Abstract: Objective To study antimycobacterial activities in vitro of the compounds that target Mycobacterium tuberculosis β-ketoacyl-acyl carrier protein(ACP) synthase Ⅲ(FabH),and to obtain a novel,effective,and safe antituberculous agent. Methods The inhibitory diameters of compounds effect on M.phlei on agar plate were determined.The inhibitory effect of compounds on M.tuberculosis strain H37Rv and MDR-strain was tested on L-J media. Results The inhibitory diameters of 18 kinds of 500μmol/L compounds effect on M.phlei on agar plate were 1.8 to 2.4cm,respectively.The inhibitory diameters of 7 kinds of 250μmol and 125μmol compounds effect on M.phlei on agar plate were 1.5 to 2.2cm,respectively.18 kinds of 3mmol/L compounds inhibited obviously the growth of M. tuberculosis strain H₃₇R_v on L-J media at 2 weeks,and the compounds No.115, No.131,No.128,No.129,and No.137 also inhibited at 4 weeks.The compounds No.115 exhibited obvious inhibitory activity on M.tuberculosis MDR-strain HB240 inoculated on L-J media containing 11 kinds of compounds for 2 weeks and 4 weeks,respectively. Conclusion The most of compounds targeted fatty acid synthase FabH exhibited different degree of antimycobacterial activities,especially compounds No.115 had obvious inhibitory effect on M.phlei,M.tuberculosis strain H₃₇R_v and MDR-strain HB240.

Key words: FabH, Fatty acid synthase, β-ketoacyl-acyl carrier protein synthase Ⅲ, Antimycobacterial activity, Mycobacterium tuberculosis