Thesis (M.Sc.)--Chulalongkorn University, 2012

The investigation for chemical constituents and their biological activities from the Hexane and CH2Cl2 crude extracts of the stem barks of Erythrina stricta led to the isolation of six known compounds, p-hydroxybenzoic acid (1), osajin (2), derrone (3), erythinasinate (4), and a mixture of β-sitosterol (5) and stigmasterol (6). All isolated compounds were evaluated for their cytotoxicity on KB, HeLa, MCF-7, HepG-2, Colo205, and LLC cells. Compound 2 exhibited moderate cytotoxicity against both KB and Colo205 cells with IC50 values of 14.5 and 9.74 µg/mL and exhibited weak cytotoxicity against HeLa, MCF-7, HepG-2, and LLC cells with IC50 values of 21.8, 16.9, 17.4, and 16.3 µg/mL, respectively. Compound 3 exhibited weak activity against all the tested cells (KB, HeLa, MCF-7, HepG-2, Colo205, and LLC cells) with IC50 values of 15.8, 19.1, 17.3, 20.1, 15.2, and 17.1 µg/mL, respectively. Other compounds gave only very high IC50 values and were regarded as inactive to these cytotoxicity assays. The investigation for chemical constituents and their biological activities from the CH2Cl2 and acetone crude extracts of the stem bark of E. subumbrans led to the isolation of six known compounds, p-hydroxybenzoic acid (1), erythinasinate (4), and a mixture of β-sitosterol (5) and stigmasterol (6), hexacosyl trans-ferulate (7), and lupeol (8). All isolated compounds were evaluated for their cytotoxicity on KB, HeLa, MCF-7, HepG-2, Colo205, and LLC cells. Compound 8 exhibited moderate cytotoxicity against most of the tested cells including KB, HeLa, HepG-2, Colo205, and LLC cells with IC50 values of 14.0, 13.9, 13.7, 7.97, and 10.6 µg/mL respectively, whereas it exhibited weak cytotoxicity against MCF-7 cells with IC50 value of 16.7 µg/mL. On the other hand, other compounds gave only very high IC50 values and were regarded as inactive to these cytotoxicity assays.