticancer drug design

Globally, cancer is considered as the major leading cause in decreasing the patient health care system of human beings. The growing threat from drug-resistant cancers makes heterocyclic moieties as an urgent need to develop more successful candidates for anti-cancer therapy. In view of outstanding pharmacological activities Quinolone and its derivatives have attracted more attention towards drug designing and biological evaluation in the search of new drug molecules. The inspired researchers attempted efforts in order to discover quinolone based analogs due to its wide range of biological activities. Due to immense pharmacological importance, distinct synthetic methods have been executed to attain new drug entities from quinolones and all the reported molecules have shown constructive anticancer activity. Some of the synthetic protocol like, one pot synthesis, post-Ugi-transformation, catalysed based synthesis, enzyme-based synthesis and nano-catalyst based synthetic procedures are also discussed as recent advancement in production of quinolone derivatives. In this review, recent synthetic approaches in the medicinal chemistry of quinolones and potent quinolone derivatives on the basis of structural activity relationship are outlined. Moreover, their major methods and modifications are discussed.

Synthesis, Cytotoxicity, ADMET and Molecular Docking Studies of Some Quinoline-Pyrimidine Hybrid Compounds: 3-(2-Amino-6-arylpyrimidin-4- yl)-4-hydroxy-1-methylquinolin-2(1H)-ones

AIMS

Synthesis of 3-(2-amino-6-arylpyrimidin-4-yl)-4-hydroxy-1-methylquinolin-2(1H)-ones and estimation their anticancer activities on HepG2 and KB cancer lines.

BACKGROUND

Many derivatives of quinoline-2-on have been consider to synthesize and evaluate their biological properties by organic chemists due to their various biological effects, including antibacterial, antioxidant, anti-inflammatory, anticancer activities. Quinolinepyrimidine hybrid compounds exhibited various biological activities, such as antituberculosis, antibacterial, anticancer, antifungal, etc. The connection of 4-hydroxyquinoline-2-one with 2-amino-pyrimidine could initiate the new activities.

OBJECTIVE

α,β-Unsaturated ketones of 3-acetyl-4-hydroxy-N-methylquinolin-2-one were prepared. Novel 2-amino-6-aryl-4-(4'-hydroxy-Nmethylquinolin- 2'-on-3'-yl)pyrimidines have been synthesized by reaction of these corresponding α,β-unsaturated ketones with guanidine hydrochloride. Human hepatocellular carcinoma HepG2 and squamous cell carcinoma KB cancer lines were used for screening their cytotoxicity.

METHOD

3-Acetyl-4-hydroxy-N-methylquinolin-2-one was prepared from N-methylaniline and diethyl malonate. Reaction of (un)substituted benzaldehydes with this 4-hydroxyquinoline-2-one produced corresponding substituted α ,β-unsaturated ketones in the presence of piperidine as catalyst. 2-Amino-6-aryl-4-(4'-hydroxy-N-methylquinolin-2'-on-3'-yl)pyrimidines have been synthesized from these α,β-unsaturated ketones of 3-acetyl-4-hydroxy-N-methylquinolin-2-one by reaction of corresponding α ,β-unsaturated ketones with guanidine hydrochloride. All obtained pyrimidines were screened for anticancer activity using MTT bio-assay method.

RESULT

Seven substituted (E)-4-hydroxy-3-(3-(aryl)acryloyl)-1-methylquinolin-2(1H)-ones were prepared and converted to corresponding substituted 2-amino-6-aryl-4-(4'-hydroxy-N-methylquinolin-2'-on-3'-yl)pyrimidines with yields of 58-74%. All the synthesized pyrimidines were screened for their in vitro anticancer activity against human hepatocellular carcinoma HepG2 and squamous cell carcinoma KB cancer lines. Compounds 6b and 6e had the best activity in the series, with IC50 values equal to 1.32 and 1.33 μM, respectively. ADMET properties showed that compounds 6b, 6e, and 6f possessed the drug-likeness behavior. Cross-docking results indicated that residues GLN778(A), DT8(C), DT9(D), DA12(F), and DG13(F) in the binding pocket as potential ligand binding hot-spot residues for compounds 6b, 6e, and 6f.

CONCLUSION

New substituted 2-amino-6-aryl-4-(4'-hydroxy-N-methylquinolin-2'-on-3'-yl)pyrimidines were obtained and displayed significant inhibition against human hepatocellular carcinoma HepG2 and squamous cell carcinoma KB cancer lines.

Synthesis of some novel 2-(3-cyano -6-(thiophen- 2-yl)-4,4'- bipyridin-2- yloxy)acetohydrazide derivatives: assessment of their cytotoxic activity

A new series of pyrazole, bipyridine, N-amide derivatives and Schiff bases was synthesized using compound 2-(3-cyano-6- (thiophen-2-yl)-4,4'- bipyridin-2-yloxy) acetohydrazide (3) as a starting material. The compounds structures were confirmed depending on the spectroscopic methods and elemental analysis. Also, the compounds were evaluated as anticancer agents by the compounds screened towards adenocarcinoma breast cancer cell line (MCF-7). The compounds showed a promising cytotoxic effect against human breast cancer cells. Compound 7c showed the most effective activity compared to other compounds with (IC₅₀ = 0.6 ± 0.01 μg mL^-1) in comparison with the reference drug doxorubicin (IC₅₀ = 1.6 ± 0.02 μg mL^-1). While compound 3 is closely active with doxorubicin. Also compounds 2, 4, 6, 7a, 7b and 7d showed noticeable cytotoxic effect. Early and late apoptotic cells were detected using Acridine orange/Ethidium bromide staining technique. The results of biologically screening of the tested compounds give an idea about the importance in the compounds acting against breast cancer and may lead to the discovery of a potent anticancer agent.