Isolation and characterization of an antimalarial agent of the neem tree Azadirachta indica

The isolation and structure elucidation of gedunin 1, the antimalarial agent of Azadirachta indica, are reported. Its 1H- and 13C-nmr spectra were assigned by using one- and two-dimensional nmr spectroscopy, especially homonuclear and heteronuclear COSY, nOe difference, and COLOC experiments.