Metabolomics-guided identification of compounds with antibacterial and antioxidant activities from Polygonatum sibiricum -derived endophytic fungi

Background Infections caused by multidrug resistant bacterial pathogens have been recognized as major global healthcare threat to medicinal, agricultural and pharmaceutical industries by World Health Organization. In this regard, the present study was aimed to isolate endophytes from medicinal plant Polygonatum sibiricum ( P. sibiricum ) and to investigate their antibacterial efficacy, radical scavenging ability and chemical fingerprinting using Gas Chromatography–Mass Spectrum (GC–MS) analysis. Results Two endophytic fungi Talaromyces assiutensis HJ.14 ( T. assiutensis ) and Fusarium oxysporum HJ.15 ( F. oxysporum ) were isolated and identified from the rhizomes of P. sibiricum . Among the extracts screened, ethyl acetate extract of F. oxysporum HJ.15 showed maximum antibacterial activity with the zones of inhibition ranging from 10.98 ± 0.19 to 15.66 ± 1.49 mm and the MIC values ranging from 0.24 to 1.88 µg/mL against the tested bacterial pathogens. In addition, it showed significant antioxidant activity with EC 50 values of 6.21–17.97 µg/mL. Further, GC–MS analysis revealed the presence of propanoic acid ethyl ester, hexadecanoic acid methyl ester, hexadecanoic acid ethyl ester, 9-Octadecenoic acid (Z)-methyl ester, 1-Octanol, 2-Undecenal, butanoic acid, 3-hydroxy- and hexanoic acid were the most abundant compounds in the active crude extract which was responsible for the significant antibacterial and antioxidant properties. Conclusions In summary, our results clearly suggest that the F. oxysporum HJ.15 will be a promising starting point for the isolation of active antibacterial compounds with antioxidant properties.