Sulfur-Containing Spiroketal Glycosides from Breynia fruticosa

Phytochemical investigation of the chemical constituents of the aerial parts of Breynia fruticosa afforded 10 sulfur-containing spiroketal glycosides, including eight new compounds (1-8) and two known compounds, epibreynin B (9) and breynin B (10). Epibreynin B (9) was previously reported as a semisynthetic oxidation product of breynin A and is now reported from a natural source for the first time. The structures of 1-10 were determined on the basis of spectroscopic and chemical methods.