In Arquebio, we’ve been testing different strains of fungi for their innate ability to produce valuable derivatives of oleanolic acid. Fungi possess a unique ability to generate hydroxylated derivatives of triterpene-related molecules, among other interesting interactions.

Recently, we discovered that the fungi Absidia cylindrospora transforms oleanolic acid into a variety of unidentified compounds, some of which might be hydroxylated derivatives. To our knowledge, there is no current scientific publication that describes this strain to be active on oleanolic acid, which could open the avenue for the discovery of new compounds.

Interestingly, when oleanolic acid and mycelium of Absidia cylindrospora are cultured together in complex liquid media, oleanolic acid appears to be mineralized (consumed) by the strain. However, if a simplified version of the liquid media is used, new compounds are detected. This was first tested on TLC, and subsequently, confirmed on HPLC.

Our underlying hypothesis is that under low nutrient conditions, the metabolic route towards mineralization of oleanolic acid is hampered, and by-products accumulate, some of which might be hydroxylated derivatives of oleanolic acid.


Figure 1. HPLC results. Blue: negative control (oleanolic acid, no mycelium). Red: negative control (no oleanolic acid, with mycelium). Green: oleanolic acid and mycelium cultured in simplified liquid media. 7 new peaks were identified.