Abrusamide A and B, two hepatoprotective isomeric compounds from Abrus mollis Hance

Abstract Two isomeric compounds, abrusamide A ( 1 ) and abrusamide B ( 2 ), were isolated from the leaves of Abrus mollis Hance. Their structures were well defined by means of UV, HR–ESI–MS, 1 H NMR, 13 C NMR and 2D NMR techniques. From a biogenetic point of view, these two compounds including a cyclobutane basic core should be considered as a [2+2] dimerization product of ( E )- N -(4-hydroxycinnamoyl) tyrosine ( 3 ), which was also isolated from the plant for the first time. They were also tested for their hepatoprotective effects on human L-02 cells and displayed significant promote effects on the proliferation of L-02 cells and significant hepatoprotective effects on CCl 4 -induced injury of L-02 cells.