Abstract
Bio-assay guided fraction of the methanolic extract of Annona glabra seeds (Annonaceae), cultivated in Egypt, revealed to the isolation of three bis-tetrahydrofuran acetogenins; squamocin-C (1), squamocin-D (2), and annonin I (3). Compounds 1 and 2 were obtained as stereoisomeric mixture. All isolates were assayed for their cytotoxicity twards brine shrimp and five in vitro cancer cell lines (A549, HT29, MCF 7, RPMI, and U251), and showed significant activity The structures of all compounds were determined by interpretation of their NMR and MS analyses.