Novel Propofol Analogs: Design, Synthesis and Evaluation of Dihydrobenzofuran Derivatives as General Anesthetics.

Background

Propofol is used worldwide as a short-acting intravenous anesthetic in clinical practice; however, side effects such as injection pain and respiratory depression remain clinically relevant. Therefore, identification of safer propofol analogs is required. Method: In response to the urgent need for optimized potency and reduced side effects, a series of dihydrobenzofuran derivatives were designed as expectedly better propofol analogs through conformational restriction. A loss of righting reflex assay was conducted to evaluate the sedative/anesthetic properties of the synthesized compounds, and a respiratory depression test was performed for safety assessment.

Results

Most of the designed compounds were shown to possess promising anesthetic properties as propofol analogs. The represented 53A had higher potency and a wider safety margin (ED50:3.898 vs. 8.040 mg/kg in mice; 2.985 vs. 5.894 mg/kg in rats; TI (therapeutic index): 6.172 vs. 5.061 in mice; 4.362 vs. 2.580 in rats) than propofol, and fast onset and recovery times were maintained. The phosphate prodrug 56A also exhibited better efficiency and safety than fospropofol, along with a longer duration and faster recovery time in sedative profiles. Furthermore, alleviation of the adverse effects of respiratory depression has been demonstrated.

Conclusions

53A has the potential to be selected as a preclinical candidate for clinical development.