The synthesis and activity evaluation of N-acylated analogs of echinocandin B with improved solubility and lower toxicity

Presently, echinocandins have been recommended as the first-line drugs for the treatment of invasive candidiasis. However, low oral bioavailability and solubility limit their application. To improve this situation, this study chose amino acid and fatty acid as raw materials to modify the nucleus of echinocandin B. Six N-acylated analogs were screened from the derivatives that possessed potent antifungal activity and good water solubility. Based on antifungal susceptibility and hemolytic toxicity, compound5as the candidate had good antifungal activity and no hemolytic effect. Moreover, compared with anidulafungin, compound5showed a comparable fungicidal effect, much higher solubility, and lower toxicity. In conclusion, compound5has the potential for further research and development on account of reserved antifungal activity, high solubility, and low toxicity.