Further bioactivity-directed fractionation of the ethanol extract of the seeds of Annona cherimolia has led to the isolation of two mono-tetrahydrofuran acetogenins, xylomaticin (1) and gonionenin (2). The structures of these compounds were characterized on the basis of chemical and spectroscopic data. Compounds 1 and 2 have a relative stereochemistry relationship of threo/trans/threo across the mono-tetrahydrofuran ring with its two flanking hydroxyls. Compounds 1 and 2 are known, but are first isolated from this plant. In brine shrimp lethality test (BST), 1 and 2 exhibited cytotoxic activity.