Novel microbial transformation of resibufogenin by Fusarium solani.

In this paper, microbial transformation of resibufogenin by Fusarium solani AS 3.1829 was investigated, and five transformed products were isolated and identified as 3-ketone-resibufogenin (2), 3-one-cyclic 3-(1,2-dimethyl-1,2-ethanediylacetal)-resibufogenin (3), 3-dimethoxyl-resibufogenin (4), 3-epi-resibufogenin (5), and 3-epi-15α-hydroxy-7βH-bufalin (6), respectively. Among them, 3, 4, and 6 are new compounds, and the rare double oxidization of C-3 was reported. In addition, the cytotoxicities of transformed products were also investigated.