Inonotus nidus-pici is a sterile conk which produces macrofungus, a neglected Central-Eastern
European relative of the prized Inonotus obliquus, also known as chaga. Investigation
of the methanol extract of the poroid fungus I. nidus-pici resulted in the isolation
of citropremide (1), 3,4-dihydroxybenzalacetone (2) , lanosterol (3), ergost-6,8,22-trien-3β-ol
(4), and ergosterol peroxide (5). The structures of fungal compounds were determined
on the basis of one- and two-dimensional NMR and MS spectroscopic analysis. Compounds
1–2 and 4–5 were evaluated for their antioxidant and antimicrobial properties against
several bacterial and fungal strains. 3,4-dihydroxybenzalacetone (2) and ergost-6,8,22-trien-3β-ol
(4) demonstrated moderate antimicrobial activity, while the former possessed notable
antioxidant activity in DPPH assay. The antiproliferative examinations performed on
three human cancer (MES-SA, MES-SA/Dx5, A431) cell lines demonstrated that compounds
4 and 5 have notable cytotoxic activity with IC values in micromolar range. The current
study represents the first report on the chemical profile of I. nidus-pici, providing
a comprehensive study on the isolation and structure determination of bioactive secondary
metabolites of this macrofungus.
