Objective:To investigate the chemical compositions from the stems of Murraya microphylla and their anti-fungal activity against eight plant fungal pathogens in vitro. Method:The compounds were isolated and purified by the normal phase silica gel

Sephadex LH-20 HPLC column chromatography and other methods. Their structures were identified on the basis of spectral analysis such as 1H-NMR

13 C-NMR and MS. Their anti-fungal activity was evaluated by the mycelium growth rate method. Result:Eleven compounds were obtained and identified as girinimbine (1)

mahanimbine (2)

koenimbine (3)

koenidine (4)

mukonal (5)

murrayanine (6)

murrayaquinone-B (7)

β-sitosterol (8)

daucosterol (9)

3β-hydroxystigmast-5-en-7-one (10)

and tetracosanoic acid

methyl ester (11)

respectively. Even at the high concentration of 200 mg·L-1

carbazoles 1-7 exhibited different anti-fungal activity against these fungi in vitro

especially for M. grisea. Compounds 6 and 1 showed a broad spectrum and potent activity against these fungal pathogens

exhibiting a high activity against M. grisea

with IC50 values of 65.81

161.61 mg·L-1

respectively. Conclusion:Compounds 2-3

5-7 were isolated from the plant for the first time. Compounds 1 and 6 had great potentials for further research and development.