UPSI Digital Repository (UDRep)
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Total records found : 4 |
Simplified search suggestions : Tan Siow Ping Nafiah Mohd Azlan Ahmad Kartini |
1 | 2012 conference_item | Isolation Of Stigmasterol from the leaves of Kopsia Singapurensis RIDL Lee Yean Shan, Ahmad Kartini, Awang Khalijah, Tan Siow Ping, Nafiah Mohd Azlan, 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.. 4342 hits |
2 | 2012 conference_item | Chemical Constituent from Alstonia Spathulata BL. (Apocynaceae) Tee Chuan Thing, Ahmad Kartini, Awang Khalijah, Tan Siow Ping, Nafiah Mohd Azlan, In Malaysia, Alstonia spathulataBl. is locally known as pulai basong which distribute in peat forest. The separations of the chemical components from hexane crude extract (bark) of Alstonia spathulata were carried out using different chromatographic techniques (column chromatography and thin layer chromatography). One compound were isolated and identified as lupeol acetate (1). This compound have never been reported and isolated from this species. The structures of this compound were elucidated based on the basis of detailed 1D-NMR (1H, 13C and DEPT) and 2DNMR (COSY, HSQC, HMBC) spectroscopic analysis. The data analysis was also compared with the literature... 4170 hits |
3 | 2014 article | C23-Carbazole Alkaloids from the bark of Murraya koenigii (L.) Spreng Tan Siow Ping, Nafiah Mohd Azlan, Ahmad Kartini, Murraya koenigii (Rutaceae), locally known as curry leaf tree, is a medicinally important herb of Indian origin and now is widely distributed throughout southern Asia. The bark of Malayan Murraya koenigii was investigated for phytochemical content. The isolation of chemical constituents from its hexane extract was carried out by using various chromatographic techniques. Spectroscopic methods, including NMR, IR, UV, MS spectra data, were used for the structural characterization. Four C23-carbazole alkaloids were isolated.. 2000 hits |
4 | 2014 article | Phytochemical study of stem bark from Alstonia spathulata Bl. (Apocynaceae) Tee Chuan Thing, Lee Yean Shan, Tan Siow Ping, Awang Khalijah, Nafiah Mohd Azlan, Ahmad Kartini, 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... 2129 hits |