Study On Antimicrobial And Chemical Constituents Of Fermentation Extracts Of Oudemansiella Mucida Fr.

There are many officinal and agrochemical compounds from higher fungi. Therefore, research on fungi has attracted people's attention and become to be explored and developed new drugs. This thesis dealt with the study on the antimicrobial activities and chemical composition of Oudemansiella mucida, with the methods of isolation of modern chemistry and techniques of Phytochemistry. The antimicrobial activities of the obtained fermentation broths were determined and the isolation, purification and determination of chemical components of EtOAc extracts from mycelia were taken in succession. The results were as followed:Their antimicrobial activities of EtOAc and n-BuOH extracts were determined by filter paper method and solid culture medium method. The results showed that EtOAc extracts exhibited significant activity against Bacillus subtilis and Bacillus mesentericu; n-BuOH extracts exhibited good activity against Bacillus cereus; the remained fermentation broths exhibited weak activity against Escherichia coli and Enterobacter aerogenes. Along with lower concentration of the EtOAc and n-BuOH extracts, the antimicrobial activities were significantly reduced. The fermentation broths of Oudemansiella mucida had no prominent antimicrobial activity against bacteria.The fermentation broths of Oudemansiella mucida showed notable antimicrobial activity against fungi; especially EtOAc extracts displayed prominent antimicrobial activity. EtOAc extracts markedly inhibited five phytopathologenic fungi, with the minimal inhibiting concentration (MIC) for Alternaria brassicae, Alternaria longipes and Gloesporum fructigenum being 10 mg/mL, the MIC for Fusarium graminearum and Alternaria alternata being 5mg/mL.Fraction D2 which were isolated from the EtOAc extracts, were analyzed by GC-MS, The result showed that seven fatty acids were defined from mycelia. Fraction D2 contained saturated fatty acids 79.44%---Lauric acid 25.74%, Myristic acid 5.31%, Palmitic acid 39.48%, Stearic acid 6.6%; D2 also contained unsaturated fatty acids 20.56%---Linoleic acid and Linolenic acid 5.33%, Oleic acid 15.23%.The EtOAc extract of mycelia was isolated through colum chromatographys, and purified by Sephedex LH-20. Three compounds were found and identified by FAB-MS, 1HNMR, 13CNMR, DEPT, then compared with the references and standard compounds were also used to test.They are ergosta-4,6,8(14), 22-tetraen-3-one; 5α,8α-epidioxy-(22E, 24R)-ergosta-6,22-dien-3β-ol, Hexahydropyrrolo[1,2-α]pyrazine-1,4-dione.