Objective: This study was carried out to study the chemical constituents from of Polyalthia oblique. Method: Compounds from 95% ethanolic extract of P. oblique were isolated by column chromatography on silica gel

Sephadex LH-20

together with recrystallization

and their structures were identified by their physical characteristics and spectral features. Result: Eight compounds were isolated from P. oblique

and identified as alkaloids isooncodine (1)

pendulamine A (2)

three steroids stigmasta-4-ene-3

6-dione (3)

β-sitosterol (4)

stigmasterol (5)

and three other compounds including hydroquinone (6)

vanillin (7)

octadecadienoic acid (8). Conclusion: All compounds were isolated from P. oblique for the first time. Compound 3 showed inhibition activity against Escherichia coli

with minimal inhibitory concentrations(MIC) value of 5 mg·L-1. Compound 1 showed weak inhibition activities against SPC-A-1 and A-549 tumor cells

with IC50 values of 78.6

49.3 mg·L-1.