Gui-Yang Yao

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.

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, antiproliferative and apoptosis-inducing effects of novel asiatic acid derivatives containing α-aminophosphonates

A series of novel asiatic acid (AA) derivatives containing α-aminophosphonate were designed and synthesized as antitumor agents. In vitro antitumor activities of these compounds against five cancer cell lines (A549, Hct-116, T24, Spca-2 and SK-OV-3 cell) and a normal cell line (HUVEC cell) were evaluated, employing standard MTT assay. Antitumor activities screening result indicated that many target compounds displayed moderate to high levels of antitumor activities compared with AA, 5-fluorouracil (5-FU) and cisplatin, and exhibited much lower cytotoxicity against normal cell than 5-FU and cisplatin. In addition, the mechanism of representative compound 3d was preliminarily investigated by AO/EB staining, Hoechst 33258 staining, JC-1 mitochondrial membrane potential staining, flow cytometry and western blot. Compound 3d inducing apoptosis involved intracellular Ca2+ production, the loss of mitochondrial membrane potential and intracellular reactive oxygen species (ROS) production. Western blot analysis also demonstrated that compound 3d treatment triggered the mitochondrial apoptotic pathway, indicating by changing Bax/Bcl-2 ratios, cytochrome c release, and caspase-9 activation. Moreover, the cell cycle analysis showed that compound 3d may confine T24 cells in G1/S phase mainly through the p53-dependent pathway. Together, these results implied a critical role of ROS, caspase-9 and p53 in compound 3d-inducing G1/S arrest and apoptosis of T24 cells.

Synthesis and molecular docking study of novel alizarin derivatives containing phosphoryl amino acid moiety as potential antitumor agents

Series of novel alizarin and phosphoryl amino acid scaffold (4a–4d, 8a–8d) were synthesized and evaluated for the suppression of cancer cell proliferation in vitro against MGC-803, HepG2, T24, NCI-H460, and SK-OV-3 cell lines by standard 3-(4, 5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide (MTT) assay compared with commercial anticancer drug doxorubicin. Interestingly, all newly synthesized compounds exhibited relatively high cytotoxicity compared with alizarin and low cytotoxicity against human normal liver cell line HL-7702 cells. Especially, compound 8d showed the best cytotoxicity against SK-OV-3 cells with IC50 7.09 µM, which was slightly worse than that of drug doxorubicin. The cell apoptosis-inducing activity of representative compound 8d in SK-OV-3 cells revealed that the anticancer activity of this compound depended on apoptosis of cancer cells via regulation of Bcl-2 family members, activation of caspase-9 and caspase-3. Cell cycle analysis confirmed that compound 8d mainly arrested SK-OV-3 cells in G2 stage. In addition, molecular docking studies were performed to position compound 8d into the telomerase (5CQG) active site to determine the probable binding model.

Protonation-controlled axial chirality in maleopimaric imides

Maleopimaric N-naphthylimides (1–3) underwent slow aR–aS conversion and were induced in a gradual change of different [aR]/[aS] ratio during dissolution in various polar solvents at ambient temperatures. N-Quinoline-imides 2 with 28–100% ee of aR isomer were found to be protonation-controllable under hydrophobic condition. Mechanistic studies showed that this dramatic acid induced change was due to stabilization of the planar transition state by formation of an intramolecular hydrogen bond between the protonated quinoline nitrogen (N+–H) and an imide carbonyl (OC).