Synthesis and antifungal activity of bile acid-derived oxazoles

• Fourteen new bile acids oxazoles derivatives were synthesized.
• The antifungal activity of the starting acids and the products was assayed.
• The oxazole derivatives were more active than the starting bile acids.

Peracetylated bile acids (1a–g) were used as starting materials for the preparation of fourteen new derivatives bearing an oxazole moiety in their side chain (6a–g, 8a–g). The key step for the synthetic path was a Dakin–West reaction followed by a Robinson–Gabriel cyclodehydration. A simpler model oxazole (12) was also synthesized. The antifungal activity of the new compounds (6a–g) as well as their starting bile acids (1a–g) was tested against Candida albicans. Compounds 6e and 6g showed the highest percentages of inhibition (63.84% and 61.40% at 250 μg/mL respectively). Deacetylation of compounds 6a–g, led to compounds 8a–g which showed lower activities than the acetylated derivatives.