Detection of withanolides produced by endophytic fungi isolated from the guitite tree (Acnistus arborescens) using ultra-high-performance liquid chromatography coupled with time-of-flight mass spectrometry

The relationship between the plant and the endophytic fungus goes beyond sharing a space and a means of nutrition. This similarity was confirmed in the secondary metabolites, withanolides, present both in the guitite and in endophytic fungi isolated from it. To detect the presence of the species, the cultivation of inocula from the bark, leaves, and stem was performed in triplicate, followed by extraction and analysis of the extracts using direct infusion mass spectrometry (DIMS) and ultra-high-performance liquid chromatography coupled with time-of-flight mass spectrometry (UPLC-ESI-Q-ToF/MS). Witafisalino I was precisely determined in samples GCH1-2 and GCH1-3, indicating that these are equivalent samples containing the species in the leaves of the shrub. Additionally, in strain GCC7, Fisanolido A was detected, which is a metabolite found in the bark of species from the Solanaceae family. The standard deviation in all measurements was less than 1.0%. This is considered a significant contribution, as guitite is a native species of Costa Rica and has been scarcely analyzed from this perspective. It recognizes new possibilities and contributions to research conducted on the similarity of metabolites with anticancer and antioxidant properties, such as those evaluated in withanolides