| Aim:A set of methods for fermentation, extraction, and screening of the microbial metabolites for antitumor activities was established in our previous work. Crude extracts of two strains Streptomyces sp.3423 and Streptomyces sp.2215 metabolites were found to show strong inhibition on K562 cell line but weak inhibition on normal Vero cells.Both extracts showed selective inhibition on tumor cells,but the active compounds are unkown. In this paper, we studied on the active metabolites of these two strains,including fermentation,extraction,isolation,structure elucidation and testing their activities.Methods:Streptomyces sp.3423 and Streptomyces sp.2215 were fermented in shake flask or fermentation tank,and the broth were extracted by AcOEt and purified by serial process such as silica chromatography,C18 chromatography,Sephadex LH-20,preparative TLC and HPLC. The structure of compounds were determined by IR,FAB-MS,1H-NMR, 13C-NMR,1H-1HCOSY,HSQC,HMBC etc.The anti-tumor activities of compounds which isolated from the two strepomyces.sp were assessed by MTT,and the inhibitory on expression of BCR-ABL were assessed by western-blot.Results:Six cyclopeptide analogues were isolated from Streptomyces sp.3423 and are identified to be1:1 -N-methyl-3-benzylidene-6-isobutylidene-piperazine-2,5-dione; 2:3-benzyl-6-isobutyl- piperazine-2,5-dione; 3:3-benzylidene-6-isobutyl- piperazine-2,5-dione; 4: 3-benzyl-6-isobutylidene-piperazine-2,5-dione; 5: 3-Benzylidene-6-isobutylidene-piperazine-2,5-dione(albonoursin); 6: 3-Hydroxy-5-methoxy-6-methyl-2,3-dihydro-pyran-4-one;Three compounds were isolated from Streptomyces sp.2215 and identified to be compound 7:monosulfoxide quinomycine, compound 8:quinomycine A, compound 9:palmitic acid.Compounds 1,5,7,8 show inhibitory activities on K562 cell line,with IC50 is 13.8μg/ml,4.05μg/ml, 34.01ng/ml and 0.015ng/ml respectively; Western-blot indicate that compounds 5,7,8 show inhibitory on expreesion of BCR-ABL. |
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