Antiproliferative glabretal-type triterpenoids from the root bark of Dictamnus dasycarpus

Four new glabretal-type triterpenoids, dictabretols A-D (1-4), were isolated by activity-guided fractionation from the root bark of Dictamnus dasycarpus T. (Rutaceae) using an in vitro antiproliferative assay on T cells using splenocytes. The structures of these compounds were determined by spectroscopic methods, including 2D NMR experiments. Compounds were evaluated for their immunosuppressive activity on T cells and demonstrated inhibition of proliferation of activated T cells, up to IC50 of 1.5μM.