Free radical scavenging activity and active metabolite profiling of endophytic fungi from Nothapodytes foetida and Hypericum mysorense

Background

Chemical diversity of endophytic fungi has made them an alternate source for bioactive compounds. Novel biotopes with promising bioactivity are expected from endophytes of medicinal plants from biodiversity hotspots. Therefore, endophytes of Nothapodytes foetida and Hypericum mysorense from Western Ghats, India were screened for free radical scavenging activity and anti-radical metabolites were profiled.

Methods

Endophytes were isolated from surface sterilized leaves, stems and barks of N. foetida and H. mysorense. Ethyl acetate extracts of culture filtrates were tested for antiradical activity using DPPH and ABTS free radicals. Antiradical spots on developed chromatogram were profiled by spraying with DPPH solution.

Results

A dose dependent antiradical activity of variable magnitude was observed. Fourteen isolates from H. mysorense and thirteen isolates from N. foetida showed significant antiradical activity. 55% of tested isolates exhibited more than 95% quenching of DPPH radicals and 40% recorded more than 75% scavenging activity. A total of 66.67% of the tested isolates recorded more than 95% scavenging of ABTS radicals and 29.6% showed more than 75% scavenging activity. TLC of active extracts showed the presence of a minimum three and maximum thirteen radical scavenging metabolite spots.

Conclusion

This is the first report on antiradical activity of endophytic isolates of H. mysorense. Active metabolite profiling would help in the further purification of most potent and abundant bioactive molecule from the fungal endophytic extracts. Further purification and characterization of the active metabolites may lead to the discovery of novel bioactive molecules of industrial and pharmaceutical importance.