Xanthone Conjugated Amino Acids as Potential Anticancer and DNA Binding Agents: Molecular Docking, Cytotoxicity and SAR Studies

BACKGROUND

Amino acids conjugated with heterocyclic molecules are well known for their effective bioactive properties. In search of effective anticancer agents, a series of xanthone linked amino acids 2-23 were synthesized and tested for in vitro anticancer activity.

METHODS

In vitro anticancer activity of the synthesized xanthone linked amino acids 2-23 are tested against three different cancer cell lines MCF-7, MDA-MB-435 and A549 by MTT assay and validated by DNA binding and molecular docking approaches. Doxorubicin and ethidium bromide used as standard and positive control respectively.

RESULTS

Compounds 7, 8 and 9 exhibited potent anticancer activity against tested cancer cell lines and DNA binding study using methyl green. In the molecular docking study, binding interactions of the most active compounds 7, 8 and 9 were confirmed to molecular surface of DNA.

CONCLUSION

Structure-Activity Relationship (SAR) showed that the aromatic and hydrophobic amino acids (phenylalanine, tyrosine, and tryptophan) favoured the DNA binding studies and anticancer activity whereas, aliphatic amino acids showed least anticancer activity.

A Benzothiazole Derivative (5g) Induces DNA Damage And Potent G2/M Arrest In Cancer Cells

Chemically synthesized small molecules play important role in anticancer therapy. Several chemical compounds have been reported to damage the DNA, either directly or indirectly slowing down the cancer cell progression by causing a cell cycle arrest. Direct or indirect reactive oxygen species formation causes DNA damage leading to cell cycle arrest and subsequent cell death. Therefore, identification of chemically synthesized compounds with anticancer potential is important. Here we investigate the effect of benzothiazole derivative (5g) for its ability to inhibit cell proliferation in different cancer models. Interestingly, 5g interfered with cell proliferation in both, cell lines and tumor cells leading to significant G2/M arrest. 5g treatment resulted in elevated levels of ROS and subsequently, DNA double-strand breaks (DSBs) explaining observed G2/M arrest. Consistently, we observed deregulation of many cell cycle associated proteins such as CDK1, BCL2 and their phosphorylated form, CyclinB1, CDC25c etc. Besides, 5g treatment led to decreased levels of mitochondrial membrane potential and activation of apoptosis. Interestingly, 5g administration inhibited tumor growth in mice without significant side effects. Thus, our study identifies 5g as a potent biochemical inhibitor to induce G2/M phase arrest of the cell cycle, and demonstrates its anticancer properties both ex vivo and in vivo.

Synthesis and antileukemic activity of novel 2-(4-(2,4-dimethoxybenzoyl)phenoxy)-1-(4-(3-(piperidin-4-yl)propyl)piperidin-1-yl)ethanone derivatives

A series of novel 2-(4-(2,4-dimethoxybenzoyl)phenoxy)-1-(4-(3-(piperidin-4-yl)propyl) piperidin-1-yl)ethanone derivatives 9(a-e) and 10(a-g) were synthesized and characterized by (1) H NMR, IR, mass spectral, and elemental analysis. These novel compounds were evaluated for their antileukemic activity against two human leukemic cell lines (K562 and CEM) by using the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazoliumbromide assay. Some of the tested compounds showed good antiproliferative activity with IC(50) values ranging from 1.6 to 8.0 μm. Compound 9c, 9e, and 10f with an electron-withdrawing halogen substituent at the para position on the phenyl ring showed excellent in vitro potency against tested human leukemia cells (K562 and CEM).

Synthesis and antileukemic activity of novel 4-(3-(piperidin-4-yl) propyl)piperidine derivatives

To explore the anticancer effect associated with the piperidine framework, several (substituted phenyl) {4-[3-(piperidin-4-yl)propyl]piperidin-1-yl} methanone derivatives 3(a-i) were synthesized. Variation in the functional group at N-terminal of the piperidine led to a set of compounds bearing amide moiety. Their chemical structures were confirmed by (1) H NMR, IR and mass spectra analysis. Among these, compounds 3a, 3d and 3e were endowed with antiproliferative activity. The most active compound among this series was 3a with nitro and fluoro substitution on the phenyl ring of aryl carboxamide moiety, which inhibited the growth of human leukemia cells (K562 and Reh) at low concentration. Comparison with other derivative (3h) results shown by LDH assay, cell cycle analysis and DNA fragmentation suggested that 3a is more potent to induce apoptosis.

Synthesis, characterization and in-vitro antiproliferative effects of novel 5-amino pyrazole derivatives against breast cancer cell lines

In search of synthetic chemotherapeutic substances capable of inhibiting, retarding, or reversing the process of multistage carcinogenesis, we synthesised a series of novel 1-(4-methoxybenzyl)-3-cyclopropyl-1H-pyrazol-5-amine derivatives 9(a-h) by a nucleophilic substitution reaction and characterized by (1)H and (13)C nuclear magnetic resonance (NMR), liquid chromatography mass spectrometry (LC/MS), Fourier-transform infrared (FTIR), and elemental analysis. These novel compounds were evaluated for their efficacy in inhibiting VERO normal and MCF-7 breast cancer cells proliferation by trypan blue exclusion assay, MTT assay, [(3)H] thymidine incorporation assay and DNA fragmentation analysis. Among the series, some compounds exhibited interesting growth inhibitory effects against cell lines. From the Structure-Activity Relationship studies, it has been revealed that, both novel patented compounds and therapeutic protocols of N-terminal pyrazole ring structures play key role in the antiproliferative activity.

Effect of novel N-aryl sulfonamide substituted 3-morpholino arecoline derivatives as muscarinic receptor 1 agonists in Alzheimer's dementia models

A series of novel, potent, and selective muscarinic receptor 1 agonists (M1 receptor agonists) that employ a key N-substituted morpholine Arecoline moiety has been synthesized as part of research effort for the therapy of Alzheimer's diseases. The ester group of arecoline (which is reported as muscarinic agonist) has been replaced by N-substituted morpholine ring. The structure-activity relationship reveals that the electron donating 4-substituted sulfonyl derivatives (9a, 9b, 9c, and 9e) on the nitrogen atom of the morpholine ring increases the affinity of M1 receptor binding 50- to 80-fold greater than the corresponding arecoline. Other derivatives also showed considerable M1 receptor binding affinity.