Study On Secondary Metabolites Of Three Actinomycetes From Lichen And One Phoma Strain

In this paper,the secondary metabolites of three actinomycetes strains from lichen and one endophytic Phoma strain were studied.The strain Phoma sp.GZR 21 was obtained in the previous bioactivity screening of our research group.Three strains Amycolatopsis sp.YIM130687,Amycolatopsis sp.YIM130642 and Streptomyces sp.YIM130597 were obtained by TLC screening and antimicrobial screening from eleven strains of actinomycetes.A total of twenty-three compounds were isolated and identified from the four strains using various methods of isolation and purification,as well as spectroscopic analysis.Three compounds are new,including two polyketides isolated from the strain YIM 130687 and one drimane norsesquiterpenoid isolated from the strain Phoma GZR21.Thirteen compounds were obtained and identified from the culture broth of the strain YIM 130687,in which there are two new compounds(1 and 2).They were indentified as(E)-3-(hex-4-enoyl)-5,6-dihydroxy-1,5-dimethylbicyclo[2.2.0]hex-3-en-2-one(1)and 2,3,6-Trihydroxy-2,6-dimethyl-3-pent-3-enyl-cyclohexanone(2),respectively.The other known compounds were indentified as sorbicillin(3),2-proavoylaminobenzamide(4),2-(1-hydroxyethyl)-4(3H)quinazoline(5),acetotryptanide(6),2-actamidophenol(7),cyclo(L-Pro-L-Leu)(8),Cyclo(D-Pro-D-Phe)(9),tumagainolide B(10),(-)-4-hydroxy-l-teralone(11),p-hydroxyphenethyl alcohol(12)and campesterol(13).Four compounds were obtained and identified from the cluture broth of the strain YIM130642.They were indentified as prunetin(14),daidzein(15),phenylacetic acid(16),and cyclo(Leu-Tyr)(17).Compounds 14 and 15 are isoflavonoids.Four compounds were obtained and identified from the broth of the strain YIM 130597.They were indentified as tumagainolide B(10),campesterol(13),SF2738D(18)and SF2738F(19).Compounds 18 and 19 are bipyridine alkaloids.Four compounds were obtained and identified from the culture broth of the strain Phoma GZR21.Compound 20 is new and was indentified as 5a-hydroxy-9a-methyl-6-methylene-decahydro-naphtho[1,2-c]furan-3-one.The other known compounds were indentified as 6-methylsalicylic acid(21),gentisyl alcohol(22)and uracil(23).Compound 21 is a benzoic acid-derivative,which is the main product of this strain.Antimicrobial activity test showed that compound 3 had inhibitory activities against MRSA,Staphylococcus aureus,Escherichia coli and Salmonella typhimurium with minimum inhibitory concentration(MIC)values between 16-32?g/ml.Compounds 5 and 11 exhibited inhibitory effects against MRSA,with MIC values of 16?g/ml.Compound 6 showed inhibitory effect against MRS A and Staphylococcus aureus with MIC value of 32?g/ml.