Antibacterial And Antitumor Activity Analysis Of Halogenated Polyketide Zunyimycins

Objective: Antibacterial and antitumor activities of zunyimycins were analyzed,in order to provide new drugs for the treatments of tumor and infectious diseases.Methods:(1)The medium composition,cultural time,extraction conditions and other factors were optimized,for obtaining high yield of zunyimycin compounds.(2)The antibacterial activity of zunyimycin compounds against pathogens was tested by filter paper method.The "broth dilution method" was used to detect the minimum inhibitory concentration of zunyimycins.(3)To study the effect of zunyimycin C with different concentrations on the proliferation,several cell lines including,Hep G2,Hep1,MKC45,SGC7901,A549 and SCAP were cultivated in vitro.The inhibition rates were observed by MTT method after 8 h,12 h,24 h,36 h and 48 h respectively.(4)The effect of zunyimycin C(with concentrations of 8 ?M,16 ?M,32 ?M)combined with lipoic acid(50 ?M,500 ?M)on Hep G2 cells proliferation was assayed by MTT method.Results:(1)The content of target compounds would increase when strain was cultured on GYM medium with 1%(m/v)humic acid(soaked by ethanol)and extracted by ethyl acetate after 17 days.(2)The minimum inhibitory concentration values of zunyimycin A against MRSA,Enterococus and Bacillus subtilis were 6.89 ?g/m L,16.71 ?g/m L and 3.44 ?g/m L,respectively.The minimum inhibitory concentration values of zunyimycin B against MRSA,Enterococcus and Bacillus subtilis were 7.88 ?g/m L,12.81 ?g/m L and 3.94 ?g/m L,respectively.Meanwhile,the minimum inhibitory concentration of zunyimycin C against MRSA,Enterococcus and Bacillus subtilis were 3.75 ?g/m L,4.07 ?g/m Land 0.938 ?g/m L,respectively.(3)The values of median inhibitory concentration with different concentrations of zunyimycin C against Hep G2,Hep1,MKC45,SGC7901,A549 and SCAP cells were 13.97,22.55,21.49,44.71,27.47 and 18.3 ?M,respectively.(4)When the zunyimycin C of low concentration combined with lipoic acid,could promote the proliferation of Hep G2 cells.However,the high concentration of zunyimycin C combined with lipoic acid inhibited the Hep G2 cells proliferation.Conclusion:(1)The best cultural and extractive conditions of Streptomyces sp.FJS31-2 for obtaining high yield of zunyimycins compounds is confirmed.(2)zunyimycins showed good inhibitory activity against clinical isolates MRSA,Enterococcus,Staphylococcus aureus,Bacillus subtilis and other Gram-positive bacteria.Meanwhile,the antibacterial activity of zunyimycin C for clinical isolates MRSA,VRE was strongger.It will probably have an infectious potential for the treatment of MRSA and VRE pathogens.zunyimycin C could inhibit the proliferation of liver cancer,lung cancer and gastric cancer cells,which was of great significance to the development of new antitumor-drugs.