A new sesquiterpene from seeds of Cassia occidentalis and its cytotoxicity

For the purpose of finding new bioactive agents from ethnic medicines, the chemical study on Dai Medicine Cassia occidentalis was carried out. The chemical constituents from the seeds of C. occidentalis were isolated by column chromatographic methods on silica gel, MCI-Gel resin, Sephadex LH-20, and high performance liquid chromatography. Their structures were elucidated by spectroscopic methods, including extensive 1D and 2D NMR techniques. The cytotoxicity of the compound for NB4, A549, SHSY5Y, PC3, and MCF7 cells line was also assayed by using the MTT method. Two sesquiterpenes (1 and 2) were isolated from this plant. Compound 1 is a new compound and named as methyl 6-(hydroxymethyl)-4-isopropyl-7-methoxynaphthalene-1-carboxylate. Compound 1 also displayed high cytotoxicity with the tested cancer cell-lines.