Research On Secondary Metabolites Of Six Microorganism

This paper consists of seven chapters.Chapter 1 summed up the research progress of triterpenoids and steroids compounds in fungi and their biological activities in the past five years.From Chapter 2 to Chapter 7,the chemical constituents of the fermentation products of Alternaria tenuissima,Agaricus villosa Brond,Flavocillium bifurcatum,Streptomyces sp.32065,Trichoderma sp.2-14F2,Trametes suaveloens（L.）Fr.fruiting body were studied.In this paper,the chemical compounds were separated by column chromatography and preparative liquid chromatography separation techniques.And the structure of compounds were identified by nuclear magnetic resonance spectroscopy,mass spectrometry,UV-visible spectroscopy and infrared spectroscopy.Finally,30 compounds,including 2new compounds were separated and identified.The compound structure involves various types,such as triterpenes,sterols,flavonoids,perylene quinones,pyrrolidone,amides,nucleosides,benzene ring derivatives and fatty acids.The antibacterial or antioxidant activities of some of the separated compounds were evaluated.Four compounds（1-4）were isolated and identified from the liquid fermentation of Flavocillium bifurcatum,including a new dioxane compound:Flavocatum A（1）;a new sulfonicacid compound:Flavocatum B（2）;one pyrimidine compound:uracil（3）;one benzene ring derivative:dibutyl phthalate（4）.Compounds 1-4 were isolated for the first time from Flavocillium bifurcatum.Four compounds（5-8）were isolated and identified from the liquid fermentation of Streptomyces sp.32065,including one flavonoid compound:apigenin（5）;one amide compound:N-（4-oxypentyl）-acetamide（6）;one fatty acid:linoleic acid（7）;one organic acid:lactic acid（8）.Compounds 6was isolated for the first time from Streptomyces sp..Eight compounds（9-16）were isolated and identified from the liquid fermentation of Agaricus villaticus Brond,including one steroid:（22E,24R）-5,8-peroxyergoste-6,22-diene-3β-Alcohol（9）;two benzene ring derivatives:dibutyl phthalate（10）,2-phenylethanol（11）;one fatty acid:n-pentadecanoic acid（12）;one fatty acid ester:triglyceride（13）;three polyols:2,3-butanediol（14）,glycerol（15）,1,2,3-trihydroxybutane（16）.compound 16 was a new natural product and compounds 9-16 were isolated for the first time from Agaricus villaticus Brond.Four compounds（17-20）were isolated and identified from Alternaria tenuissima,including two perylene quinones:Alterperylenol（17）,Altertoxins I（18）;two pyrrolidine diketone compounds:L-Tenuzonic acid（19）,D-allo-tenuazonic acid（20）.Compounds 19 and 20 were a pair of epimer,and separated by chiral chromatographic column.Seven compounds（21-27）were isolated and identified from the Trametes suaveloens（L.）Fr.fruiting body,including one lanostanoids compound:polylacticacidC（21）;onesteroid:（22E,24R）-5,8-peroxyergoste-6,22-diene-3β-Alcohol（22）;five fatty acids:oleic acid（23）,tetracosenoic acid（24）,arachidic acid（25）,linoleic acid（26）,lignoceric acid（27）.Compounds 21-27 were isolated for the first time from Trametes suaveloens（L.）Fr..Two compounds（28-29）were isolated and identified from Trichoderma sp.2-14F2,includingoneunsaturatedfattyacid:5-hydroxy-3-methylpent-2-enoic acid（28）and one lactone compound:methyl-2-（2-methoxy-2-oxoethyl）-4-oxooxetane-2-carboxylate（29）.Compound 29 was a new natural product and the NMR data was reported for the first time.Compounds 1,2,5-7,17-22 were tested for antioxidant activity.The results showed that compound 5 had significant antioxidant activity.DPPH,ABTS,hydroxyl radical with IC₅₀values of 0.027,0.132,0.635 mg/mL,respectively.The DPPH radical scavenging activity was better than the positive control.Compound 22 had good hydroxyl radical scavenging activity with IC₅₀value of 0.317 mg/mL.Compounds 1,2,17-21 were tested for antibacterial activities.Unfortunately,these compounds no significant inhibitory effect on Escherichia coli and Staphylococcus aureus.