Anthracycline Derivatives In The Actinomycete TB040209 And Their Antitumor Activity

Anthracyclines,as a natural antibiotic,are a class of antitumor drugs with wide clinical application and are very effective against a wide range of tumors,including breast cancer.Actinomycetes are one of the largest producers of naturally occurring active compounds and are likewise an important source of anthracyclines.In this thesis,we collected soil from Tibet,isolated 300 strains of Actinobacteria,and screened strain TB040209 by TLC spot plate observation as well as liquid phase analysis.We performed gene framework map test analysis on the selected strains and submitted the full gene sequencing results to antiSMASH for analysis,and we found that the strains contained class II polyketide biosynthesis genes corresponding to anthracycline(doxorubicin)compounds.After large-scale fermentation of the strain,the monomeric compounds were separated by silica gel column chromatography(CC),preparative thin layer chromatography(PTLC),and preparative high performance liquid chromatography(RP-HPLC),and finally five anthracyclines were isolated(ε-rhodomycinone,daunomycinone,doxorubicinone,baumycin C1,7-[α-L-daunosamino]-aklavinone).In a previous study,ε-Rhodomycinone was found to be of great research value because of its low cardiotoxicity and its ability to inhibit the proliferation,invasion and metastasis of human breast cancer cells.Therefore,we chose ε-rhodomycinone,daunomycinone and doxorubicinone,which have similar structures toε-rhodomycinone,as the parent structures,and introduced acyl groups at different positions of the hydroxyl groups in the side chains to obtain compounds with good activity and selectivity.17 derivatives were synthesized in this thesis.All compounds were docked with DNA molecules by molecular docking software,and all compounds were found to be inserted into DNA molecules,indicating their ability to interfere with DNA replication transcription and exert anti-cancer effects.Four cell cytotoxic activities of human breast cancer cells MCF-7,human breast cancer cells MDA-MB-453,human breast cancer cells MDA-MB-231 and human normal breast cells MCF-10A were screened by the MTT method.Analysis of the experimental data revealed that a total of 15 compounds exhibited varying degrees of cytotoxic activity against breast cancer cells.Among them,all the compounds isolated from Actinomyces were found to have some cytotoxic activity,and the compound TM-2 had the best activity and was active against all cancer cells.Among the derivatives,derivative TM-34 showed the best activity with an IC50 value of 7.7175±0.47μM against breast cancer cells MCF-7,which showed elevated activity compared to the parent structure.The IC50 value against normal breast cells was 18.665 ± 1.51 μM,which was about 2.5 times higher than that of tumor cells,and the selectivity was also elevated compared to the parent structure.The above data suggest that the work in this thesis has some significance as well as reference value for the discovery of anthracyclines and their structural modifications.