AUTHOR=Leylaie Sahar , Zafari Doustmorad 

TITLE=Antiproliferative and Antimicrobial Activities of Secondary Metabolites and Phylogenetic Study of Endophytic Trichoderma Species From Vinca Plants

JOURNAL=Frontiers in Microbiology

VOLUME=9

YEAR=2018

URL=https://www.frontiersin.org/journals/microbiology/articles/10.3389/fmicb.2018.01484

DOI=10.3389/fmicb.2018.01484

ISSN=1664-302X

ABSTRACT=<p>Endophytic fungi have been recognized as a potential source of bioactive secondary metabolites. The endophytic <italic>Trichoderma</italic> species were isolated from <italic>Vinca</italic> plants (<italic>Vinca major, Vinca herbacea</italic>, and <italic>Vinca minor</italic>), found in Iran and screened for antimicrobial and anti-proliferative activity. Based on morphological and phylogenetic analyses, four fungal species were identified: <italic>T. asperellum, T. brevicompactum, T. koningiopsis, and T. longibrachiatum</italic>. In addition, endophytic fungi bioactivity of methanol and ethyl acetate extracts (7.8–250 μgml<sup>−1</sup>) were assessed against a panel of pathogenic fungi and bacteria and IC<sub>80</sub> was calculated. Data showed that both methanol and ethyl acetate extracts from all endophytic isolates had significant cytotoxic effects against the model target fungus <italic>Pyricularia oryzae</italic>. Further research indicated that they had significant antimicrobial bioactivity against the human pathogenic bacteria <italic>Staphylococcus aureus</italic> and <italic>Escherichia coli</italic>, and plant pathogenic bacteria <italic>Ralstonia solanacearum</italic> and <italic>Clavibacter michiganensis</italic> as well. According to the bioactivity results, crude ethyl acetate extract of <italic>T. koningiopsis</italic> VM115 isolate was determined for TLC and GC-MS analysis. An antifungal compound was isolated from ethyl acetate extract of <italic>T. koningiopsis</italic> VM115 based on bioassay guided fractionation. The <sup>1</sup>H-NMR and <sup>13</sup>C-NMR spectroscopic data showed that the compound was trichodermin, which exhibited strong fungicidal effects against <italic>P. oryzae, Aspergillus fumigatus</italic>, and <italic>Botrytis cinera</italic> with MICs of 31.25 μg ml<sup>−1</sup> through <italic>in vitro</italic> antifungal tests. GC-MS analysis identified six classes of volatile compound produced by <italic>T. koningiopsis</italic> VM115 (alcohols, esters, pyrones (lactones), acids, furanes and lipids). 6-n-pentyl-6H-pyran-2-one (6PP) was identified as one of the most abundant metabolites in this research. These results indicate that the fungal endophytes from <italic>Vinca</italic> plants had antibacterial and cytotoxic activities; evidence that endophytes are a good source of biological activity and compounds. This work is the first report of Trichodermin production by <italic>T. koningiopsis</italic> species.</p>