Eloi T. Cesar

Impact of the carbon chain length of novel platinum complexes derived from N-alkyl-propanediamines on their cytotoxic activity and cellular uptake.

This work describes the synthesis and characterization of four new ligands derived from 1,3-propanediamine in addition to the preparation and characterization of their respective platinum(II) complexes by reaction with K(2)PtCl(4). These ligands were obtained by the reaction of the corresponding alkyl mesylate with 1,3-propanediamine. We have prepared compounds having different carbon chains lengths in an attempt to correlate this factor, which influences the lipophilicity of the compounds, with cytotoxic activity. Octanol/water partition coefficients, the effect of the four complexes on the growth of two tumoral cell lines, and their cellular uptake were investigated. Increasing lipophilicity enhances the rate of cellular uptake and, consequently, the cytotoxic activity.

Synthesis of platinum complexes from N-benzyl ethylenediamine derivatives

O ligante N-benziletilenodiamina e derivados foram preparados em bons rendimentos utilizando-se metodologia diferente da descrita na literatura. Espectros de RMN de 1H e de 13C foram empregados para a caracterizacao destes compostos. Nove novos complexos de platina(II) com estes ligantes, analogos da cisplatina e da carboplatina, foram preparados e caracterizados. Testes preliminares in vitro em linhagens celulares de carcinoma bucal humano (celulas KB) indicam que estes complexos sao citotoxicos.

Synthesis, electrochemistry, and molluscicidal activity of nitroaromatic compounds: effects of substituents and the role of redox potential

Abstract-Molluscicidal bioassays and electrochemical studies (measurement of first wave reduction potential, Epcl) were performed on several synthetic nitroaromatics, in relation to possible correlation between biological activity, redox potential and structural effects. Five of them presented a significant molluscicidal activity on Biomphalaria glabrata (LD50 < 20 ppm). The Epc1 values ranged from -0.532 to -0.857 V versus Ag/AgCl (0.1 M) (-0.260 to -0.585 V versus NHE), all of them, in the favorable range for reduction in vivo. Data comparison between Epc1 and molluscicidal activity indicates that the presence of the electroactive nitro group is important for the biological activity. Correlation with redox potential, however, was not evident. Structural effects seem to be the most important parameter. Higher activity is noticeable for phenols, including the para-nitro azo or hydrazo-containing compounds. No activity was observed for compounds having the benzylic substituent in meta position to the nitro group. These results suggest that activity undoubtedly involves more than reduction characteristics and that the possible formation of electrophilic species, after nitro reduction, can play an important role in molluscicidal activity against B. glabrata.

Synthesis of Platinum Complexes from Sugar Derivatives

ABSTRACT Six new platinum(II) complexes containing a diamino sugar, analogs of cisplatin and carboplatin, have been prepared and characterized. The new ligands were obtained by reaction of D-galactose and D-ribose derivatives with ethylenediamine.

Synthesis, characterization, and cytotoxic activity of novel platinum (II) complexes derived from n-benzyl-ethylenediamine and oxalate.

This work describes the synthesis and characterization of three novel complexes derived from N‐benzyl‐ethylenediamine and oxalate. Precursor compounds were synthesized by reacting N‐benzyl‐ethylenediamine with K2PtCl4. Subsequent substitution of chlorides by oxalate led to the final products. Elemental analysis and the infrared, 1H, 13C, and 195Pt NMR spectra of these complexes were provided. The cytotoxic activities were investigated against human non‐small cell lung carcinoma (A549), mouse non‐metastatic cell skin melanoma (B16‐F1), mouse metastatic cell skin melanoma (B16‐F10), human cell breast adenocarcinoma (MDA‐MB‐231) and normal cell lines such as baby hamster cell kidney (BHK‐21), hamster cell ovary (CHO) and compared to cisplatin and carboplatin under the same experimental conditions. The presence of oxalate as a leaving group conferred an interesting cytotoxicity profile to the complexes in the tested cell lines.

Synthesis and characterization of platinum(II) complexes from trifluoromethyl phenylenediamine, picoline and N-benzyl ethylenediamine derivatives

Este trabalho descreve a sintese e a caracterizacao de onze novos complexos de platina(II), contendo como ligantes derivados da 1,2-fenilenodiamina, da N-benzil etilenodiamina, e da 2- ou 4-picolina. Os complexos foram preparados em rendimentos satisfatorios pela reacao dos ligantes com K2[PtCl4]. E descrita tambem a atividade citotoxica de um dos complexos de platina(II), em sete linhagens de celulas tumorais de origem humana, que se mostrou muito menos ativo do que a cisplatina.

Synthesis of Platinum Complexes from N-Benzyl-1,3-Propanediamine Derivatives, Potential Antineoplastic Agents

This work describes the synthesis of seven new platinum complexes having N-benzyl 1,3-propanediamine derivatives as ligands. They were prepared by the reaction of K2[PtCl4] with the appropriate ligand in water. These complexes are analogs of cisplatin, and are potential antineoplastic agents.

Synthesis of platinum complexes from N-benzyl-2-aminoethanethiol derivatives.

Twelve new platinum(II) complexes, analogs of cisplatin, containing a 2-aminoethanethiol N-substituted by several benzyl groups have been prepared and characterized in good yields. The ligands were obtained by reaction between 2-aminoethanethiol hydrochloride and different benzyl halides