Discovery of novel cosmeuceutical agents from endophytic microorganisms of Spanish biodiversity

In order to explore the potential of endophytic microorganisms to produce secondary metabolites with applications in the cosmeceutical industry, more than 120 potential candidate endophytic fungi and actinomycetes originated from Spanish biodiverse arid areas were selected to be studied. In order to broadly express the production of different secondary metabolites, four nutritional conditions have been used for the cultivation of the selected strains in liquid media. In total 1120 extracts have been generated and cell-based bioassays have being incorporated for the evaluation of their skin-protecting and skin-whitening activity. The whitening activity was determined using the tyrosinase assay, while the skin-protecting activity was determined by evaluating the elastase inhibitory activity. Among the initial 1120 extracts, approximately 30 were selected as promising bioactive samples and have been further evaluated in cell-based assays for their skin whitening (bleaching) activity in mouse melanocytes (B16F10 cell line), as well as for elastase inhibition in normal human fibroblasts (BJ cells). In parallel cytotoxicity evaluation (MTT method at the MCF-7 and HepG2 cell lines) was performed to the selected bioactive extracts in order to exclude those that exert cytotoxic effects. UHPLC-HRMS in bioactive extracts was used for profiling and metabolomics analysis in order to correlate the different secondary metabolites produced with each production condition and with the activity that each strain demonstrated. In addition a dereplication campaign for identification of known metabolites using commercial databases was performed. The non-cytotoxic extracts that demonstrated significant activity in both cell-free and cell-based assays have been selected for cultivation in larger scale and bioguided fractionation and isolation of bioactive compounds using both classical chromatographic methods (HPLC, MPLC), as well as innovative techniques, like SFC-MS and FCPC has been performed. The full set of spectroscopic data (MS and NMR) were recorded for all isolated compounds in order to unambiguously elucidate their structure.