Two new alkaloids, mappine A (1) and mapposidic acid (2), together with eleven known compounds, were isolated from the stems of Mappianthus iodoides Hand.-Mazz. Their structures were elucidated by means of spectroscopic and mass-spectrometric analyses, particularly 1D-and 2D-NMR spectroscopy. The cytotoxic activities of the two new alkaloids were also evaluated.Introduction. -The genus Mappianthus (Icacinaceae family) consists of three species which are distributed in subtropical and tropical zone. Mappianthus iodoides Hand.-Mazz., one species occurring in China, is used by local people for the treatment of traumatic injury, rheumatalgia, arthralgia, etc.[1].There were no phytochemical studies on this genus except that a sesquiterpene named (À)-cedrol had been reported from Mappianthus iodoides Hand.-Mazz.[2]. Our phytochemical investigation on the 95% EtOH extract of the title plant led to the isolation of 13 compounds, comprising seven alkaloids, i.e., mappine A (1), mapposidic acid (2) . The above compounds were reported for the first time from this genus. Here, we report on the isolation and structure elucidation of the two new alkaloids 1 and 2, and the evaluation of their cytotoxic activities.

A new naphthoquinone, 6-hydroxy-a-dunnione (1) and a new binaphthoquinone, methyl 1,1',4,4'-tetrahydro-3-hydroxy-1,1',4,4'-tetraoxo[2,2'-binaphthalene]-3'-carboxylate (2), along with ten known compounds, including naphthoquinones, anthraquinones, and phenylethanoid glucosides, were isolated from the roots of Didymocarpus hedyotideus Chun. Their structures were identified by spectroscopic analyses, particularly 1D-and 2D-NMR spectroscopy. The cytotoxic activities of the two new naphthoquinones were also evaluated.