[Two types of MWNTs with different surface modifications induce differential expression of proteins in RAW264.7 cells].

OBJECTIVE: To compare the different expression of protein in RAW264.7 macrophage cells induced by two types of MWNTs (multi-walled carbon nanotubes) with different surface modifications (acid-treated MWNTs and tau-MWNTs modified by taurine). METHODS: Treating cells with both types of MWNTs in 20 mg/L and 24 h, with a blank-control group set. Cells are lysed by using urea and by ultrasonicating in ice bath, then total proteins of cells are extracted. Using two-dimensional gel electrophoresis to separate total proteins of cells, searching for the differential expressed protein spots on the images of the gels with silver staining. Identifying the differentially expressed proteins via mass spectrometry, and studying the mechanism of effects on cells imposed by two types of MWNTs at protein level. RESULTS: There are 13 spots of protein with notably differential expression among three treated groups (including blank controls). Their functions involve apoptosis-related, calcium-binding, cell-cycle related, DNA synthesis, folding of proteins, and energy metabolism, etc. The results are consistent with our previous studies about the cytotoxicity of Both types of MWNTs including induction of apoptosis and mitochodira damage. CONCLUSION: Both two types of MWNTs could induce alteration of protein expression in RAW264.7 cells. With different surface modifications, they imposed different effects. High throughout proteomics could be applied in toxicity assessment and mechanism investigation about carbon nanotubes.

Synthesis, fungicidal activity, and QSAR of pyridazinonethiadiazoles.

A series of novel 5-[1-aryl-1,4-dihydro-6-methylpyridazin-4-one-3-yl]-2-arylamino-1,3,4-thiadiazoles, related to the fungicidal activity, were synthesized and tested in vivo against wheat leaf rust, Puccinia recondita. The preliminary bioassay indicated that they exhibited fungicidal activity and the activity was influenced by the nature of the substituents. A quantitative structure-activity relationship study showed that the hydrophobicity (Sigma(pi)) is a major positive parameter in affecting the activity; the electronic parameters (Sigmasigma, SigmaF) are the major negative parameters in affecting the activity. Especially, introducing an ortho substituent with an inductively electron-donating property is favorable to the activity.

Synthesis, fungicidal activity, and 3D-QSAR of pyridazinone-substituted 1,3,4-oxadiazoles and 1,3,4-thiadiazoles.

A series of novel 5-[1-aryl-1,4-dihydro-6-methylpyridazin-4-one-3-yl] -2-arylamino-1,3,4-oxadiazoles, fungicidally active, were synthesized based on bioisosterism and tested in vivo against wheat leaf rust, Puccinia recondita. These compounds were shown to be fungicidally active, and their activity was influenced by the nature of the substituents. By using the three-dimensional quantitative structure-activity relationships (3D-QSAR) method of comparative molecular field analysis (CoMFA), we have studied the structure and activity relationship of the compounds containing both pyridazinone-substituted 1,3,4-thiadiazoles and pyridazinone-substituted 1,3,4-oxadiazoles. The 3D-QSAR modes gave good correlation between the variations on percent inhibition and the steric-electrostatic properties. The results are consistent with a common mode of action for the pyridazinone-substituted 1,3,4-thiadiazoles and the pyridazinone-substituted 1,3,4-oxadiazoles, which further confirms that the 1,3,4-oxadiazole ring is a bioisosteric analogue of the 1,3,4-thiadiazole ring. These offer important structural insights into designing highly active compounds prior to their synthesis.