The isolation and purification of the leaves of Kopsia singapurensisRidl. (Apocynaceae) revealed the presence of steroids, terpenes, and alkaloids. Stigmasterol 1 was isolated from the hexane crude extract of the leaves of this species. This phytochemical study involves extraction, separation by using various chromatographic methods and structural determination by spectroscopic technique such as IR, NMR including 1D-NMR (1H, 13C and DEPT), 2D-NMR (COSY, NOESY, HMQC/HSQC, and HMBC) and GCMS, involving also comparison with data from the literature..

4582 hits

This study was aimed to extract and identify chemical compounds isolated from the leaves and barks of Kopsia singapurensis. The isolated compounds were evaluated for cytotoxic (MCF-7), antibacterial (Bacillus cereus) and antioxidant activity (DPPH). The isolation process was carried out using chromatographic techniques such as column chromatography and thin layer chromatography. The structures of isolated compounds were elucidated through spectroscopic analysis including 1D-NMR (1H, 13C and DEPT), 2D-NMR (1H-1H COSY, HSQC/HMQC and HMBC), IR, UV, MS (GCMS); also by comparison with previous literature data. Isolation study on the leaves of K. singapurensis has yielded lupeol 147, mixture of stigmasterol 148 and β- sitosterol 149, lupeol ester 150, and a mixture of lupeol 147, α-amyrin 151 and β- amyrin 152. Compounds β-amyrin 152, β-amyrenone 153, β-amyrin acetate 154 and lupeol acetate 155 were successfully isolated from the bark of K. singapurensis. These triterpenoids were isola.....

706 hits

In Malaysia, Alstonia spathulata Bl. is locally known as ‘Pulai Basong’ which distribute in peat forest. The separation of the chemical components from hexane and DCM crude extract of Alstonia spathulata was carried out using column chromatography (CC) and thin layer chromatography (TCL) techniques. A total of five known compound were isolated from the stem bark extracts and identified as: β-amyrin, β-amyrin acetate, lupeol acetate, stigmasterol and β-sitosterol. The elucidation structures of these compounds were established using 1D-NMR (1H, 13C and DEPT) and 2D-NMR (COSY, HSQC, HMBC) spectroscopic analysis, involving also comparison with data from the literature...

2286 hits