Abstract: Compound 1,with resuscitating activity on dormant Mycobacterium tuberculosis, was isolated from Fissistigmacavaleriei root by bioassay-guided method. It was identified as β-sitosterol-9,12-hexadecadienoate by physical and spectroscopic methods. Compound 1 showed activity to resuscitate dormant Mycobacterium tuberculosis into active state in a dose-dependent manner with minimum effective concentration of 16 μg/mL.Dormant M.tuberculosis was insensitive to isoniazid,ethambutol,rifamicin and pyrazinamide in single drug. At the concentration of 32 μg/mL,Compound 1 canhelp isoniazid to kill dormant M.tuberculosis after 14 and 21 days of exposure,and increase the killing activity of rifamicin against dormant M.tuberculosis. However,among two-drug combinations,compound 1-ethambutol andcompound 1-pyrazinamide,exhibited antagonistic action on dormant M.tuberculosis. Compound 1 can activate the KatG activity of dormant M. tuberculosis, which caused the content of O₂ in dormant M.tuberculosis cells at a high level to trigger the resuscitation of dormant M. tuberculosis.

Key words: FissistigmaCavaleriei, dormant Mycobacterium tuberculosis, resuscitating, mechanism