20114-14-1

The mitotic spindle, a highly dynamic structure composed of microtubules, mediates the segregation of the previously duplicated genome into the two nascent daughter cells. Errors in this process contribute to pathology including tumor formation. Key for the shape and function of the mitotic spindle are kinesins, molecular motor proteins that convert chemical energy into mechanical work. Due to their fast mode of action, small molecules are valuable tools to dissect the dynamic functions of kinesins during mitosis. In this study, we report the identification of optimized small molecule inhibitors of the mitotic kinesin Kif18A. Using BTB-1, the first identified Kif18A inhibitor, as a lead compound, we synthesized a collection of derivatives. We demonstrate that some of the synthesized derivatives potently inhibited the ATPase activity of Kif18A with a half maximal inhibitory concentration (IC50) value in the low micromolar range. In vitro analysis of a panel of Kif18A-related kinesins revealed that the two most potent compounds show improved selectivity compared to BTB-1. Structure-activity relationship studies identified substituents mediating undesired inhibitory effects on microtubule polymerization. In summary, our study provides key insights into the mechanism of action of BTB-1 and its analogs, which will have a great impact on the further development of highly selective and bioactive Kif18A inhibitors. Since Kif18A is frequently overexpressed in solid tumors, such compounds are not only of great interest for basic research but also have the potential to open up new strategies for the treatment of human diseases.

This paper presents a series of first- and second-generation click-modified coumarin-based fluorescent probes for thiols. These molecules demonstrate high turn-on fluorescent response and good selectivity towards aromatic thiols over other relevant reactive sulfur species, reactive oxygen species and common nucleophiles. Moreover, probe 1a can detect thiols in the reduced rabbit plasma sample. Therefore, this approach provides a particularly impressive tool for detecting thiol in biological systems. Science China Press and Springer-Verlag Berlin Heidelberg 2012.

This study reports a benzothiazole-based fluorescent probe with simple structure for thiols. This probe exhibited high on/off signal ratios and good selectivity toward thiols over other analytes, and was successfully applied to the imaging of thiols in living cells.

A rapid response to thiophenols is obtained with probe 1 (see scheme), which induces a significant (> 50-fold) fluorescence enhancement as a result of cleavage of the electron-withdrawing moiety, thus generating strongly fluorescent molecule 2. No fluores

An efficient procedure for preparation of various sulfides has been introduced through a simple reaction of disulfides with suitable alkyl or aryl halides which is promoted by commercial zinc powder in the presence of AlCl3 in aqueous media at 65°C.

A novel application of linear free energy relationships is described in which the substrate selectivities and pH dependencies of glutathione S-transferases (GSTs) are correlated to the pK(a), of glutathione (GSH) at the active site. To determine whether t

Thiophenoxide ions supported on Amberlite IRA-900 (chloride from) have been treated with arylalkyl halides as well as with aryl helides to get sulphides which are useful in crop protection.Isolation of pure products by simple filtration and evaporation is an important feature of this method.

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