Bioactivity-directed fractionation of the leaf extract of Annona muricata L. (Annonaceae) has resulted in the isolation of two new Annonaceous acetogenins, annomuricine (1) and muricapentocin (2). Compounds 1 and 2 are monotetrahydrofuran ring acetogenins bearing two flanking hydroxyl groups; however, each has three additional hydroxyl groups. Compound 1 has an erythro 1,2-diol, and 2 has a 1,5,9-triol moiety. Both 1 and 2 showed significant cytotoxicities against six types of human tumors, with selectivities to the pancreatic carcinoma (PACA-2) and colon adenocarcinoma (HT-29) cell lines.