Substituent Effects in 3,3' Bipyrazole Derivatives. X-ray Crystal Structures, Molecular Properties and {DFT} Analysis.

The single crystal X-ray structure of new 1,1'-bis(2-nitrophenyl)-5,5'-diisopropyl-3,3'-bipyrazole, 1, is triclinic P , a = 7.7113(8), b = 12.3926(14), c = 12.9886(12) Å, a = 92.008(8), ß = 102.251(8), γ = 99.655(9)°. The structural arrangement is compared to that of 5,5'-diisopropyl-3,3'-bipyrazole, 5, whose single crystal structure is found tetragonal I41/a, a = b = 11.684(1), c = 19.158(1) Å. The comparison is also extended to the structures previously determined for 1,1'-bis(2-nitrophenyl)-5,5'-propyl-3,3'-bipyrazole, 2, 1,1'-bis(4-nitrophenyl)-5,5'-diisopropyl-3,3'-bipyrazole, 3, and 1,1'-bis(benzyl)-5,5'-diisopropyl-3,3'-bipyrazole, 4. Density Functional Theory (DFT) calculations are used to investigate the molecular geometries and to determine the global reactivity parameters. The geometry of isolated molecules and the molecular arrangements in the solid state are analyzed according to the nature of the groups connected to the bipyrazole core.

Anti-cancer effect of two alkaloids: 2R and 2S-bgugaine on mastocytoma P815 and carcinoma Hep.

The 2-alkylpyrrolidine R-bgugaine, a natural alkaloid isolated from tubers of Arisarum vulgare Targ. Tozz. (Araceae), and its isomer S-bgugaine, obtained by an asymmetric synthesis, were examined for their cytotoxic activities on two cancerous cellular lines: the murine mastocytoma cell line P815 and the human laryngeal carcinoma cell line Hep. These two alkaloids exhibited an important cytotoxic activity on these two cancerous cellular lines. The concentrations required to induce 50% of lysis (IC(50)) for R-bgugaine and S-bgugaine alkaloids were determined, and are 10 and 5 microg mL(-1), and 5 and 100 microg mL(-1), respectively, for the mastocytoma P815 and carcinoma Hep, compared with those of Adriamycine (5 microg mL(-1) for P815 cell line and 5 microg mL(-1) for Hep cell line), taken as positive controls.

New pyrazolic compounds as cytotoxic agents.

The evaluation of the in vitro cytotoxic properties of two pyrazole compounds: 1-(4-nitrophényl)-3,5-diméthylpyrazole (1) and 1,1'-di(4-nitrophényl)-5,5'-diisopropyl-3,3'-bipyrazole (2) was investigated against Hep cell line (Human laryngeal carcinoma). These two compounds showed an important cytotoxic activity on the Hep cell line, with IC(50): 8.25 microg mL(-1) for the compound 1; IC(50): 10.20 microg mL(-1) for the compound 2 while the IC(50) for adriamycine used as positive control was 3.62 microg mL(-1).

Anticancer effect of three pyrazole derivatives.

The evaluation of the cytotoxic properties in vitro of three synthetic tripods containing pyrazole: N,N-bis[(3,5-dimethylpyrazol-1-yl)methyl]aniline (1); N,N-tetrakis[(3,5-dimethylpyrazol-1-yl)methyl]-para-phenylenediamine (2); and N,N-tetrakis-[(1,5-dimethylpyrazol-3-yl)methyl]-para-phenylenediamine (3), was examined for their cytotoxic activity on two tumor cell lines: P815 (murin mastocytoma) and Hep (human laryngeal carcinome). While the compound 2 shows a small cytotoxic activity, compounds 1 and 3 are more cytotoxic against both cell lines. However, this cytotoxicity is more pronounced against Hep cell line (IC50: 3.25 microg mL(-1) for compound 1 and 6.92 microg mL(-1) for compound 3) than P815 cell line (IC50: 17.82 microg mL(-1) for compound 1 and 37.21 microg mL(-1) for compound 3). Statistical analysis shows that the compound 1 is two- to threefold more cytotoxic than compound 3 (P < 0.05). Interestingly, the cytotoxicity induced by compound 1 against Hep cell line is more important than that induced by adriamycin used as a positive control.