4-methylthio-butanyl derivatives from the seeds of Raphanus sativus

Raphanus sativus L. (Brassicaceae) has long been cultivated as a food crop in Korea. The seeds have been used in Korean traditional medicine as a therapeutic agent for carminative, diuretic, expectorant, laxative and stomachic. Some glucosinolates have been isolated from the seeds of R. sativus. Glucosinolates and/or their breakdown products have recently attracted considerable interest because of their cancer-preventive properties. In our screening test, the MeOH extract of the seeds of R. sativus exhibited significant cytotoxicity against some human tumor cells and anti-inflammatory activity by inhibiting LPS-induced NO production. The purification of the MeOH extract from the seeds of R. sativus using repeated column chromatography afforded four new 4-methylthio-butanyl derivatives (1–4), together with four known ones (5–8). The structures of the new compounds were elucidated by analysis of 1D and 2D NMR data. We are studying the anti-neuroinflammatory effects of isolates for their inhibitory effects on nitric oxide (NO) production in lipopolysaccharide (LPS)-activated BV-2 cells.