Biotransformation of triptolide by Cunninghamella blakesleana

Biotransformation of triptolide by Cunninghamella blakesleana (AS 3.970) was carried out. Seven biotransformation products were obtained and four of them were characterized as new compounds. On the basis of their NMR and mass spectral data, their structures were characterized as 5α-hydroxytriptolide , 1β-hydroxytriptolide , triptodiolide , 16-hydroxytriptolide , triptolidenol , 19α-hydroxytriptolide and 19β-hydroxytriptolide . All the new transformed products ( and ) were found to exhibit potent in vitro cytotoxicity against some human tumor cell lines.