Biotransformations of Imbricatolic Acid by Aspergillus niger and Rhizopus nigricans Cultures

Guillermo Schmeda-Hirschmann, Carlos Aranda, Marcela Kurina, Jaime Rodríguez, Cristina Theoduloz
2007 Molecules  
Microbial transformation of imbricatolic acid (1) by Aspergillus niger afforded 1α-hydroxyimbricatolic acid (2), while transformation with Rhizopus nigricans yielded 15hydroxy-8,17-epoxylabdan-19-oic acid (3). When the diterpene 1 was added to a Cunninghamella echinulata culture, the main products were the microbial metabolites mycophenolic acid (4) and its 3-hydroxy derivative 5. All the structures were elucidated by spectroscopic methods. The cytotoxicity of these compounds towards human lung
more » ... towards human lung fibroblasts and AGS cells was assessed. While 4 and 5 showed low cytotoxicity, with IC 50 values > 1000 µM against AGS cells and fibroblasts, 1α-hydroxyimbricatolic acid (2) presented moderate toxicity towards these targets, with IC 50 values of 307 and 631 µM, respectively. The structure of 2 is presented for the first time.
doi:10.3390/12051092 pmid:17873843 fatcat:fzeeeu43z5cvzkghjnk4kpfrju