Studies on the bioactive constituents of the fermented broths and mycelia of two fungus species isolated in Taiwan

• Main Authors: Ya-Ching Tsaur, 曹雅菁
• Other Authors: 李宗徽
• Format: Others
• Language: zh-TW
• Published: 2009
• Online Access: http://ndltd.ncl.edu.tw/handle/75091585411990614956

碩士 === 臺北醫學大學 === 生藥學研究所 === 97 === In this study, 34 strains of fungus isolated in Taiwan were cultured for the screening of iNOS (inducible nitric oxide synthase) inhibitory activities, and among them, the fermented broths or mycelia of 13 fungus species exhibited significant activities on the inhibition of NO production in lipopolysaccharides (LPS) activated mouse macrophage RAW264.7. Based on this findings, 2 strains of fungus including Psathyrella velutina (#96110901) and Neosartorya sp. (#325) were thus selected to investigate their bioactive constituents. A series of bioassay-guided chemical examination on the fermented broth or mycelia of these two strains were carried out, which resulted in the isolation of ten compounds. Their structures were elucidated to be psathyrone (1), 5-hydroxymethylfurfural (2), bis-2,5-hydroxymethylfuran (3), 2-(4-hydroxy-2-octyl-5-oxotetrahydrofuran-3-yl)acrylic acid (6), 2-(4-hydroxy-2-octyl-5-oxotetrahydrofuran-3-yl)acrylic acid methyl ester (7), maltol (8), succinic acid (9), fumaric acid (10), and a mixture of (22E,24S)-24-methylnorcholesta-5,7,22-trien-3β-ol (4), and (22E,24R)-24-methylnorcholesta-5,7,22-trien-3β-ol (5)(1：1) on the basis of spectroscopic analysis. Of these compounds identified, psathyrone (1) was a new compound with a rare 5/6/5/6-fused ring system, and 6 and 7 were isolated for the first time from natural resources. The bioactivities of all the pure entities were further evaluated. The results of biological tests indicated that 6 and 7 exhibited significant activities on the inhibition of NO production in lipopolysaccharides (LPS) activated macrophage RAW264.7 with IC50 values of 12.17 ± 1.49 and 11.36 ± 0.97 μM, respectively.