一种新型第二代 C 端 Hsp90 抑制剂，Hsp90α 和 Hsp90β 的 Kd 分别为 191 uM 和 726 uM。

PU-H71 HCl (Zelavespib HCl) is a novel Hsp90 inhibitor, a novel purine-based analog, and a radiosensitizer that may be a promising agent for CIRT. PU-H71 HCL shows antitumor activity in many preclinical models of malignancy. PU-H71 HCL has an inhibitory effect on the protein expression levels of Rad51 and Ku70, which may be associated with the double chain break repair in the homologous recombination pathway and non-homologous end-joining pathway.

JG-98 是一种变构 Hsp70 抑制剂，对乳腺癌细胞系 MDA-MB-231 和 MCF-7 的活性和稳定性比 MKT-077 高 3 倍以上（EC50 分别为 0.4 uM 和 0.7 uM）。