Free-Radical Scavenging Activities of Cultured Mycelia of Paecilomyces hepiali (Ascomycetes) Extracts and Structural Characterization of Bioactive Components by Nuclear Magnetic Resonance Spectroscopy

摘要

Current research is focused on testing the cultivation of Paecilomyces hepiali mycelia on various plant substrates and producing fungus or mycelial biomass with qualitatively interesting substances. P. hepiali mycelia was cultivated using solid-state fermentation of different substrates. Mycelial biomass was then analyzed, and antioxidant activity was evaluated using the DPPH radical scavenging method for different ethanolic extracts based on a millet substrate (extract 1) or a chickpea substrate (extract 2). Extract 1 corresponds to a half-maximal DPPH radical inhibitory concentration of 1.73 mg/mL; the inhibitory concentration of ethanol extract 2 was almost 4.5 times higher at 7.92 mg/mL. Extracts 1 and 2 were separated into fractions by column chromatography and the chemical structures were determined for the substances that formed the most effective fraction of sample 1. The chemical structures of all compounds in the most active fraction of sample 1 were analyzed by H-1, C-13, distortionless enhancement by polarization transfer, correlation spectroscopy, heteronuclear single-quantum correlation spectroscopy, and heteronuclear multiple-bond correlation spectra.