ER-30346

Phosphonooxymethyl prodrugs of the broad spectrum antifungal azole, ravuconazole: synthesis and biological properties

Synthesis of phosphonooxymethyl derivatives of ravuconazole, 2 (BMS-379224) and 3 (BMS-315801) and their biological evaluation as potential water-soluble prodrugs of ravuconazole are described. The phosphonooxymethyl ether analogue 2 (BMS-379224) and N-phosphonooxymethyl triazolium salt 3 (BMS-315801) were both prepared from ravuconazole (1) and bis-tert-butyl chloromethylphosphate, but under two different conditions. Both derivatives were highly soluble in water and converted to the parent in alkaline phosphatase, and also in vivo (rat). However, BMS-315801 was found to be less stable than BMS-379224 in water at neutral pH. BMS-379224 (2) has proved to be one of the most promising prodrugs of ravuconazole that we tested, and it is currently in clinical evaluation as an intravenous formulation of the broad spectrum antifungal azole, ravuconazole.

3-Phenyl-5-acyloxymethyl-2H,5H-furan-2-ones: synthesis and biological activity of a novel group of potential antifungal drugs

3-(Substituted phenyl)-5-acyloxymethyl-2H,5H-furan-2-ones related to the natural product (-)incrustoporine were synthesized and their in vitro antifungal activity evaluated. The compounds with halogen substituents on the phenyl ring displayed much higher antifungal effect against Aspergillus fumigatus than selected representatives of azole antifungal drugs. In particular, the activity (1.34 microg/mL) of the most promising derivative, 3-(3,4-dichlorophenyl)-5-pivaloyloxymethyl-2H,5H-furan-2-one, was comparable to that of amphotericin B (0.5 microg/mL). Preliminary evaluation of the toxicity of the compound was carried out as well. Considering the size and properties of these molecules in comparison with those of amphotericin B, further development of this novel group of antifungals may lead to substances with better pharmacological profiles than that of the standard anti-Aspergillus drug.