Fig. 5.

Comparison of epoxy-4,5-α-dihydroxysantonin (EDHS) (A) to its parent compound, santonin (B). The structure of the sesquiterpene lactone parent compound santonin compared to the epoxidated derivative, EDHS. (C) In an ATP-Lite assay with the HL60 variant, RV+ cells, no protective or mitogenic activity was detected in the absence of ²²⁵Ac (circle) and presence (triangle) of isotope. Means were not significantly different among all groups. (D) Treatment of HL60 (open) or RV+ cells (closed) with EDHS has no effect on nuclide accumulation. EDHS (square) or 1% dimethylsulfoxide (v/v) (circle) was incubated along with ²²⁵Ac for indicated time points before pellets were washed and counted for gamma activity. For each panel, values are means (n ≥ 3), and error bars indicate ± SEM.