Endophytic fungus Paecilomyces formosus LHL10 produces sester-terpenoid YW3548 and cyclic peptide that inhibit urease and α-glucosidase enzyme activities.

Endophytic fungi have been used to obtain novel bioactive secondary metabolites with potential applications in medical and agricultural sectors, which can also act as lead targets for pharmaceutical and medicinal potential. In the present study, the endophytic fungus Paecilomyces formosus LHL10 isolated from the root of cucumber plant was tested for its enzyme inhibitory potential. The ethyl acetate (EtOAc) extract of LHL10 was screened for its inhibitory effect on acetylcholinesterase (AChE), α-glucosidase, urease, and anti-lipid peroxidation. The findings suggest that the EtOAc extract from LHL10 possesses significant inhibitory potential against urease and α-glucosidase. The EtOAc extract was thus, subjected to advanced column chromatographic techniques for the isolation of pure compounds. The structure elucidation was carried out through spectroscopic analysis and comparison with literature data, and these compounds were confirmed as known a sester-terpenoid (1) and a known cyclic peptide (2). The enzyme inhibition bioassay indicated that Compounds 1 and 2 exhibited remarkable inhibitory rate against α-glucosidase and urease, with an IC50 value of 61.80 ± 5.7, 75.68 ± 6.2 and 74.25 ± 4.3, 190.5 ± 10.31 µg/g, respectively. Thus, the current study concludes the enzyme inhibitory potential of endophyte LHL10 and provides the basis for further investigations of bioactive compounds, which could be used as potent drugs for enzyme inhibition.