The fungus Xylaria sp.KYJ-15 was isolated from Illigera celebica.Based on the one strain many compounds(OSMAC)strategy,the strain was fermented on potato and rice solid media,respectively.As a result,two novel steroid...The fungus Xylaria sp.KYJ-15 was isolated from Illigera celebica.Based on the one strain many compounds(OSMAC)strategy,the strain was fermented on potato and rice solid media,respectively.As a result,two novel steroids,xylarsteroids A(1)and B(2),which are the first examples of C28-steroid with an unusualβ-andγ-lactone ring,respectively,along with two new dihydroisocoumarin glycosides,xylarglycosides A(3)and B(4),were identified.Their structures were elucidated by spectroscopic methods,X-ray diffraction and electronic circular dichroism(ECD)experiments.All isolated compounds were evaluated for cytotoxicity,DPPH radical scavenging activity,acetylcholinesterase inhibitory and antimicrobial effect.Compound 1 exhibited potent AChE inhibitory activity with an IC50 value of 2.61±0.05μmol·L^(−1).Theβ-lactone ring unit of 1 is critical for its AChE inhibitory activity.The finding was further confirmed through exploring the interaction of 1 with AChE by molecular docking.In addition,both compounds 1 and 2 exhibited obvious antibacterial activity against Bacillus subtilis with a minimum inhibitory concentration(MIC)of 2μg·mL^(−1).Compounds 3 and 4 exhibited antibacterial activities against Staphylococcus aureus with MICs of 4 and 2μg·mL^(−1),respectively,which also exhibited DPPH radical scavenging activity comparable to the positive control with IC50 values of 9.2±0.03 and 13.3±0.01μmol·L^(−1),respectively.展开更多
文摘The fungus Xylaria sp.KYJ-15 was isolated from Illigera celebica.Based on the one strain many compounds(OSMAC)strategy,the strain was fermented on potato and rice solid media,respectively.As a result,two novel steroids,xylarsteroids A(1)and B(2),which are the first examples of C28-steroid with an unusualβ-andγ-lactone ring,respectively,along with two new dihydroisocoumarin glycosides,xylarglycosides A(3)and B(4),were identified.Their structures were elucidated by spectroscopic methods,X-ray diffraction and electronic circular dichroism(ECD)experiments.All isolated compounds were evaluated for cytotoxicity,DPPH radical scavenging activity,acetylcholinesterase inhibitory and antimicrobial effect.Compound 1 exhibited potent AChE inhibitory activity with an IC50 value of 2.61±0.05μmol·L^(−1).Theβ-lactone ring unit of 1 is critical for its AChE inhibitory activity.The finding was further confirmed through exploring the interaction of 1 with AChE by molecular docking.In addition,both compounds 1 and 2 exhibited obvious antibacterial activity against Bacillus subtilis with a minimum inhibitory concentration(MIC)of 2μg·mL^(−1).Compounds 3 and 4 exhibited antibacterial activities against Staphylococcus aureus with MICs of 4 and 2μg·mL^(−1),respectively,which also exhibited DPPH radical scavenging activity comparable to the positive control with IC50 values of 9.2±0.03 and 13.3±0.01μmol·L^(−1),respectively.
