Using countercurrent chromatography to assist in the purification of new Annonaceous acetogenins fromAnnona squamosa

Three new Annonaceous acetogenins, (2,4-cis and trans)-9-hydroxy asimicinone (1), (2,4-cis and trans)-squamoxinone B (2) and (2,4-cis and trans) squamoxinone C (3), were isolated from the bark of Annona squamosa with the help of countercurrent chromatography. Additionally found was isoannoreticuin (4), which is new to this species. Compound 1 is an adjacent bis-tetrahydrofuran (THF) ring acetogenin with a hydroxyl group at the nine position and two more hydroxyls flanking the bis-THF system, while compounds 2–4 are all mono-THF ring acetogenins also possessing three hydroxyl groups. All four compounds are ketolactone-type acetogenins, and all show impressive cytotoxicities in a panel of six human tumour cell lines.