Hirschioporus fuscoviolaceus is a commonly distributed saprotrophic fungus across
the coniferous forests of temperate regions. An in-depth chemical analysis of the
methanol extract of H. fuscoviolaceus resulted in the isolation of four compounds
(1−4). The four fungal metabolites were identified as ergosterol peroxide (1), 5α,8α-epidioxy-ergosta-6-en-3β-ol
(2), β-sitosterol (3) and 9,11-dehydro-ergosterol peroxide (4), that latest was isolated
as a mixture with its closely related compound, ergosterol peroxide (1). The structure
identification of the isolated compounds was carried out by one- and two-dimensional
NMR and MS analysis. The antimicrobial properties of the fungal secondary metabolites
were investigated on several pathogens including Bacillus subtilis, Rhodococcus fascians,
Xanthomonas euvesicatoria, and Fusarium graminearum. According to our results, among
the identified ergostane-type sterols only mixture of compounds 1 and 4 exhibited
moderate inhibitory activity on Bacillus subtilis and Rhodococcus fascians. For the
examination of their potential α-glucosidase, lipase and acetylcholinesterase inhibition
activities, dot-blot enzyme assays were performed which highlighted that compounds
1−4 have considerable α-glucosidase inhibitory property, with the most active isolates
of 3 and 4, while compounds 1, 2 and 4 demonstrated notable activity against acetylcholinesterase.
The current study represents the first report on the chemical profile of H. fuscoviolaceus,
providing a comprehensive study on the isolation and structure elucidation of the
most important secondary metabolites and their potential biological activities.
