Study On Chemical Constituents And Antimicrobial Activity Of The Fermentation Broth Produced By Clitocybe Infundibuliformis

There are many bioactive compounds exist in higher fungi, whose fermentation metabolites have become a research emphasis to look for novel bioactive compounds in medicine and pesticide development field. As research object, the myleium and fermentation broth of Clitocybe infundibuliformis (Schaeff.ex Fr.)Quél. which is a fungus of Tricholomataceae family, were selected for antimicrobial activities research and constituents research by modern isolation methods. The results are as follows.The fermentation metolites of Clitocybe infundibuliformis were selected for antibacterial activity test. The results showed that ethyl ecetate extracts have better activity than n-butanol extracts obviously. The ethyl acetate extract of fermentation broth had strong antibacterial effects on Staphylococcus aureus, Bacillus subtilis, Escherichia coli and Corynebacterium pakinense, while the ethyl acetate extract of mycelia exhibited notable inhibitory activity against Bacillus mesentericus.The minimum inhibitory concentration(MIC) of ethyl acetate extract of fermentation broth to Staphylococcus aureus and Escherichia coli were both 0.79 mg/mL.MIC of ethyl acetate extract from mycelia to Staphylococcus aureus, Bacillus megaterium, and Bacillus cereus were all 0.79 mg/mL as well. MIC of n-butanol extract of broth to Bacillus megaterium and Escherichia coli, as well as n-butanol extract of mycelia to Bacillus megaterium are all 1.57 mg/mL.The results of antimicrobial activity test to plant pathogenic fungi showed that the activity of fermentation metabolites went up with the concentration increasing.The inhibitory ratio at 6.25mg/mL of ethyl acetate extract from mycelia to Fusarium graminearum and Fusarium oxysporium f.sp.uasinfectum were 97.46% and 93.69% respectively. The n-butanol extract of mycelia could inhibit the plant pathogenic fungi prominently, whose inhibitory ratio to Alternaria brassicae and Fusarium graminearum were 93.93% and 96.45% at 6.25mg/mL.The ethyl acetate extract of mycelia was isolated and purified, four compounds were found.Comparing with the standard compounds,the compound I and compound II were identified as 4,6,8(14),22(23)-tetraen-3-one-ergostane and 5α,8-epidioxy- 22E,24R- ergosta- 6,22-dien-3β-ol. Compound III was identified as alternariol monomethyl ether(3,7-dihydroxy-9- methoxy-1- methyl-6H-benzo[c] chromen-6-one). Compound IV was identified as alternariol(3,4',5-trihydroxy-6'-methyldibenzo-α-pyrone).Compound III and compound IV were firstly found in higher fungi.