Biotranformation of cannabidiol by Cannabis sativa endophytic fungi

Endophytic fungi can perform a variety of chemical reactions as biocatalysts and are effectively one of the most inventive synthetic chemists. Despite being widely regarded as such, the potential of Cannabis sativa mycobiota to biotransform cannabinoids is still an underexplored area.

To this end, twenty-five endophytic fungi were isolated from C. sativa leaves, stems and flowers. All strains were cultivated in three different solid media and the endophytes showing the largest growth rate were chosen for evaluation of their cannabidiol (CBD) biotransformation potential. The strain with the most promising chemical profile was then subjected to a scaled-up liquid fermentation process for the isolation of fungal biotransformation products.

After seven days of fermentation the liquid broth was filtered and both the medium and the lyophilized mycelium were extracted with EtOAc. The extracts were chromatographed using CC and the biotransformation products were purified using semi-preparative RP-HPLC. Isolated compounds were characterized by the extensive use of 1 & 2D NMR and HRMS spectra.

The fungal endophyte under investigation, belonging to the genus Chaetomium produced several metabolites of CBD. Among them, one previously undescribed glycosidic derivative of CBD and four new compounds belonging to the cannabielsoin type cannabinoids were isolated. In addition to them, one known mono-hydroxylated, two di-hydroxylated and one O-glycoside were purified. An antibiotic namely chochliodinol, characteristic of the specific genus, was also isolated. To conclude, it seems that with the aid of endophytes from C. sativa, cannabinoids can be transformed into a large inventory of novel compounds with potential pharmaceutical applications.

Publication History

Article published online:
13 December 2021