Novel Coumarin-Containing Aminophosphonatesas Antitumor Agent: Synthesis, Cytotoxicity, DNA-Binding and Apoptosis Evaluation.

A series of novel coumarin-containing α-aminophosphonates were synthesized and evaluated for their antitumor activities against Human colorectal (HCT-116), human nasopharyngeal carcinoma (human KB) and human lung adenocarcinoma (MGC-803) cell lines in vitro. Compared with 7-hydroxy-4-methylcoumarin (4-MU), most of the derivatives showed an improved antitumor activity. Compound 8j (diethyl 1-(3-(4-methyl-2-oxo-2H-chromen-7-yloxy) propanamido)-1-phenylethyl-Phosphonate), with IC50 value of 8.68 µM against HCT-116 cell lines, was about 12 fold than that of unsubstituted parent compound. The mechanism investigation proved that 8c, 8d, 8f and 8j were achieved through the induction of cell apoptosis by G1 cell-cycle arrest. In addition, the further mechanisms of compound 8j-induced apoptosis in HCT-116 cells demonstrated that compound 8j induced the activations of caspase-9 and caspase-3 for causing cell apoptosis, and altered anti- and pro-apoptotic proteins. DNA-binding experiments suggested that some derivatives bind to DNA through intercalation. The results seem to imply the presence of an important synergistic effect between coumarin and aminophosphonate, which could contribute to the strong chelating properties of aminophosphonate moiety.

Synthesis and antitumor activities of novel rhein α-aminophosphonates conjugates.

Several rhein α-aminophosphonates conjugates (5a-5q) were synthesized and evaluated for in vitro cytotoxicity against HepG-2, CNE, Spca-2, Hela and Hct-116 cell lines. Some compounds showed relatively high cytotoxicity. Especially, compound 5i exhibited the strongest cytotoxicity against Hct-116 cells (IC50 was 5.32 µM). All the synthesized compounds exhibited low cytotoxicity against HUVEC cells. The mechanism of compound 5i was preliminarily investigated by Hoechst 33258 staining, JC-1 mitochondrial membrane potential staining and flow cytometry, which indicated that the compound 5i induced apoptosis in Hct-116 cancer cells. Cell cycle analysis showed that these compound 5i mainly arrested Hct-116 cells in G1 stage. The effects of 5i on the activation of caspases expression indicated that 5i might induce apoptosis via the membrane death receptor pathways. In addition, the binding properties of a model analog 5i to DNA were investigated by methods (UV-vis, fluorescence, CD spectroscopy and FRET-melting) in compare with that of rhein. Results indicated that 5i showed moderate ability to interact ct-DNA.

Synthesis and antitumor activity evaluation of maleopimaric acid N-aryl imide atropisomers.

Maleopimaric acid N-aryl imides (2) and methyl maleopimaric acid N-aryl imides (3) were designed and synthesized. Their atropisomers (A and B) were separated into their enantiomeric pure forms and the anti-proliferative activity was tested against NCI, A549, Hep G-2, MGC-803 and Hct-116 cell lines, respectively. A significant difference in the level of cytotoxicity was observed between R and S conformers. Atropisomers A with an R configuration exhibited significant toxicity (the IC50 values ranging from 7.51 to 32.1 µM). Further experiments proved that antitumor activity of 2A was achieved through the induction of cell apoptosis by G1 cell-cycle arrest.

Synthesis, cytotoxicity, DNA binding and apoptosis of rhein-phosphonate derivatives as antitumor agents.

Several rhein-phosphonate derivatives (5a-c) were synthesized and evaluated for in vitro cytotoxicity against HepG-2, CNE, Spca-2, Hela and Hct-116 cell lines. Some compounds showed relatively high cytotoxicity. Especially compounds 5b exhibited the strongest cytotoxicity against HepG-2 and Spca-2 cells (IC50 was 8.82 and 9.01 µM), respectively. All the synthesized compounds exhibited low cytotoxicity against HUVEC cells. Further experiments proved that 5b could disturb the cell cycle in HepG-2 cells and induce apoptosis. In addition, the binding properties of a model conjugate 5b to DNA were investigated by methods (UV-Vis, fluorescence, CD spectroscopy). Results indicated that 5b showed moderate ability to interact ct-DNA.

Synthesis and pharmacological evaluation of novel bisindole derivatives bearing oximes moiety: identification of novel proapoptotic agents.

In an effort to develop potent anti-cancer chemopreventive agents, a novel series of bisindole derivatives bearing oxime moiety were synthesized. Structures of all compounds were characterized by NMR and HRMS. Anti-proliferative activities for all of these compounds were investigated by the method of MTT assay on 7 human cancer lines and the normal cell lines (HUVEC). Most of them showed a noteworthy anti-cancer activity in vitro, the half maximal inhibitory concentration (IC50) value is 4.31 µM of 4e against T24. The results from Hoechst 33258 and acridine orange/propidium iodide staining as well as annexinV-FITC assays provided evidence for an apoptotic cell death. The further mechanisms of compound 4e-induced apoptosis in T24 cells demonstrated that compound 4e induced the productions of ROS, and altered anti- and pro-apoptotic proteins, leading to mitochondrial dysfunction and activations of caspase-9 and caspase-3 for causing cell apoptosis. Moreover, the cell cycle analysis and western-blot analysis indicated that compound 4e effectively arrested T24 cells in G1 stage and possibly has an effect on cell cycle regulatory proteins particularly cyclin D1.

Design, synthesis and in vitro evaluation of novel ursolic acid derivatives as potential anticancer agents.

A series of novel ursolic acid (UA) derivatives modified at the C-3 and the C-28 positions were designed and synthesized in an attempt to develop potential antitumor agents. The in vitro cytotoxicity were evaluated against five cancer cell lines (MGC-803, HCT-116, T24, HepG2 and A549 cell lines) and a normal cell (HL-7702) by MTT assay. The screening results indicated that some of these target compounds displayed moderate to high levels of antiproliferative activities compared with ursolic acid and 5-fluorouracil (5-FU), and exhibited much lower cytotoxicity than 5-FU, indicating that the targeted compounds had selective and significant effect on the cell lines. The induction of apoptosis and affects on the cell cycle distribution of compound 6r were investigated by acridine orange/ethidium bromide staining, Hoechst 33258 staining, JC-1 mitochondrial membrane potential staining and flow cytometry, which revealed that the antitumor activity of 6r was possibly achieved through the induction of cell apoptosis by G1 cell-cycle arrest. Western blot and qRT-PCR (quantitative real-time PCR) experiments demonstrated that compound 6r may induce apoptosis through both of intrinsic and extrinsic apoptosis pathway.

Synthesis and antitumor activities of novel α-aminophosphonate derivatives containing an alizarin moiety.

A series of novel α-aminophosphonate derivatives containing an alizarin moiety (6-7) was designed and synthesized as antitumor agents. MTT (3-(4, 5-dimethylthiazol-2-yl)-2, 5-diphenyl tetrazolium bromide) assay results indicated that most compounds exhibited moderate to high inhibitory activity against KB, NCI-H460, HepG 2, A549, MGC-803, Hct-116, CNE and Hela tumor cell lines. The action mechanism of representative compounds 7h, 7j and 7n were investigated by fluorescence staining assays, flow cytometric analysis and real-time polymerase chain reaction (PCR) assays, which indicated that these compounds induced apoptosis and involved G1 phase arrest by increasing the production of intracellular Ca(2+) and reactive oxygen species (ROS) and affecting associated enzymes and genes. The results demonstrated that these compounds may induce apoptosis through a mitochondrion-dependent pathway.

Synthesis and biological evaluation of novel aniline-derived asiatic acid derivatives as potential anticancer agents.

Asiatic acid (AA) derivatives 4 and 5 modified at the C-11 and C-28 positions were designed and synthesized, their structures were confirmed using HRMS, (1)H NMR and (13)C NMR. In vitro antitumor activities of all compounds against MGC-803, NCI-H460, HepG2, Hela and 7404 cancer cell lines were evaluated and compared with commercial anticancer drug 5-fluorouracil (5-FU), employing standard MTT assay. The new compounds 5a-5t showed stronger anti-proliferative activity than AA, especially compound 5b was found to be the best inhibition activity on HepG2 cell line. In addition, the mechanism of compound 5b was preliminarily investigated by acridine orange/ethidium bromide staining, Hoechst 33258 staining, JC-1 mitochondrial membrane potential staining, flow cytometric, qRT-PCR (quantitative real-time PCR) and Western blot. Compound 5b induced the productions of ROS, and altered anti- and pro-apoptotic proteins, leading to mitochondrial dysfunction and activations of caspase-9 and caspase-3 for causing cell apoptosis. Moreover, the cell cycle analysis showed that compound 5b mainly arrested HepG2 cells in G1 stage.