Spirooxindole-derived morpholine-fused-1,2,3-triazoles: Design, synthesis, cytotoxicity and apoptosis inducing studies.

A series of new spirooxindole-derived morpholine-fused-1,2,3-triazole derivatives has been synthesized from isatin spiro-epoxides. The protocol involves regiospecific isatin-epoxide ring opening with azide nucleophile followed by sequential O-propargylation, and intramolecular 1,3-dipolar cycloaddition reaction. These compounds have been evaluated for their antiproliferative activity against selected human tumor cell lines of lung (A549), breast (MCF-7), cervical (HeLa), and prostate (DU-145). Among the tested compounds, 6i, 6n and 6p showed potent growth inhibition against A549 cell line with IC50 values in the range of 1.87-4.36 μM, which are comparable to reference standards doxorubicin and 5-flourouracil. The compounds 6i and 6p treated A549 cells displayed typical apoptotic morphological features such as cell shrinkage, nuclear condensation, fragmentation, and decreased migration potential. Flow-cytometry analysis revealed that the compounds arrested the cells in G2/M phase of cell cycle. Hoechst and acridine orange/ethidium bromide staining studies also showed that the cell proliferation was inhibited through induction of apoptosis. Moreover, the compounds treatment led to collapse of the mitochondrial membrane potential (DΨm) and increased levels of reactive oxygen species (ROS) were noted in A549 cells.

Senwar KR ，Sharma P ，Reddy TS ，Jeengar MK ，Nayak VL ，Naidu VG ，Kamal A ，Shankaraiah N ... -  《-》

H2O-mediated isatin spiro-epoxide ring opening with NaCN: Synthesis of novel 3-tetrazolylmethyl-3-hydroxy-oxindole hybrids and their anticancer evaluation.

A simple method for isatin spiro-epoxide ring-opening by sodium cyanide in water to obtain a variety of isatin hydroxy nitriles has been developed. Further, these intermediates have been converted into new 3-tetrazolylmethyl-3-hydroxy-oxindole hybrids via azide-nitrile cycloaddition reaction in a sealed tube. These compounds were evaluated for their in vitro anticancer activity on five human cancer cell lines i.e. breast (BT549 and MDA MB-231), prostate (PC-3 and DU-145) and ovarian (PA-1). The compounds 6d and 6r showed potent anticancer activity against DU-145 cell line with IC50 values in the range of 7.01 ± 0.91 and 4.26 ± 0.09 μM respectively. The compounds 6d, 6g, 6q and 6r were also tested on human normal prostate epithelial (RWPE-1) cells and found to be safer with lesser cytotoxicity. The morphology and long term clonogenic survival of DU-145 cells were severely affected by compound 6r. Cell cycle analysis revealed that the compounds arrest the cells in G2/M phase. Acridine orange/ethidium bromide (AO/EB) staining, DAPI staining, annexin-V binding assay and DNA fragmentation analysis showed that cell proliferation was inhibited through induction of apoptosis. Moreover, one of the compounds 6r treatment led to collapse of the mitochondrial membrane potential (DΨm) and increased levels of reactive oxygen species (ROS) in DU-145 cells.

Sharma P ，Senwar KR ，Jeengar MK ，Reddy TS ，Naidu VG ，Kamal A ，Shankaraiah N ... -  《-》

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.

Nagarsenkar A ，Guntuku L ，Guggilapu SD ，K DB ，Gannoju S ，Naidu VGM ，Bathini NB ... -  《-》

Design, synthesis and biological evaluation of 1,3-diphenyl-1H-pyrazole derivatives containing benzimidazole skeleton as potential anticancer and apoptosis inducing agents.

A series of forty different pyrazole containing benzimidazole hybrids (6-45) have been designed, synthesized and evaluated for their potential anti-proliferative activity against three human tumor cell lines - lung (A549), breast (MCF-7), and cervical (HeLa). Some of the compounds, specifically 9, 17, and 28, showed potent growth inhibition against all the cell lines tested, with IC50 values in the range of 0.83-1.81 μM. Breast cancer cells were used for further detailed studies to understand the mechanism of cell growth inhibition and apoptosis inducing effect of compounds. The morphology, cell migration and long term clonogenic survival of MCF-7 breast cancer cells were severely affected by treatment with these compounds. Flow-cytometry revealed the compounds arrested MCF-7 cells in the G1 phase of the cell cycle via down regulation of cyclin D2 and CDK2. Fluorescent staining and DNA fragmentation studies showed that cell proliferation was inhibited by induction of apoptosis. Moreover, the compounds led to collapse of mitochondrial membrane potential (DΨm) and increased levels of reactive oxygen species (ROS) were noted. The ease of synthesis and the remarkable biological activities make these compounds promising new frameworks for the development of cancer therapeutics.

Reddy TS ，Kulhari H ，Reddy VG ，Bansal V ，Kamal A ，Shukla R ... -  《-》

Synthesis and biological evaluation of 1,2,3-triazole linked aminocombretastatin conjugates as mitochondrial mediated apoptosis inducers.

A series of 1,2,3-triazole linked aminocombretastatin conjugates were synthesized and evaluated for cytotoxicity, inhibition of tubulin polymerization and apoptosis inducing ability. Most of the conjugates exhibited significant anticancer activity against some representative human cancer cell lines and two of the conjugates 6d and 7c displayed potent cytotoxicity with IC50 values of 53 nM and 44 nM against A549 human lung cancer respectively, and were comparable to combretastatin A-4 (CA-4). SAR studies revealed that 1-benzyl substituted triazole moiety with an amide linkage at 3-position of B-ring of the combretastatin subunit are more active compared to 2-position. G2/M cell cycle arrest was induced by these conjugates 6d and 7c and the tubulin polymerization assay (IC50 of 1.16 μM and 0.95 μM for 6d and 7c, respectively) as well as immunofluorescence analysis showed that these conjugates effectively inhibit microtubule assembly at both molecular and cellular levels in A549 cells. Colchicine competitive binding assay suggested that these conjugates bind at the colchicine binding site of tubulin as also observed from the docking studies. Further, mitochondrial membrane potential, ROS generation, caspase-3 activation assay, Hoechst staining and DNA fragmentation analysis revealed that these conjugates induce cell death by apoptosis.

Kamal A ，Shaik B ，Nayak VL ，Nagaraju B ，Kapure JS ，Shaheer Malik M ，Shaik TB ，Prasad B ... -  《-》