Antimicrobial secondary metabolites of an endolichenic Aspergillus niger isolated from lichen thallus of Parmotrema ravum .

A new 6-benzyl-γ-pyrone ( 1 ), named aspergyllone was isolated from the culture filtrates of an endolichenic fungus Aspergillus niger Tiegh, obtained from lichen thallus Parmotrema ravum (Krog & Swinscow) Serus, collected in India. 1 was isolated for the first time from an endolichenic fungus together with six other known metabolites identified as aurasperones A ( 2 ) and D ( 3 ), asperpyrone A ( 4 ), fonsecinone A ( 5 ), carbonarone A ( 6 ) and pyrophen ( 7 ). The compounds were tested against a panel of human, plant, food borne and fish pathogens. Aspergyllone showed strong selective antifungal activity against Candida parapsilosis (Ashford) Langeron & Talice, with an IC ₅₀ of 52 µg/mL. Aurasperone A and pyrophen showed moderate to strong antimicrobial activity inhibiting seven different test pathogens, being pyrophen active with IC ₅₀ ranging from 35 to 97 µg/mL.[Formula: see text].