Abstract: Compound A4 isolated from the seeds of Annona squamosa L. was a new compound with structural characteristics of adjacent bis-tetrahydrofuran and seco-bis-tetrafuranyl annonaceous acetogenins. A4 was found as the first example of this new type of seco-tris-tetrahy- drofuranyl annonaceous acetogenins and was named annonsilin A.

Key words: Annona squamosa, Seco-tris-tetrahydrofuranyl annonaceous acetogenins, Annonsilin A