Novel hydroxamic acids incorporating 1-((1H-1,2,3-Triazol-4-yl)methyl)-3-hydroxyimino-indolin-2-ones: synthesis, biological evaluation, and SAR analysis

A series of seventeen novel hydroxamic acids incorporating 1-((1H-1,2,3-triazol-4-yl)methyl)-3-hydroxyimino-indolin-2-ones was designed and synthesized. Biological evaluation showed that these hydroxamic acids potently inhibited a class-I isoform of HDACs (HDAC2) with ${\text{IC}}_{50}$ values in low micromolar range. Several compounds also exhibited good cytotoxicity. Two compounds, 5e and 5f, emerged as the most potent HDAC2 inhibitors with cytotoxicity up to 8-fold more potent than SAHA in three human cancer cell lines, including SW620 (colon cancer), PC3 (prostate cancer) and AsPC-1 (pancreatic cancer). A molecular modeling approach has been carried out which revealed some structure-activity relationships. Further investigation on absorption, distribution, metabolism, excretion and toxicity (ADMET) suggested that compounds 5e and 5f, while showing potent HDAC2 inhibitory bioactivity, hold desirable characteristics for anticancer compounds.

GRAPHICAL ABSTRACT

Three series of novel hydroxamic acids incorporating 1-((1H-1,2,3-triazol-4-yl)methyl)-3-hydroxyimino-indolin-2-ones (4a-c, 5a-g, 6a-g) were synthesized. Biological evaluation showed that these hydroxamic acids potently inhibited HDAC2 with ${\text{IC}}_{50}$ values in low micromolar range. .