Two New Anisic Acid Derivatives from Endophytic Fungus Rhizopycnis vagum Nitaf22 and Their Antibacterial Activity

Abstract

Rhizopycnis acids A (<b>1</b>) and B (<b>2</b>), two new anisic acid derivatives, were obtained from the ethyl acetate extract of the fermentation cultures of <i>Rhizopycnis vagum</i>, an endophytic fungus isolated from the healthy tissues of <i>Nicotiana tabacum</i>. The structures of the two compounds were determined through a series of 1D and 2D NMR and HRMS spectral analyses. Both compounds were the first anisic acid derivatives containing methylbutanoic/methylbutenoic acid group found in fungi. <b>1</b> and <b>2</b> displayed antibacterial activity against six tested bacteria with IC₅₀ values in the range 16.1~81.3 μg/mL.