Oblongionosides A-F, megastigmane glycosides from the leaves of Croton oblongifolius Roxburgh

► From Croton oblongifolius, megastigmane glycosides: oblongionosides A-F were isolated. ► Their structures were elucidated on the basis of spectroscopic data. ► Absolute structures were determined by HPLC analyses and the modified Mosher's method. ► Accumulation of HPLC data will establish a rule for diastereomeric pairs of megastigmanes.