AbstractThe aim of this study was to extract and identify the chemical compounds isolated from Alstonia spathulata and Kopsia singapurensis. The isolated compounds were tested for their biological activities include cytotoxicity (MCF-7 cell line), antibacterial (Bacillus cereus) and antioxidant (DPPH). The separation of the chemical components from both species was carried out using different chromatographic techniques (column chromatography and thin layer chromatography). The structures of isolated compounds have been elucidated through spectral analysis including 1D-NMR (1H, 13C and DEPT), 2D-NMR (1H-1H COSY, HSQC/HMQC and HMBC), IR, UV, MS (GCMS) and also by comparison with previous literature data. Studies on the chemical constituents of the bark of Alstonia spathulata has led to the isolation of five triterpenes; β-amyrin 113, β-amyrin acetate 114, β-sitosterol 115, lupeol acetate 116, stigmasterol 117 and a mixture of three triterpenes (lupeol 118, α-amyrin 119 and β-amyrin 113). Fo.....