Synthesis of thiazole linked indolyl-3-glyoxylamide derivatives as tubulin polymerization inhibitors.

A series of thiazole linked indolyl-3-glyoxylamide derivatives were synthesized and evaluated for their in vitro cytotoxic activity against DU145 (prostate), PC-3 (prostate), A549 (lung) and HCT-15 (colon) cancer cell lines by employing the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay. Among all the synthesized compounds, compound 13d displayed cytotoxicity of IC50 = 93 nM towards DU145 cancer cell line. The most active compound 13d was also tested on RWPE-1 cells and was found to be safe compared to the DU145 cells. The target compounds were also evaluated for their inhibition activity of tubulin polymerization. Further, the treatment of compound 13d on DU145 cells led to the inhibition of cell migration ability. The detailed studies such as acridine orange/ethidium Bromide (AO/EB), DAPI, annexin V-FITC/propidium iodide staining assay suggested that the compound 13d induced apoptosis in DU145 cells. The influence of the cytotoxic compound 13d on the cell cycle distribution was assessed on the DU145 cell line, exhibiting a cell cycle arrest at the G2/M phase. Moreover, the treatment with compound 13d caused collapse of mitochondrial membrane potential and elevated intracellular ROS levels in DU145 cells. The results from molecular modelling studies revealed that these compounds bind at the colchicine binding site of the tubulin. Thus, this new molecular scaffold could be a new lead for the development of anticancer agents that target tubulin.

Synthesis of C5-tethered indolyl-3-glyoxylamide derivatives as tubulin polymerization inhibitors.

A series of C5-tethered Indolyl-3-glyoxylamide derivatives were synthesized and evaluated for their in vitro cytotoxic activity against DU145 (prostate), PC-3 (prostate), A549 (lung) and HCT-15 (colon) cancer cell lines by employing the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay. Among all the synthesized compounds, compound 7f displayed cytotoxicity of IC50 = 140 nM towards DU145 cancer cell line. The treatment of DU145 cells with 7f led to inhibition of cell migration ability. Futher, the detailed studies such as acridine orange/ethidium Bromide (AO/EB), DAPI, annexin V-FITC/propidium iodide staining assay suggested that the compound 7f induced apoptosis in DU145 cells. The influence of the cytotoxic compound 7f on the cell cycle distribution was assessed on the DU145 cell line, exhibiting a cell cycle arrest at the G2/M phase (hallmark of tubulin polymerization) and next inhibited tubulin polymerization with IC50 0.40 µM. Furthermore, the treatment with compound 7f caused collapse of mitochondrial membrane potential and elevated intracellular superoxide ROS levels in DU145 cells. Western blotting was performed to examine the levels of apoptotic proteins (Bcl-2 and Bax); the study confirmed that compound 7f induced apoptosis through apoptosis-related protein expression. Thus, these studies provided a new molecular scaffold for the further development of anticancer agents that target tubulin.

Synthesis and apoptosis inducing studies of triazole linked 3-benzylidene isatin derivatives.

In our venture towards the development of effective cytotoxic agents, a panel of triazole linked 3-benzylidene isatin hybrids were synthesized and characterized by IR, 1H NMR, 13C NMR and Mass spectral analysis. All the newly synthesized target compounds were assessed against DU145 (prostate), PC-3 (prostate), MDA-MB-231 (breast), BT549 (breast), A549 (lung) and HeLa (cervical) human cancer cell lines by employing MTT assay for their cytotoxic potential. Significantly, compound Z-8l was found to be most potent amongst all the tested compounds with an IC50 value of (3.7 ± 0.05 µM) on DU145 cells. The most active compound (Z-8l) was also tested on RWPE-1 (normal prostate) cells and was found to be safe compared to the DU145 cells. The influence of the cytotoxic compound Z-8l on the cell cycle distribution was assessed on the DU145 cell line, exhibiting a cell cycle arrest at the G2/M phase. Additionally, treatment with compound Z-8l caused collapse of mitochondrial membrane potential (DΨm) in DU145 cells. Moreover, acridine orange/ethidium bromide staining, DAPI nuclear staining, DCFDA staining and annexin V binding assay confirmed that compound Z-8l can induce cell apoptosis in DU145 cells. Western blotting was performed to examine the appearance of active forms of cytochrome c, Bax, Bcl2 and PARP (Poly ADP ribose polymerase), indicator proteins of apoptosis in DU145 cells; the study confirmed the triggering of mitochondrial mediated apoptotic pathway upon exposure of compound Z-8l.

Synthesis and biological evaluation of oxindole linked indolyl-pyrimidine derivatives as potential cytotoxic agents.

In our endeavor towards the development of effective cytotoxic agents, a series of oxindole linked indolyl-pyrimidine derivatives were synthesized and characterized by IR, (1)H NMR, (13)C NMR and Mass spectral analysis. All the newly synthesized target compounds were assessed against PA-1 (ovarian), U-87MG (glioblastoma), LnCaP (prostate), and MCF-7 (Breast) cancer cell lines for their cytotoxic potential, with majority of them showing inhibitory activity at low micro-molar concentrations. Significantly, compound 8e was found to be most potent amongst all the tested compounds with an IC50 value of (2.43±0.29µM) on PA-1 cells. The influence of the most active cytotoxic compound 8e on the cell cycle distribution was assessed on the PA-1 cell line, exhibiting a cell cycle arrest at the G2/M phase. Moreover, acridine orange/ethidium bromide staining and annexin V binding assay confirmed that compound 8e can induce cell apoptosis in PA-1 cells. These preliminary results persuade further investigation on the synthesized compounds aiming to the development of potential cytotoxic agents.

Aldehyde-Promoted One-Pot Regiospecific Synthesis of Acrylamides Using an in Situ Generated Molybdenum Tetracarbonyl Amine [Mo(CO)4(amine)2] Complex.

A novel complex system generated in situ from Mo(CO)6 and an amine is described for the regiospecific aminocarbonylation of various terminal alkynes. The Mo(CO)6-amine system played a dual role as complexing agent and as CO donor, thus making this process palladium-free.