Synthesis and biological evaluation of novel hybrids of phenylsulfonyl furoxan and phenstatin derivatives as potent anti-tumor agents

Hybridization of nitric oxide (NO) donors with known anti-cancer agents have been emerged as a strategy to achieve improved therapeutic effect and to overcome chemo-resistance in cancer therapy. In this study, furoxan moiety as an efficient NO donor was introduced to phenstatin, a microtubule-interfering agent (MIA), leading to the design and synthesis of a series of furoxan-based NO-releasing arylphenones derivatives. In biological evaluation, the synthesized compounds showed moderate to potent anti-tumor activities against several human cancer cell lines. Among them, compound 15h showed the most potent activities against both chemo-sensitive and resistant cancer cell lines with IC₅₀ values ranging from 0.008 to 0.021 μM. Further mechanistic studies revealed that 15h worked as a bifunctional agent exhibiting both tubulin polymerized inhibition and NO-releasing activities, resulting in potent anti-angiogenesis, colony formation inhibition, cell cycle arrest and apoptosis induction effects. In the nude mice xenograft model, 15h significantly inhibited the paclitaxel-resistant tumor growth with low toxicity, demonstrating the promising potential for further preclinical evaluation as a therapeutic agent, particularly for the treatment of chemo-resistant cancers.