Eudesmane sesquiterpene glucosides from lychee seed and their cytotoxic activity

Two new sesquiterpene glucosides, litchiosides A (1) and B (2), were obtained along with pumilaside A (3) and funingensin A (4) from lychee (Litchi chinensis Sonn.) seed. Their structures were elucidated on the basis of spectroscopic and chemical evidence. The in vitro antitumour activity of compounds 1–4 against A549, LAC, Hela, and Hep-G2 cell lines was determined using the MTT colourimetric assay. Pumilaside A (3) exhibited significant activity against all the tested cell lines with IC50 values of 0.012–6.29 μM, and funingensin A (4) showed moderate activity against Hep-G2 cells (IC50 = 39.27 μM), while litchiosides A (1) and B (2) were found to be inactive.