In the course of screening for new biological actives, an unidentified fungal strain (FA2277) was found to produce several cytotoxic substances including a new aspochalasin analog. Aspochalasins which are structurally related to cytochalasins, well-known mycotoxins, were first isolated as metabolic products of Aspergillus microcysticus1) and few compounds of this group have been characterized to date2,3). This paper briefly describes the fermentation, isolation, structural studies, and cytotoxic activity of aspochalasin E, a new aspochalasin analog (Fig. 1).