title: Six cytotoxic annonaceous acetogenins from Annona squamosa seeds.
abstract: Custard apple (Annona squamosa L.) is an edible tropical fruit, and its seeds had been used in south China as a folk medicine to treat "malignant sore" (cancer) and as an insecticide. Phytochemical investigation of the ethanol fraction of custard apple seeds led to the isolation of six new annonaceous acetogenins: annosquacins A-D (1-4), annosquatin A (5) and annosquatin B (6). Their structures were elucidated by spectroscopic analysis. Compounds 1-4 are adjacent bistetrahydrofuran annonaceous acetogenins. Compounds 5 and 6 are non-adjacent bistetrahydrofuran annonaceous acetogenins and the first examples in which the tetrahydrofuran ring system is located between C-9 and C-20. The absolute configurations of 1-6 were defined by the application of the Mosher method. Compounds 1-6 exhibited potent cytotoxic activity in vitro against five human tumour cell lines. Compounds 5 and 6 showed a high selectivity toward the MCF-7 and A-549 cell line respectively.
authors.affiliation: College of Pharmacy, Nanjing University of Chinese Medicine, 138 Xianlin Road, Nanjing 210046, PR China.
authors.forename: Yong
authors.initials: Y
authors.lastname: Chen
authors.forename: Jian-Wei
authors.initials: JW
authors.lastname: Chen
authors.forename: Yu
authors.initials: Y
authors.lastname: Wang
authors.forename: Sha-Sha
authors.initials: SS
authors.lastname: Xu
authors.forename: Xiang
authors.initials: X
authors.lastname: Li
mesh_terms: D054378:Acetogenins / Q000737:chemistry / Q000633:toxicity*; D031041:Annona / Q000737:chemistry*; D045744:Cell Line, Tumor; D002470:Cell Survival / Q000187:drug effects; D006801:Humans; D015394:Molecular Structure; D010936:Plant Extracts / Q000737:chemistry / Q000633:toxicity*; D012639:Seeds / Q000737:chemistry
chemical_list: D054378:Acetogenins; D010936:Plant Extracts