- Cytotoxic effect of amide derivatives of trifluoromethionine against the enteric protozoan parasite Entamoeba histolytica
-
Amoebiasis, caused by infection with the enteric protist Entamoeba histolytica, is one of the major parasitic diseases. Although metronidazole and its derivatives are currently employed in therapy, the paucity of effective drugs and potential clinical resistance necessitate the development of a novel drug. Trifluoromethionine (TFM) is a promising lead compound for antiamoebic drugs. To potentiate the antiamoebic effect of TFM, we synthesised various amide derivatives of TFM and evaluated their cytotoxicity. The amide derivatives of TFM were observed to have a superior cytotoxic effect compared with TFM and metronidazole against E. histolytica in vitro. Although TFM showed cytotoxicity following degradation by methionine γ-lyase, the derivatives were degraded by the enzyme less efficiently compared with TFM. We further demonstrated that a representative derivative was hydrolysed by the amoebic cell lysate to first yield TFM, followed by degradation similar to TFM. Hydrolysis was partially inhibited by protease inhibitors. A single subcutaneous or oral administration of TFM and its amide derivatives also effectively prevented the formation of amoebic liver abscess in a rodent model. These data demonstrate the improved effectiveness of TFM derivatives against E. histolytica infection and elucidate the mechanisms underlining the mode of action of these compounds.
- Sato, Dan,Kobayashi, Seiki,Yasui, Hiroyuki,Shibata, Norio,Toru, Takeshi,Yamamoto, Masaichi,Tokoro, Gensuke,Ali, Vahab,Soga, Tomoyoshi,Takeuchi, Tsutomu,Suematsu, Makoto,Nozaki, Tomoyoshi
-
-
Read Online
- Thiocarbonyl Fluoride in the Solvent System Hydrogen Fluoride: Preparation and Reactions of Halogenated Thiocarbenium Ions
-
Solvolysis of thiocarbonyl fluorides 1b, c in HF/SbF5 or FSO3H/SbF5 yields dithietane-2-ylium ions 2b, c, respectively.Reactions of 2b, c with the base F in the solvent system HF give the dithietanes 3b, c.The acidity dependance of the formation of 2b, c is demonstrated by gradation of the acidic strength with NbF5 and F(1-).The existence of thioacylium ions 5b, c in solutions of extremely high acidity is concluded from NMR spectroscopic data.The results of the solvolysis reactions are confirmed by thioacylation of the aromatic compounds 6a-d in the HF system leading to trifluoromethyl dithiobenzoates 7a-d.Among the corresponding carbonyl fluorides only 4 exhibits comparable basic properties in superacids.
- Haas, Alois,Wanzke, Wolfgang
-
p. 429 - 434
(2007/10/02)
-
- Photochemical Behaviour of Bis(trifluoromethylthiyl)trithiocarbonate in Solution
-
Bis(trifluoromethylthiyl))trithiocarbonate showes electronic transitions at 496 nm (n?*), 299 nm (??*) and 259 (n?*).Photolysis with 254 and 300 nm light at 200 and 309 K in pentane, and at 371 K in heptane yields a mixture of CS2 and perfluorinated compounds such as F3CSCF3, F3CSSCF3, (F3CS)3C-C(SCF3)3, (F3CS)2C=C(SCF3)2, (F3CS)3CH and F3CS-substituted solvent.The concentration of these newly formed products versus time of irradiation has been monitored.The primary photochemical process is the intramolecular decomposition into CS2 and F3CS and F3C radicals which dimerize in a solvent cage.The formation of (F3CS)3C-C(SCF3)3 is interpreted in terms of a competition between this combination process and trapping of trifluoromethyl radicals by (F3CS)2CS, forming (F3CS)3C, which subsequently dimerizes.On irradiation at 496 nm (n?*) no photochemical process has been observed. - Key words: Bis(trifluoromethylthiyl)trithiocarbonate, Electronic Spectra, Photochemical Behaviour, Tris(trifluoromethylthiyl)methyl Radical
- Schlosser, Karl
-
p. 172 - 178
(2007/10/02)
-