Background:

IC50: 127 and 190 nM for enzyme and cell, respectively

Eg5-I is a potent inhibitor of Eg5.

The kinesin-like spindle protein Eg5, also known as KSP and Kif11, is a motor protein that is essential for establishing a bipolar spindle during mitosis.

In vitro: Previous study found that the interphase microtubule morphology was normal after the treatment of Eg5-I, whereas spindle morphology mirrored that of the parent compound. Eg5-I was tested for inhibitory activity against a selected panel of mitotic kinesins with no measurable inhibition detected. To determine whether Eg5-I had a similar effect on KSP dynamics, cells were treated with Eg5-I and probed for KSP localization with anti-KSP antibodies. Eg5-I showed a dose-dependent depletion of KSP from the spindle, with a 1.63-fold increase in clearance of KSP over its parent compound, consistent with the biochemical-and cell-based assays. Eg5-I blocked bipolar spindle formation, whereas the parent compound was weakly active. Eg5-I was also evaluated for anti-proliferative activity against the NCI60 tumor panel and the growth inhibitory concentration anged from 10 nM to 3 μM across the panel, respectively [1].

In vivo: Up to now, there is no animal in vivo data reported for Eg5-I.

Clinical trial: So far, no clinical study has been conducted for Eg5-I.

Reference:
[1] Rodriguez, D. ,Ramesh, C.,Henson, L.H., et al. Synthesis and characterization of tritylthioethanamine derivatives with potent KSP inhibitory activity. Bioorganic & Medicinal Chemistry 19(18), 5446-5453 (2011).