Putrescine bisamides from Aglaia gigantea.

Phytochemical analysis of the leaves of Aglaia gigantea collected in Vietnam yielded three cinnamoyl putrescine bisamide derivatives, which included the known compound dasyclamide ( 1), as well as two new natural products, gigantamide A ( 2) and grandiamide D ( 3). In this study, the structure of dasyclamide ( 1) was confirmed by X-ray crystallography. The structures of the two new alkaloids, gigantamide A ( 2) and grandiamide D ( 3), were elucidated through extensive 1D and 2D NMR spectroscopy and analysis of their mass spectrometric (ESIMS, HRQTOFMS) data. The absolute configuration of grandiamide D ( 3) was determined via Mosher ester derivatization.