Novel α-aminophosphonic acids. Design, characterization, and biological activity

Cytotoxic Activity of α-Aminophosphonic Derivatives Coming from the Tandem Kabachnik–Fields Reaction and Acylation

Encouraged by the significant cytotoxic activity of simple α-aminophosphonates, a molecular library comprising phosphonoylmethyl- and phosphinoylmethyl-α-aminophosphonates, a tris derivative, and N-acylated species was established. The promising aminophosphonate derivatives were subjected to a comparative structure–activity analysis. We evaluated 12 new aminophosphonate derivatives on tumor cell cultures of different tissue origins (skin, lung, breast, and prostate). Several derivatives showed pronounced, even selective cytostatic effects. According to IC50 values, phosphinoylmethyl-aminophosphonate derivative 2e elicited a significant cytostatic effect on breast adenocarcinoma cells, but it was even more effective against prostatic carcinoma cells. Based on our data, these new compounds exhibited promising antitumor activity on different tumor types, and they might represent a new group of alternative chemotherapeutic agents.

Carbene-Catalyzed [4 + 2] Cycloadditions of Vinyl Enolate and (in Situ Generated) Imines for Enantioselective Synthesis of Quaternary α-Amino Phosphonates

A carbene-catalyzed enantioselective addition of enals to five-membered cyclic imines is developed. The reaction gives chiral quaternary α-amino phosphonates bearing tetrasubstituted carbon centers with excellent enantioselectivities. The imine substrates can be generated in situ from the corresponding amines under an oxidative condition that is compatible with the carbene catalysis. Thus, a one-pot cross-dehydrogenative-coupling (CDC) reaction between enals and amines is also realized with high enantioselectivity remaining. The method provides quick enantioselective access to amino phosphonates with potential applications in medicines and pesticides.

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, 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.

A diastereo- and enantioselective synthesis of alpha-substituted anti-alpha,beta-diaminophosphonic acid derivatives

Highly diastereo- and enantioselective additions of alpha-nitrophosphonates to imines catalyzed by a chiral Brønsted acid are described.

Novel N-(phosphonomethyl) glycine derivatives: Design, characterization and biological activity

A series of Calpha,alpha-disubstituted cyclic derivatives of N-(phosphonomethyl) glycine have been synthesized and characterized. They exhibited moderate clastogenicity, low antiproliferative activity on mice bone marrow cells and well expressed cytotoxicity against human tumor cell lines. The 8- and 12-membered cyclic analogs proved superior to the remaining compounds and were found to trigger apoptotic cell death in DOHH-2 cells. The latter compound caused 50% inhibition of the viability of hemobastose-derived cell lines at concentrations ranging from 20 to 67 microM.

Synthesis, cytotoxicity and clastogenicity of novel α-aminophosphonic acids

Alpha-ethyl-N-(phosphonomethyl) glycine is synthesized and characterized by NMR and FAB spectroscopy. The cytotoxicity, clastogenic and antiproliferative effect of 3-ethyl-2-hydroxyl-2-oxo-1,4,2-oxazaphosphorinane, sodium salt of 3-ethyl-2-hydroxyl-2-oxo-1,4,2-oxazaphosphorinane, alpha-ethyl-alpha-N-(hydroxyethylamino) methylphosphonic acid, alpha-ethyl-N-(phosphonomethyl) glycine, alpha-ethyl-N-(phosphonomethyl) glycine isopropylammonium salt, glyphosate isopropylammonium salt are tested.